Externalising disorders - research Flashcards

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1
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Thapar (2018)

A

gene studies suggest ADHD is a trait along a continuum

persistent ADHD is associated with higher genetic loading

however…

common gene variants are only weakly predictive

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2
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Kibby (2018)

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The term “processing speed” (PS) encompasses many components including perceptual, cognitive and output speed. Despite evidence for reduced PS in Attention-Deficit/Hyperactivity Disorder (ADHD), little is known about which component(s) is most impacted in ADHD, or how it may vary by subtypes. Participants included 151 children, ages 8–12 years, with ADHD Predominantly Inattentive Type, ADHD Combined Type and typically developing controls using DSM-IV criteria. All children completed four measures of processing speed: Symbol Search, Coding, Decision Speed, and simple reaction time. We found children with ADHD-PI and ADHD-C had slower perceptual and psychomotor/incidental learning speed than controls and that ADHD-PI had slower decision speed than controls. The subtypes did not differ on any of these measures. Mean reaction time was intact in ADHD. Hence, at a very basic output level, children with ADHD do not have impaired speed overall, but as task demands increase their processing speed becomes less efficient than controls’. Further, perceptual and psychomotor speed were related to inattention, and psychomotor speed/incidental learning was related to hyperactivity/impulsivity. Thus, inattention may contribute to less efficient performance and worse attention to detail on tasks with a higher perceptual and/or psychomotor load; whereas hyperactivity/impulsivity may affect psychomotor speed/incidental learning, possibly via greater inaccuracy and/or reduced learning efficiency. Decision speed was not related to either dimension. Results suggest that PS deficits are primarily linked to the inattention dimension of ADHD but not exclusively. Findings also suggest PS is not a singular process but rather a multifaceted system that is differentially impacted in ADHD.

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3
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Salvi et al. (2019)

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Introduction. Attention Deficit Hyperactivity Disorder (ADHD) is an early onset clinical condition characterized by attention difficulties, hyperactivity and impulsivity which can persist across the lifespan, significantly influencing the evolutionary course and facilitating the rise of psychiatric comorbidities. The presence of different ADHD subtypes in adults is a heterogeneity factor to be recognized in order to orient prognosis and treatment, as indicated by studies that described differences in the characterization of different subtypes in relation to both severity and comorbidities. Materials and methods. In the present study we evaluated the socio-demographic and clinical characteristics of a sample of adults with ADHD and the characteristics associated with the different disorder subtypes. We described 60 patients aged between 18 and 65 years (mean age 34.1) with primary diagnosis of ADHD consecutively admitted to the Regional Centre for diagnosis and treatment of ADHD in adults in Milan. Results. We observed high severity of symptoms and low quality of life, in particular in the “life outlook” dimension. The subtypes distribution was the following: 18.3% inattentive subtype, 8.3% hyperactive/impulsive subtype and 70% combined subtype. The hyperactive/impulsive subtype showed a significantly higher frequency in females, while the inattentive subtype was more frequent in males. Patients with the hyperactive/impulsive subtype showed worse quality of life and more frequent anxiety disorders. Conclusions. Considering the different clinical profiles among various subtypes, these data add relevance to subtypes classification of adult ADHD.

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4
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Bralten et al. (2013)

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Objective: Because multiple genes with small effect sizes are assumed to play a role in attention-deficit/hyperactivity disorder (ADHD) etiology, considering multiple variants within the same analysis likely increases the total explained phenotypic variance, thereby boosting the power of genetic studies. This study investigated whether pathway-based analysis could bring scientists closer to unraveling the biology of ADHD. Method: The pathway was described as a predefined gene selection based on a well-established database or literature data. Common genetic variants in pathways involved in dopamine/norepinephrine and serotonin neurotransmission and genes involved in neuritic outgrowth were investigated in cases from the International Multicentre ADHD Genetics (IMAGE) study. Multivariable analysis was performed to combine the effects of single genetic variants within the pathway genes. Phenotypes were DSM-IV symptom counts for inattention and hyperactivity/impulsivity (n = 871) and symptom severity measured with the Conners Parent (n = 930) and Teacher (n = 916) Rating Scales. Results: Summing genetic effects of common genetic variants within the pathways showed a significant association with hyperactive/impulsive symptoms (p(empirical) = .007) but not with inattentive symptoms (p(empirical) = .73). Analysis of parent-rated Conners hyperactive/impulsive symptom scores validated this result (P-empirical = .0018). Teacher-rated Conners scores were not associated. Post hoc analyses showed a significant contribution of all pathways to the hyperactive/impulsive symptom domain (dopamine/norepinephrine, p(empirical) = .0004; serotonin,. P-empirical = .0149; neuritic outgrowth, p(empirical) = .0452). Conclusion: The present analysis shows an association between common variants in 3 genetic pathways and the hyperactive/impulsive component of ADHD. This study demonstrates that pathway-based association analyses, using quantitative measurements of ADHD symptom domains, can increase the power of genetic analyses to identify biological risk factors involved in this disorder.

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5
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Riley et al. (2008)

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Objective: The purpose of this study was to evaluate whether preschool children with attention-deficit/hyperactivity disorder predominantly hyperactive-impulsive type (ADHD-HI) and ADHD combined type (ADHD-C) have different levels of functional impairment in four domains: externalizing (oppositional and disruptive) behaviors, internalizing (anxious) behaviors, social skills, and preacademic functioning. Methods: The subjects were 102 children 3 to 5 years of age, meeting DSM-IV criteria for ADHD. Children with ADHD-C versus ADHD-HI were compared across at least two measures for each of the four functional domains. oppositional and anxious behaviors were assessed on the Conners Parent and Teacher Rating Scales. In addition, off-task and disruptive behaviors were assessed by direct observation in the preschool setting. Social skills were assessed on the parent and teacher versions of the Social Skills Rating System and preacademic skills were assessed on the letter word identification, passage comprehension, and applied problems. subtests of the Woodcock-Johnson III Tests of Achievement and the initial sound fluency subtest of the Dynamic indicators of Basic Early Literacy Skills 5th Edition. Results: There were no significant differences between the groups on rating scale T scores for parent-reported oppositional symptoms (ADHD-C vs ADHD-HI; 66.7 +/- 13.5 vs 65.7 +/- 11.7; p = .73); parent-reported anxious symptoms (53.5 +/- 11.1 vs 53.2 +/- 9.7; p = .90); teacher-reported oppositional symptoms (70.9 +/- 15.6 vs 75.5 +/- 14.7; p = .17); or teacher reported anxious symptoms (59.2 +/- 11.6 vs 58.5 +/- 12.2; p = .77). No statistically significant differences were found between the groups when examining off-task and/or disruptive behavior during structured and free play observations at school. No significant differences between the subtypes were found for social skills or preacademic functioning. Conclusions: Across the four areas of functioning assessed in this study, preschool children with ADHD-HI and those with ADHD-C demonstrated similar levels of functioning. This study, in combination with data from longitudinal studies demonstrating that most children with ADHD-HI are later diagnosed with ADHD-C, suggests that ADHD-HI may represent an earlier form of ADHD-C as opposed to a distinct subtype.

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6
Q

Bluschke (2018)

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It is far from conclusive what distinguishes the inattentive (ADD) and the combined (ADHD-C) subtype of ADHD on the neuronal level. Theoretical considerations suggest that especially interval timing processes may dissociate these subtypes from each other. Combining high-density EEG recordings with source localization analyses, we examine whether there are ADHD-subtype specific modulations of neurophysiological processes subserving interval timing in matched groups of ADD (n = 16), ADHD-C (n = 16) and controls (n = 16). Patients with ADD and ADHD-C show deficits in interval timing, which was correlated with the degree of inattention in ADD patients. Compared to healthy controls, patients with ADHD-C display a somewhat weaker, yet consistent response preparation process (contingent negative variation, CNV). In patients with ADD, the early CNV is interrupted, indicating an oscillatory disruption of the interval timing process. This is associated with activations in the supplemental motor areas and the middle frontal gyrus. Patients with ADD display adequate feedback learning mechanisms (feedback-related negativity, FRN), which is not the case in patients with ADHD-C. The results suggest that altered pacemaker-accumulation processes in medial frontal structures distinguish the ADD from the ADHD-C subtype. Particularly in patients with ADD phasic interruptions of preparatory neurophysiological processes are evident, making this a possible diagnostic feature.

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7
Q

Oie et al. (2014)

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The aim of the present study was to investigate the ability of children with attention deficit/hyperactivity disorder-combined subtype (ADHD-C) and predominantly inattentive subtype (ADHD-PI) to direct their attention and to exert cognitive control in a forced attention dichotic listening (DL) task. Twenty-nine, medication-naive participants with ADHD-C, 42 with ADHD-PI, and 40 matched healthy controls (HC) between 9 and 16 years were assessed. In the DL task, two different auditory stimuli (syllables) are presented simultaneously, one in each ear. The participants are asked to report the syllable they hear on each trial with no instruction on focus of attention or to explicitly focus attention and to report either the right- or left-ear syllable. The DL procedure is presumed to reflect different cognitive processes: perception (nonforced condition/NF), attention (forced-right condition/FR), and cognitive control (forced-left condition/FL). As expected, all three groups had normal perception and attention. The children and adolescents with ADHD-PI showed a significant right-ear advantage also during the FL condition, while the children and adolescents in the ADHD-C group showed a no-ear advantage and the HC showed a significant left-ear advantage in the FL condition. This suggests that the ADHD subtypes differ in degree of cognitive control impairment. Our results may have implications for further conceptualization, diagnostics, and treatment of ADHD subtypes.

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8
Q

Polanczyk et al. (2007)

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Objective: The worldwide prevalence estimates of attention deficit hyperactivity disorder (ADHD)/hyperkinetic disorder (HD) are highly heterogeneous. Presently, the reasons for this discrepancy remain poorly understood. The purpose of this study was to determine the possible causes of the varied worldwide estimates of the disorder and to compute its worldwide-pooled prevalence. Method: The authors searched MEDLINE and PsycINFO databases from January 1978 to December 2005 and reviewed textbooks and reference lists of the studies selected. Authors of relevant articles from North America, South America, Europe, Africa, Asia, Oceania, and the Middle East and ADHD/HD experts were contacted. Surveys were included if they reported point prevalence of ADHD/HD for subjects 18 years of age or younger from the general population or schools according to DSM or ICD criteria. Results: The literature search generated 9,105 records, and 303 full-text articles were reviewed. One hundred and two studies comprising 171,756 subjects from all world regions were included. The ADHD/HD worldwide-pooled prevalence was 5.29%. This estimate was associated with significant variability. In the multivariate metaregression model, diagnostic criteria, source of information, requirement of impairment for diagnosis, and geographic origin of the studies were significantly associated with ADHD/HD prevalence rates. Geographic location was associated with significant variability only between estimates from North America and both Africa and the Middle East. No significant differences were found between Europe and North America. Conclusions: Our findings suggest that geographic location plays a limited role in the reasons for the large variability of ADHD/HD prevalence estimates worldwide. Instead, this variability seems to be explained primarily by the methodological characteristics of studies.

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9
Q

Sayal et al. (2018)

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Attention-deficit hyperactivity disorder (ADHD) is a common childhood behavioural disorder. Systematic reviews indicate that the community prevalence globally is between 2% and 7%, with an average of around 5%. At least a further 5% of children have substantial difficulties with overactivity, inattention, and impulsivity that are just under the threshold to meet full diagnostic criteria for ADHD. Estimates of the administrative prevalence (clinically diagnosed or recorded) vary worldwide, and have been increasing over time. However, ADHD is still relatively under-recognised and underdiagnosed in most countries, particularly in girls and older children. ADHD often persists into adulthood and is a risk factor for other mental health disorders and negative outcomes, including educational underachievement, difficulties with employment and relationships, and criminality. The timely recognition and treatment of children with ADHD-type difficulties provides an opportunity to improve long-term outcomes. This Review includes a systematic review of the community and administrative prevalence of ADHD in children and adolescents, an overview of barriers to accessing care, a description of associated costs, and a discussion of evidence-based pathways for the delivery of clinical care, including a focus on key issues for two specific age groups—younger children (aged ≤6 years) and adolescents requiring transition of care from child to adult services.

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10
Q

Thomas et al. (2015)

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METHODS: Medline, PsycINFO, CINAHL, Embase, and Web of Science were searched for studies with point prevalence estimates of ADHD. We included studies of children that used the diagnostic criteria from DSM-III, DSM-III-R and DSM-IV in any language. Data were extracted on sampling procedure, sample characteristics, assessors, measures, and whether full or partial criteria were met.

RESULTS: The 175 eligible studies included 179 ADHD prevalence estimates with an overall pooled estimate of 7.2% (95% confidence interval: 6.7 to 7.8), and no statistically significant difference between DSM editions. In multivariable analyses, prevalence estimates for ADHD were lower when using the revised third edition of the DSM compared with the fourth edition (P = .03) and when studies were conducted in Europe compared with North America (P = .04). Few studies used population sampling with random selection. Most were from single towns or regions, thus limiting generalizability.

CONCLUSIONS: Our review provides a benchmark prevalence estimate for ADHD. If population estimates of ADHD diagnoses exceed our estimate, then overdiagnosis may have occurred for some children. If fewer, then underdiagnosis may have occurred.

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11
Q

Willcutt (2012)

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This article describes a comprehensive meta-analysis that was conducted to estimate the prevalence of attention-deficit/hyperactivity disorder (ADHD), as defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV). A systematic literature review identified 86 studies of children and adolescents (N = 163,688 individuals) and 11 studies of adults (N = 14,112 individuals) that met inclusion criteria for the meta-analysis, more than half of which were published after the only previous meta-analysis of the prevalence of ADHD was completed. Although prevalence estimates reported by individual studies varied widely, pooled results suggest that the prevalence of DSM-IV ADHD is similar, whether ADHD is defined by parent ratings, teacher ratings, or a best estimate diagnostic procedure in children and adolescents (5.9–7.1 %), or by self-report measures in young adults (5.0 %). Analyses of diagnostic subtypes indicated that the predominantly inattentive type is the most common subtype in the population, but individuals with the combined type are more likely to be referred for clinical services. Additional research is needed to determine the etiology of the higher prevalence of ADHD in males than females and to clarify whether the prevalence of ADHD varies as a function of socioeconomic status or ethnicity. Finally, there were no significant prevalent differences between countries or regions of the world after controlling for differences in the diagnostic algorithms used to define ADHD. These results provide important support for the diagnostic validity of ADHD, and argue against the hypothesis that ADHD is a cultural construct that is restricted to the United States or any other specific culture.

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12
Q

Simon et al. (2009)

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Method
We used the MEDLINE, PsycLit and EMBASE databases as well as hand-searching to find relevant publications.

Results
The pooled prevalence of adult ADHD was 2.5% (95% CI 2.1–3.1). Gender and mean age, interacting with each other, were significantly related to prevalence of ADHD. Metaregression analysis indicated that the proportion of participants with ADHD decreased with age when men and women were equally represented in the sample.

Conclusions
Prevalence of ADHD in adults declines with age in the general population. We think, however, that the unclear validity of DSM–IV diagnostic criteria for this condition can lead to reduced prevalence rates by underestimation of the prevalence of adult ADHD.

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13
Q

Polanczyk et al. (2014)

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Methods: We updated the two most comprehensive systematic reviews on ADHD prevalence available in the literature. Meta-regression analyses were conducted to test the effect of year of study in the context of both methodological variables that determined variability in ADHD prevalence (diagnostic criteria, impairment criterion and source of information), and the geographical location of studies.

Results: We identified 154 original studies and included 135 in the multivariate analysis. Methodological procedures investigated were significantly associated with heterogeneity of studies. Geographical location and year of study were not associated with variability in ADHD prevalence estimates.

Conclusions: Confirming previous findings, variability in ADHD prevalence estimates is mostly explained by methodological characteristics of the studies. In the past three decades, there has been no evidence to suggest an increase in the number of children in the community who meet criteria for ADHD when standardized diagnostic procedures are followed.

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14
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Barkley (2003)

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This paper provides a brief overview of the nature of attention-deficit/hyperactivity disorder (ADHD) in children and the current criteria used in its clinical diagnosis. While the disorder continues to be viewed as one of inattention and/or hyperactive-impulsive behavior, theories of ADHD are beginning to focus more on poor inhibition and deficient executive functioning (self-regulation) as being central to the disorder. Problems have been identified by research pertaining to the clinical diagnostic criteria outlined in the DSM-IV that, at present, remain unresolved. Clinicians should be aware of these problems and the adjustments that need to be made to them when dealing with special populations that were not represented in the field trials used to develop these criteria.

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15
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Li et al. (2018)

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Despite many studies reporting a variety of alterations in brain networks in patients with attention deficit hyperactivity disorder (ADHD), alterations in hemispheric anatomical networks are still unclear. In this study, we investigated topology alterations in hemispheric white matter in patients with ADHD and the relationship between these alterations and clinical features of the illness. Weighted hemispheric brain anatomical networks were first constructed for each of 40 right-handed patients with ADHD and 53 matched normal controls. Then, graph theoretical approaches were utilized to compute hemispheric topological properties. The small-world property was preserved in the hemispheric network. Furthermore, a significant group-by-hemisphere interaction was revealed in global efficiency, local efficiency and characteristic path length, attributed to the significantly reduced hemispheric asymmetry of global and local integration in patients with ADHD compared with normal controls. Specifically, reduced asymmetric regional efficiency was found in three regions. Finally, we found that the abnormal asymmetry of hemispheric brain anatomical network topology and regional efficiency were both associated with clinical features (the Adult ADHD Self-Report Scale and Wechsler Adult Intelligence Scale) in patients. Our findings provide new insights into the lateralized nature of hemispheric dysconnectivity and highlight the potential for using brain network measures of hemispheric asymmetry as neural biomarkers for ADHD and its clinical features.

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16
Q

Dorr and Armstrong (2019)

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Objective: To better understand current issues with adult ADHD assessment contributing to adult ADHD being under recognized and undertreated. Method: This study examined the relationship between symptoms, impairment, and executive functioning (EF) in a college sample. Results: Among individuals screening negative for ADHD, those higher in EF experienced significantly less impairment than those lower in EF. Executive functioning was shown to have a negative relationship with impairment while ADHD symptomology was shown to have a positive relationship with impairment. In addition, impairment was significantly predicted by ADHD symptom level and EF, and there was a significant interaction between EF and ADHD symptom level in predicting impairment. However, high EF did not significantly protect against impairment in individuals reporting a significant level of ADHD symptoms. Conclusion: Further research is needed to clarify the relationships between these variables in emerging adult college students.

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17
Q

Tamm et al. (2019)

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Reaction time variability (RTV) is a ubiquitous phenomenon in Attention-Deficit/Hyperactivity Disorder (ADHD). Few studies have examined RTV in relation to functional outcomes such as social impairment in children with ADHD. In this exploratory study, we investigated whether RTV is associated with social functioning in children at risk for ADHD. Specifically, we explored the association between RTV (tau derived from correct go trials of a Stop-Signal task) and social functioning in 198 children ages 7-12 years referred for an ADHD evaluation. Social functioning measures included child and/or parent ratings of social competence, aggression, social problems, and impairment in relationships. In regression analyses that also included Oppositional Defiant Disorder symptoms and sex, higher RTV was significantly associated with lower ratings of social competence, and higher proactive/reactive aggression ratings on the child self-report measures. RTV was not significantly associated with parent report of social functioning or relationship impairment. This study provides preliminary evidence that RTV may be associated with social functioning in children at risk for ADHD. We propose that lapses of attention affecting cognitive control may also negatively impact social information processing thereby affecting social functioning. Replication is warranted and longitudinal studies are needed to investigate whether RTV predicts social dysfunction in ADHD.

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18
Q

Larsson (2019)

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19
Q

Lin and Gau (2019)

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Methods
We followed up 53 individuals diagnosed with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) ADHD during childhood (mean age 12.77 years at time 1, 19.81 years at time 2) and 50 non-ADHD controls (mean age 12.80 years at time 1, 19.36 years at time 2) with repeated psychiatric interviews at two time points to confirm ADHD and other psychiatric diagnoses. Neuropsychological functions with high- and low-executive demands, measured by the Cambridge Neuropsychological Testing Automated Battery (CANTAB) at two time points, were compared.

Results
Both groups showed improvements in all neuropsychological tasks except reaction time in the ADHD group. Despite having a greater improvement in spatial working memory (SWM) than controls, individuals with ADHD still performed worse in various neuropsychological tasks than controls at follow-up. Better baseline intra-dimension/extra-dimension shift and parental occupation predicted fewer ADHD symptoms at follow-up independent of baseline ADHD symptoms. The degree of ADHD symptom reduction was not significantly linearly correlated to the magnitude of neuropsychological function improvement.

Conclusion
Individuals with ADHD and controls had parallel developments in neuropsychological functioning, except a catch-up in SWM in ADHD. Almost all neuropsychological functions herein were still impaired in ADHD at late adolescence/young adulthood. There may be a threshold (i.e. non-linear) relationship between neuropsychological functioning and ADHD symptoms.

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20
Q

Brocki et al. (2017)

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Objective: The role of heterogeneous self-regulation deficits in ADHD has long been emphasized. Yet, longitudinal studies examining distinct self-regulation processes as prospective predictors of developmental change in ADHD symptoms spanning wide developmental periods are scarce. The aim of the current study was to examine affective and cognitive self-regulation as predictors of developmental change in ADHD symptoms from preschool to adolescence in a sample with one third of the children being at risk for developing an ADHD and/or ODD diagnosis. Method: At 5 years laboratory measures for hot and cool executive function (EF) and parental and teacher ratings were used for regulation of positive and negative emotionality. Symptoms of ADHD and ODD were measured at 5 and 13 years using parental and teacher ratings based on the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV). Results: Converging developmental paths in hyperactivity/impulsivity across time were found for those high versus low in early cognitive self-regulation, whereas the development of inattention symptoms diverged across time for those high versus low in early affective self-regulation. Conclusion: These results support the idea that different aspects of self-regulation are important for developmental change in the two separate ADHD symptom domains from preschool to adolescence.

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21
Q

Willcutt (2019)

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22
Q

Lapalme et al. (2017)

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The developmental course of attention-deficit/hyperactivity disorder (ADHD) symptoms (inattention, hyperactivity, impulsivity) from childhood to adolescence was described and compared based on parent and teacher report as a function of co-occurring conduct disorder/oppositional defiant disorder (CD/ODD) over 6 years. The moderating effect of gender was investigated. Participants were 291 children (6–13 years old; 79 girls) with ADHD: 91 with ADHD only and 200 with ADHD+CD/ODD. At study entry, boys and girls in the ADHD+CD/ODD group presented significantly more hyperactivity symptoms based on parent report and more impulsivity symptoms based on teacher report than did those in the ADHD-only group. ADHD symptoms, however, diminished on average over time in both groups, according to both parent and teacher report. However, as children in the ADHD+CD/ODD group, particularly girls, presented more symptoms at study entry, they tended to remain above the diagnostic threshold 6 years later. This suggests an association exists between co-occurring CD/ODD and ADHD persistence.

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23
Q

Faraone and Larsson (2019)

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Decades of research show that genes play an vital role in the etiology of attention deficit hyperactivity disorder (ADHD) and its comorbidity with other disorders. Family, twin, and adoption studies show that ADHD runs in families. ADHD’s high heritability of 74% motivated the search for ADHD susceptibility genes. Genetic linkage studies show that the effects of DNA risk variants on ADHD must, individually, be very small. Genome-wide association studies (GWAS) have implicated several genetic loci at the genome-wide level of statistical significance. These studies also show that about a third of ADHD’s heritability is due to a polygenic component comprising many common variants each having small effects. From studies of copy number variants we have also learned that the rare insertions or deletions account for part of ADHD’s heritability. These findings have implicated new biological pathways that may eventually have implications for treatment development.

Attention deficit hyperactivity disorder (ADHD) is a childhood-onset condition with impairing symptoms of inattention, impulsivity, and hyperactivity. Decades of research have documented and replicated key facts about the disorder (for a review, see ref. [1]). It occurs in about 5% of children with little geographic or cross-cultural variation in prevalence and often co-occurs with other conditions, including mood, anxiety, conduct, learning, and substance use disorders. Longitudinal studies show that two-thirds of ADHD youth will continue to have impairing symptoms of ADHD in adulthood. People with ADHD are at risk for a wide range of functional impairments: school failure, peer rejection, injuries due to accidents, criminal behavior, occupational failure, divorce, suicide, and premature death. Although many details of ADHD’s pathophysiology are unknown, neuropsychological and neuroimaging studies implicate brain circuits regulating executive functioning, reward processing, timing, and temporal information processing.

This article reviews data about the role that genes play in the etiology of ADHD from two perspectives. Family, twin, and adoption studies provide a firm foundation for asserting that genes are involved in the etiology of ADHD. The view from molecular genetics provides a basis for understanding mechanisms whereby genes affect biological pathways that lead to ADHD.

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24
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Quiroga et al. (2016)

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Objective: The aim of this study was to assess for the first time the criterion validity of the semi-structured Diagnostic Interview for ADHD in adults (DIVA 2.0), and its concurrent validity in comparison with the Conners’ Adult ADHD Diagnostic Interview for DSM-IV (CAADID) and other ADHD severity scales, following the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria. Method: A transversal study was performed on 40 out-patients with ADHD to check the criteria and concurrent validity of the DIVA 2.0 compared with the CAADID. Results: The DIVA 2.0 interview showed a diagnostic accuracy of 100% when compared with the diagnoses obtained with the CAADID interview. The concurrent validity demonstrated good correlations with three self-reported rating scales: the Wender Utah Rating Scale (WURS; r = .544, p < .0001), the ADHD-Rating Scale (r = .720, p < .0001), and Sheehan’s Dysfunction Inventory (r = .674, p < .0001). Conclusion: The DIVA 2.0 is a reliable tool for assessing and diagnosing Adult ADHD and is the only one that offers free online access for clinical and research purposes.

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25
Q

Asherson et al. (2016)

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For many years, attention-deficit hyperactivity disorder (ADHD) was thought to be a childhood-onset disorder that has a limited effect on adult psychopathology. However, the symptoms and impairments that define ADHD often affect the adult population, with similar responses to drugs such as methylphenidate, dexamphetamine, and atomoxetine, and psychosocial interventions, to those seen in children and adolescents. As a result, awareness of ADHD in adults has rapidly increased and new clinical practice has emerged across the world. Despite this progress, treatment of adult ADHD in Europe and many other regions of the world is not yet common practice, and diagnostic services are often unavailable or restricted to a few specialist centres. This situation is remarkable given the strong evidence base for safe and effective treatments. Here we address some of the key conceptual issues surrounding the diagnosis of ADHD relevant to practising health-care professionals working with adult populations. We conclude that ADHD should be recognised in the same way as other common adult mental health disorders, and that failure to recognise and treat ADHD is detrimental to the wellbeing of many patients seeking help for common mental health problems.

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26
Q

Salvi et al. (2019)

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Introduction. Attention Deficit Hyperactivity Disorder (ADHD) is an early onset clinical condition characterized by attention difficulties, hyperactivity and impulsivity which can persist across the lifespan, significantly influencing the evolutionary course and facilitating the rise of psychiatric comorbidities. The presence of different ADHD subtypes in adults is a heterogeneity factor to be recognized in order to orient prognosis and treatment, as indicated by studies that described differences in the characterization of different subtypes in relation to both severity and comorbidities. Materials and methods. In the present study we evaluated the socio-demographic and clinical characteristics of a sample of adults with ADHD and the characteristics associated with the different disorder subtypes. We described 60 patients aged between 18 and 65 years (mean age 34.1) with primary diagnosis of ADHD consecutively admitted to the Regional Centre for diagnosis and treatment of ADHD in adults in Milan. Results. We observed high severity of symptoms and low quality of life, in particular in the “life outlook” dimension. The subtypes distribution was the following: 18.3% inattentive subtype, 8.3% hyperactive/impulsive subtype and 70% combined subtype. The hyperactive/impulsive subtype showed a significantly higher frequency in females, while the inattentive subtype was more frequent in males. Patients with the hyperactive/impulsive subtype showed worse quality of life and more frequent anxiety disorders. Conclusions. Considering the different clinical profiles among various subtypes, these data add relevance to subtypes classification of adult ADHD.

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27
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Abecassis et al. (2017)

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Attention-deficit/hyperactivity disorder (ADHD) is a developmental disorder that persists into adulthood for many individuals. Research on the disorder, however, has largely focused on childhood or on adulthood but spanning a very broad age range. Emerging adulthood, conceptualized as the period between 18 and 29 years of age, has been identified as a distinct developmental stage. To date, there is relatively little research focused specifically on ADHD in that period of life. In the present paper, we provide an overview of the characteristics of ADHD in emerging adults. The prevalence of ADHD in this stage of life appears to be slightly higher than typically found in studies with adult samples of broader age range. ADHD in emerging adults is associated with a variety of negative outcomes such as poorer academic and occupational functioning, psychiatric comorbidities, alcohol and substance use, as well as stimulant misuse. Studies using neuropsychological tests have generally reported average to high average intellectual functioning, variable performance on measures of attention, and generally intact scores on most measures of executive functions. In contrast, a small number of studies indicate the presence of subjective executive dysfunction. Methodological limitations that likely contribute to heterogeneity in the literature are discussed.

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28
Q

Fruchter et al. (2019)

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Objective: To assess the functioning of young adults with ADHD in a military setting. Method: In all, 14,655 young adults with ADHD (mean age at first examination 17.8 +/- 0.7) attending mandatory service in the Israeli military were compared with matched controls on several functioning domains. Results: Young adults with ADHD had more sessions with mental health care professionals, physician appointments, sick days, and disqualifications of professions than controls (p < .001). Young adults with ADHD were also less medically fit for combat service (odds ratio [OR] = 0.75, 95% confidence interval [CI] = [0.72, 0.79]), more medically unfit for military service in general (OR = 1.26, 95% CI = [1.13, 1.40]), and had higher rates of overweight and obesity (p < .001). In addition, they were more likely to be diagnosed with a personality disorder (OR = 1.29, 95% CI = [1.07, 1.53]) or with minor affective and anxiety disorders (OR = 1.33, 95% CI = [1.06, 1.67]) than matched controls. Conclusion: These results support a negative effect of ADHD on the functioning of young adults in a military setting.

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29
Q

Thorell et al. (2019)

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Purpose and aim: The overall aim of the present study was to examine quality of life in attention deficit hyperactivity disorder (ADHD) patients age >= 60 years. First, we compared older adults with ADHD to both healthy controls of the same age and younger adults with ADHD. Second, we examined executive functioning as a possible underlying factor for quality of life among older adults with ADHD. Methods: The study included 158 participants in three groups: (1) older adults (60-75 years of age) with ADHD (n = 42), (2) healthy controls of the same age (n = 58), and (3) younger adults (age 18-45 years of age) with ADHD (n = 56). The patients with ADHD were clinically-referred. Quality of life was examined through self-ratings and executive functioning was examined using both self-ratings and tests. Results: Older adults with ADHD differed significantly from controls the same age on all aspects of quality of life, with large effect sizes. However, they showed similar levels of quality of life compared to younger adults with ADHD. The exception was psychological health, for which older adults displayed better quality of life compared to younger adults with ADHD. Executive deficits measured through self-ratings, especially working memory, were related to quality of life, sometimes also beyond the influence of ADHD symptom levels. Conclusions: Older adults with ADHD show serious impairments in quality of life, that are comparable to the levels found for younger adults. Impairments may increase further as these individuals grow older and clinics need to meet the needs of this increasingly larger group of patients.

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30
Q

Faraone et al. (2005)

A

Results of behavioral genetic and molecular genetic studies have converged to suggest that both genetic and nongenetic factors contribute to the development of attention-deficit/hyperactivity disorder (ADHD). We review this literature, with a particular emphasis on molecular genetic studies. Family, twin, and adoption studies provide compelling evidence that genes play a strong role in mediating susceptibility to ADHD. This fact is most clearly seen in the 20 extant twin studies, which estimate the heritability of ADHD to be .76. Molecular genetic studies suggest that the genetic architecture of ADHD is complex. The few genome-wide scans conducted thus far are not conclusive. In contrast, the many candidate gene studies of ADHD have produced substantial evidence implicating several genes in the etiology of the disorder. For the eight genes for which the same variant has been studied in three or more case-control or family-based studies, seven show statistically significant evidence of association with ADHD on the basis of the pooled odds ratio across studies: DRD4, DRD5, DAT, DBH, 5-HTT, HTR1B, and SNAP-25.

31
Q

Gizer et al. (2009)

A

Quantitative genetic studies (i.e., twin and adoption studies) suggest that genetic influences contribute substantially to the development of attention deficit hyperactivity disorder (ADHD). Over the past 15 years, considerable efforts have been made to identify genes involved in the etiology of this disorder resulting in a large and often conflicting literature of candidate gene associations for ADHD. The first aim of the present study was to conduct a comprehensive meta-analytic review of this literature to determine which candidate genes show consistent evidence of association with childhood ADHD across studies. The second aim was to test for heterogeneity across studies in the effect sizes for each candidate gene as its presence might suggest moderating variables that could explain inconsistent results. Significant associations were identified for several candidate genes including DAT1, DRD4, DRD5, 5HTT, HTR1B, and SNAP25. Further, significant heterogeneity was observed for the associations between ADHD and DAT1, DRD4, DRD5, DBH, ADRA2A, 5HTT, TPH2, MAOA, and SNAP25, suggesting that future studies should explore potential moderators of these associations (e.g., ADHD subtype diagnoses, gender, exposure to environmental risk factors). We conclude with a discussion of these findings in relation to emerging themes relevant to future studies of the genetics of ADHD.

32
Q

Valera et al. (2007)

A

Methods
We searched the MEDLINE and PsycINFO databases through January 2005. Studies must have been written in English, used magnetic resonance imaging, and presented the means and standard deviations of regions assessed. Data were extracted by one of the authors and verified independently by another author.

Results
Analyses were performed using STATA with metan, metabias, and metainf programs. A meta-analysis including all regions across all studies indicated global reductions for ADHD subjects compared with control subjects, standardized mean difference = .408, p < .001. Regions most frequently assessed and showing the largest differences included cerebellar regions, the splenium of the corpus callosum, total and right cerebral volume, and right caudate. Several frontal regions assessed in only two studies also showed large significant differences.

Conclusions
This meta-analysis provides a quantitative analysis of neuroanatomical abnormalities in ADHD and information that can be used to guide future studies.

33
Q

Faraone and Mick (2010)

A

screenshot

34
Q

Bobb et al. (2006)

A

Attention deficit hyperactivity disorder (ADHD) is highly heritable but is likely a complex disorder involving multiple genes of moderate effect (Smalley [1997: Am J Hum Genet 60:1276–1282]). Over 100 studies have examined the genetics of ADHD by linkage or association, though no article has presented a comprehensive overview of all published reports. We reviewed all ADHD studies, including 3 genome‐wide linkage studies, and association studies of 94 polymorphisms in 33 candidate genes. To simplify comparisons across heterogeneous articles, demographics and comorbidity were ignored; analyses of subtype and haplotypes were excluded; and only the most positive finding for each polymorphism in a study was reported. Thirty‐six percent of all findings were positive (P ≤ 0.05), 17% were trends (0.05  0.15). Studies utilizing dimensional measures of ADHD tended to result in higher rates of positive findings than those using categorical diagnoses (χ2 = 5.6, P = 0.018), and case‐control studies tended to result in higher rates of positive findings than family‐based studies (χ2 = 18.8, P 

35
Q

Zayats et al. (2019)

A

Attention-Deficit Hyperactivity Disorder (ADHD) is one of the most common and heritable childhood onset psychiatric conditions. The clinical phenotype is multidimensional with main symptoms being inattention and/or hyperactivity/impulsivity. As ADHD persists into adulthood (in up to ~80% of cases), some symptoms become more pronounced than others. Furthermore, the various aggregates of dimensions are associated with different clinical features (e.g. co-morbidities) and treatment outcomes of ADHD. So far, the biology behind such symptomatology of ADHD is far from understood. In this study, we aimed to explore the genetics of ADHD dimensions in children and their correlation with neuropsychiatric phenotypes in adulthood. The childhood sample consisted of 11,784 children from (1) Australia (N=4,000), (2) Canada (N=4,339) and (3) Norway (The Norwegian Mother Child Cohort (MoBa), N=3,445). ADHD dimensions were measured by the Strengths and Weaknesses of ADHD and Normal Behavior (SWAN) rating scale in Australia and Canada, and by Swanson, Nolan and Pelham, Teacher and Parent Rating Scale (SNAP) in Norway. The genetic similarity of SWAN and SNAP measures was assessed by LD regression. We also examined how genetic risk for ADHD symptoms correlated with neuropsychiatric phenotypes in adulthood, including schizophrenia, major depression disorder, bipolar disorder, Alzheimer’s disorder, subjective well-being, neuroticism and educational attainment. Overall, our preliminary results (N=3,445, SNAP data) suggest that the genetics of hyperactivity/impulsivity dimension in childhood show higher correlation with genetics of neuropsychiatric phenotypes in adulthood than that of childhood inattention, with strong contrasts between genetic correlations of hyperactivity/impulsivity and inattention with schizophrenia (h2=-0.115 and 0.0037), depressive symptoms (h2=0.483 and 0.278), subjective well-being (h2=-0.564 and -0.369), anxiety (h2=0.307 and 0.188) and Alzheimer’s disease (h2=0.280 and 0.076). We will present the results from the full sample(N=11,784). Further exploration of how ADHD dimensions in childhood relate/lead to neuropsychiatric pathology in adulthood will aid our understanding of biological processes underlying ADHD symptomatology and, potentially, lead to better diagnosis, treatment and prevention options for ADHD.

36
Q

Tarver et al. (2014)

A

Attention‐deficit hyperactivity disorder (ADHD) is a complex disorder that can affect individuals across the lifespan. It is associated with substantial heterogeneity in terms of aetiology, clinical presentation and treatment outcome and is the subject of extensive research. Because of this, it can be difficult for clinicians to stay up to date with the most relevant findings and know how best to respond to parents’ questions and concerns about the disorder and interventions. This is a narrative review that aims to summarize key findings from recent research into ADHD and its treatment that clinicians can share with families in order to increase their knowledge about ADHD and intervention options. ADHD develops as a result of complex interplay between interdependent genetic and non‐genetic factors. The disorder is associated with substantial impairments in functioning and poor long‐term outcomes. Pharmacological and non‐pharmacological treatment options are available for symptom management and to improve function, but functioning outcomes often fail to normalize in children with ADHD. Despite extensive advances in understanding this complex disorder, it is clear that there is still a long way to go. In particular, we address the need for future non‐pharmacological interventions to be more specifically targeted for ADHD symptoms and its commonly associated functioning deficits in order to ensure the best long‐term outcomes for children with ADHD

37
Q

Andersen et al. (2017)

A

The risk of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASD) may be influenced by environmental factors such as maternal obesity before pregnancy. Previous studies investigating those associations have found divergent results. We aim to investigate in a large birth cohort this association further in children with ADHD, ASD and comorbid ADHD and ASD. Our study population consisted of 81,892 mother–child pairs participating in the Danish National Birth Cohort (DNBC). Information about pre-pregnancy weight and height was collected in week 16 of pregnancy; the analysis was divided into groups based on BMI. Children with a clinical diagnosis of ADHD and/or ASD were identified in the Danish health registries at an average age of 13.3 years. Hazard ratios (HRs) were estimated using time-to-event analysis. Compared to normal weight mothers, the risk of having a child with ADHD was significantly increased if the mother was overweight (HR = 1.28 [95% CI 1.15;1.48]), obese (HR = 1.47 [95% CI 1.26;1.71]) or severely obese (HR = 1.95 [95% CI 1.58;2.40]). The same pattern was seen for the combined ADHD and ASD group. Regarding ASD, an increased risk was observed in underweight (HR = 1.30 [95% CI 1.01;1.69]) and obese (HR = 1.39 [95% CI 1.11;1.75]) mothers. Subgroup analysis revealed that the association in the ADHD group could mostly be attributable to the hyperactive group. Maternal obesity before pregnancy is a risk factor for ADHD in children. Maternal obesity as well as underweight may also be associated with an increased risk for ASD.

38
Q

Instanes et al. (2017)

A

Methods
We performed a population-based nested case-control study by linking data from longitudinal Norwegian registers. We included all individuals born during the period 1967–2008 and alive at record linkage (2012). Individuals receiving ADHD medication during the years 2004–2012 were defined as patients with ADHD (N = 47,944), and all remaining individuals (N = 2,274,713) were defined as control subjects. The associations between maternal diseases and ADHD in offspring were analyzed using logistic regression models.

Results
The following chronic diseases with immune components were related to ADHD in offspring: multiple sclerosis (adjusted odds ratio [OR] = 1.8; 95% confidence interval [CI] = 1.2–2.5), rheumatoid arthritis (adjusted OR = 1.7; 95% CI = 1.5–1.9), type 1 diabetes (adjusted OR = 1.6; 95% CI = 1.3–2.0), asthma (adjusted OR = 1.5; 95% CI = 1.4–1.6), and hypothyroidism (adjusted OR = 1.2; 95% CI = 1.1–1.4). In contrast, chronic hypertension and type 2 diabetes showed no significant associations. Estimates were almost unchanged with additional adjustment for parental ADHD, infant birth weight, and gestational age. Although point estimates for male and female offspring were different for some diseases (e.g., maternal asthma [adjusted OR = 1.7; 95% CI = 1.5–1.8 for female offspring and adjusted OR = 1.5; 95% CI = 1.4–1.6 for male offspring]), none of the associations differed significantly by offspring sex.

Conclusions
Several maternal somatic diseases with immune components were found to increase the risk of ADHD in offspring. The associations could involve several causal pathways, including common genetic predisposition and environmental factors, and increased insight into the mechanisms behind these relationships could enhance our understanding of the etiology of ADHD.

39
Q

Marceau et al. (2018)

A

We sought to test within- and between- family associations of smoking during pregnancy (SDP) and attention deficit-hyperactivity disorder (ADHD) symptoms using a structured interview based on the conventional Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) symptoms and the Strengths and Weaknesses of ADHD-Symptoms and Normal-Behavior (SWAN) scale, which is a population based measure that grew out of the notion that an ADHD diagnosis exists on the extreme end of a continuum of normative behaviors and includes both above- and below- average performance on attention and activity. We used a sibling-comparison approach in a sample of 173 families including siblings aged 7-16 years (52% male) drawn from the state of Missouri, USA, wherein mothers smoked during one pregnancy but not the other. There was a within-family effect of smoking during pregnancy on SWAN hyperactivity/impulsivity and SWAN total ADHD behaviors. The associations between SDP and DSM-IV-based ADHD symptom dimensions as well as SWAN inattention were explained by familial confounds. These findings suggest that SDP exerts a potentially causal effect on increased ADHD hyperactive/impulsive behaviors and that this SDP effect is best captured when hyperactivity/impulsivity is assessed more normatively across the population, rather than specifically assessing problematic behaviors via DSM symptoms. Thus, any potentially causal effect of SDP on ADHD symptom dimensions may be restricted to hyperactive/impulsive behaviors rather than inattention, and normative, non-DSM-IV based behavioral measures may provide a more sensitive test of mechanisms of SDP-ADHD symptom associations, particularly in non-clinical samples.

40
Q

Gustavson et al. (2017)

A

CONCLUSIONS: These results suggest that the association between maternal smoking during pregnancy and offspring ADHD is not due to causal intrauterine effects, but reflects unmeasured confounding.

41
Q

Yao (2017)

A

Methods

NHANES National Youth Fitness Survey (2012) was used in this study. Children on common ADHD medications were identified and formed the case group. The most commonly used stimulant medications include methylphenidate (Ritalin, Concerta), mixed amphetamine salts (Adderall), dextroamphetamine (Dexedrine), and lisdexamfetamine (Vyvanse). Non-stimulant medications with a specific indication for ADHD include atomoxetine (Strattera), guanfacine (Intuniv). Each case was matched to up to 5 controls based on sex, age, race, and low birth weight (< 5.5 lb). A conditional logistic regression was conducted among matched pairs to examine the impact of mother smoking status during pregnancy and ADHD. Odds ratios (OR) from the logistic regression, which is exp(coefficient), is used as a measure of association between exposure and outcome.

Results

A total of 60 ADHD cases were identified. The average age was 10.7 years; 75.0% male, 63.3% white and 13.3% with low birth weight. Only 57 cases were matched to a total of 238 controls. According to the conditional logistic regression, mother smoking during pregnancy was associated with increased risk for ADHD in children (Odds Ratio= 2.311, 95% Confidence Interval: 1.108-4.824, p= 0.026).

Conclusions

In this case-control study, mother smoking during pregnancy was significantly associated with ADHD in children. This is consistent with other publication with cohort study design. Additional efforts should be made to improve the awareness of the increased risk of ADHD in children associated with mother smoking during pregnancy.

42
Q

Perapoch et al. (2019)

A

Conclusion: Being born preterm is associated with a risk of developing ADHD, also in late preterm children (35-36 gw). Attention when taking care of these infants regarding their mental health must be made.

43
Q

Johnston and Mash (2001)

A

This review integrates and critically evaluates what is known about family characteristics associated with childhood Attention-Deficit/Hyperactivity Disorder (ADHD). Evidence suggests that the presence of ADHD in children is associated to varying degrees with disturbances in family and marital functioning, disrupted parent–child relationships, specific patterns of parental cognitions about child behavior and reduced parenting self-efficacy, and increased levels of parenting stress and parental psychopathology, particularly when ADHD is comorbid with conduct problems. However, the review reveals that little is known about the developmental mechanisms that underlie these associations, or the pathways through which child and family characteristics transact to exert their influences over time. In addition, the influence of factors such as gender, culture, and ADHD subtype on the association between ADHD and family factors remains largely unknown. We conclude with recommendations regarding the necessity for research that will inform a developmental psychopathology perspective of ADHD.

44
Q

Joseph et al. (2018)

A

Despite high heritability, no research has followed children with ADHD to parenthood to study their offspring and parenting behaviors. Given greater prevalence of ADHD in males and lack of research involving fathers, this study evaluated offspring of fathers with and without ADHD histories for ADHD and disruptive behavior and compared fathers’ parenting behaviors. Male fathers (N = 29) from the Pittsburgh ADHD Longitudinal Study (PALS) participated with their preschool-aged offspring. Fathers completed self-reported measures, and father-child dyads completed an interaction task. ADHD offspring had elevated ADHD symptoms and behavior dysregulation. All fathers displayed positive parenting. ADHD fathers reported lower supportive responses to their child’s negative emotions than comparison fathers, yet rated their parenting as more efficacious. ADHD offspring were distinguishable as early as age 3; thus, earlier diagnosis and intervention may be feasible for this at-risk population. Future research should investigate the acceptability and efficacy of parent training for fathers with ADHD.

45
Q

Willoughby et al. (2019)

A

This study used repeated measures data to identify developmental profiles of elevated risk for ADHD (i.e., six or more inattentive and/or hyperactive-impulsive symptoms), with an interest in the age at which ADHD risk first emerged. Risk factors that were measured across the first 3 years of life were used to predict profile membership. Participants included 1,173 children who were drawn from the Family Life Project, an ongoing longitudinal study of children’s development in low-income, nonmetropolitan communities. Four heuristic profiles of ADHD risk were identified. Approximately two thirds of children never exhibited elevated risk for ADHD. The remaining children were characterized by early childhood onset and persistent risk (5%), early childhood limited risk (10%), and middle childhood onset risk (19%). Pregnancy and delivery complications and harsh-intrusive caregiving behaviors operated as general risk for all ADHD profiles. Parental history of ADHD was uniquely predictive of early onset and persistent ADHD risk, and low primary caregiver education was uniquely predictive of early childhood limited ADHD risk. Results are discussed with respect to how changes to the age of onset criterion for ADHD in DSM5 may affect etiological research and the need for developmental models of ADHD that inform ADHD symptom persistence and desistance.

46
Q

Wiener et al. (2015)

A

This study examined parenting stress among parents of adolescents with Attention-Deficit Hyperactivity Disorder (ADHD). The sample comprised 138 adolescents (84 ADHD, 52 boys, 32 girls; 54 non-ADHD, 24 boys, 30 girls) age 13 to 18 and their parents. Mothers (n = 135) and fathers (n = 98) of participating teens completed the Stress Index for Parents of Adolescents. Mothers and fathers of adolescents with ADHD reported more stress than parents of adolescents without ADHD with regard to their children’s challenging behaviors (Adolescent domain stress). Mothers of adolescents with ADHD also reported that they experienced elevated levels of stress in terms of role restrictions, feelings of social alienation, conflict with their partner, feelings of guilt and incompetence (Parent domain stress), and relationship with their children (Adolescent-Parent Relationship domain stress; APR). The extent to which clinical levels of adolescent Oppositional Defiant Disorder (ODD) symptoms or externalizing behavior in general were associated with parenting stress depended on the rater of these behaviors. Parenting stress was associated with higher levels of ODD and other externalizing behaviors when these behaviors were rated by parents but not when they were rated by teachers. In addition, over and above adolescent ADHD classification, mothers’ self-reported ADHD symptoms were associated with higher parenting stress in the Adolescent and Parent domains, and fathers’ self-reported ADHD symptoms were associated with lower APR stress. The results suggest directions that should be considered for addressing parenting stress when designing interventions for families of adolescents with ADHD.

47
Q

Schroeder and Kelley (2009)

A

children had greater problems with behavioural control

family environments less organised and higher in familia’s conflict

however family environment was not correlated with behavioural control

In general, aspects of the family environment and parental limit setting appear to be associated with the development of executive functions in children not diagnosed with ADHD; however, family environment and parenting practices were not associated with executive functions in children diagnosed with ADHD.

48
Q

Bateman et al. (2004)

A

Methods: A sample of 1873 children were screened in their fourth year for the presence of hyperactivity at baseline (HA), of whom 1246 had skin prick tests to identify atopy (AT). Children were selected to form the following groups: HA/AT, not-HA/AT, HA/not-AT, and not-HA/not-AT (n = 277). After baseline assessment, children were subjected to a diet eliminating artificial colourings and benzoate preservatives for one week; in the subsequent three week within subject double blind crossover study they received, in random order, periods of dietary challenge with a drink containing artificial colourings (20 mg daily) and sodium benzoate (45 mg daily) (active period), or a placebo mixture, supplementary to their diet. Behaviour was assessed by a tester blind to dietary status and by parents’ ratings.

Results: There were significant reductions in hyperactive behaviour during the withdrawal phase. Furthermore, there were significantly greater increases in hyperactive behaviour during the active than the placebo period based on parental reports. These effects were not influenced by the presence or absence of hyperactivity, nor by the presence or absence of atopy. There were no significant differences detected based on objective testing in the clinic.

Conclusions: There is a general adverse effect of artificial food colouring and benzoate preservatives on the behaviour of 3 year old children which is detectable by parents but not by a simple clinic assessment. Subgroups are not made more vulnerable to this effect by their prior levels of hyperactivity or by atopy.

49
Q

Holton et al. (2018)

A

Methods: Children, 7–12 years old, with (n = 23) and without (n = 22) ADHD, and college students, 18–25 years old, with (n = 21) and without (n = 30) ADHD comprised the samples. Children’s dietary intake was assessed by a registered dietitian using 24-hour recalls over 3 days. College students kept a detailed food record over three days. Dietary information for both groups was entered into the Nutrition Data Systems for Research database, and output was analyzed using SAS 9.4. Nutrient analyses included the Healthy Eating Index-2010, Micronutrient Index (as a measure of overall micronutrient intake), and individual amino acids necessary for neurotransmission. Logistic regression was used to model the association of nutrient intake with ADHD. Models were adjusted for age, sex, IQ (or GPA), and energy intake (or total protein intake) as appropriate. Significance was evaluated at P = 0.05, and using the Benjamini–Hochberg corrected P-value for multiple comparisons.

Results: No evidence existed for reduced nutrient intake among those with ADHD compared to controls in either age group. Across both groups, inadequate intakes of vitamin D and potassium were reported in 95% of participants. Children largely met nutrient intake guidelines, while college students failed to meet these guidelines for nine nutrients. In regards to amino acid intake in children, an increased likelihood of having ADHD was associated with higher consumption of aspartate, OR = 12.61 (P = 0.01) and glycine OR = 11.60 (P = 0.05); and a reduced likelihood of ADHD with higher intakes of glutamate, OR = 0.34 (P = 0.03). Among young adults, none of the amino acids were significantly associated with ADHD, though glycine and tryptophan approached significance.

Discussion: Results fail to support the hypothesis that ADHD is driven solely by dietary micronutrient inadequacy. However, amino acids associated with neurotransmission, specifically those affecting glutamatergic neurotransmission, differed by ADHD status in children. Amino acids did not reliably vary among college students. Future larger scale studies are needed to further examine whether or not dietary intake of amino acids may be a modulating factor in ADHD.

50
Q

Del-Ponte et al. (2019) - sugar

A

The sucrose consumption was associated with the prevalence of ADHD only among boys at 6 years of age.

That persistence of high consumption or an increase in sugar consumption between 6 and 11 years of age was not associated with higher incidence of ADHD between 6 and 11 years of age.

The higher sugar consumption by children with ADHD is possibly a consequence rather than a determinant of the disorder.

51
Q

Del-Ponte et al, (2019) - general diet

A

The meta-analysis suggests that a unhealthy diet can increase the risk of ADHD, whereas a healthy diet, would protect against these outcomes.

The unhealthy dietary pattern, characterized by the consumption of saturated fat and refined sugar was associated to the risk of hyperactivity or ADHD occurrence.

The healthy patterns, characterized by the consumption of fruits, vegetables and whole grains showed a protective effect against hyperactivity or ADHD.

52
Q

Rytter et al. (2014)

A

Background: Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent psychiatric conditions in childhood. Dietary changes have been suggested as a way of reducing ADHD symptoms. Aims: To provide an overview of the evidence available on dietary interventions in children with ADHD, a systematic review was carried out of all dietary intervention studies in children with ADHD. Methods: Relevant databases were searched in October 2011, with an update search in March 2013. The studies included describe diet interventions in children with ADHD or equivalent diagnoses measuring possible changes in core ADHD symptoms: inattention, hyperactivity and impulsivity. Results: A total of 52 studies were identified, some investigating whether ADHD symptoms can improve by avoiding certain food elements (20 studies), and some whether certain food elements may reduce ADHD symptoms (32 studies). Conclusion: Elimination diets and fish oil supplementation seem to be the most promising dietary interventions for a reduction in ADHD symptoms in children. However, the studies on both treatments have shortcomings, and more thorough investigations will be necessary to decide whether they are recommendable as part of ADHD treatment

53
Q

Cagigal et al. (2019)

A

Method: The authors conducted a classical review on the current treatment recommended in individuals with ADHD diagnosis, their dietary patterns, as well as dietary factors possibly implicated in the etiology and treatment of this disorder. An extensive bibliographic research was carried out in the databases PubMed, The Cochrane Library and the National Guideline Clearinghouse.

Discussion: The most common dietary interventions in the case of ADHD are food supplementation diets (e.g. PUFAs, vitamins) and elimination diets. Supplementation with omega-3 PUFAs lacks further studies that can validate them as an effective therapeutic approach in this disorder. Also, regarding vitamin supplementation, studies are not consistent as to their role in the etiology of ADHD. Elimination diets are unclear as to the benefits provided in individuals with ADHD. Children with ADHD are less likely to engage in healthy lifestyle behaviors than non-ADHD youth.

Conclusion: There is no clear evidence that supports dietary interventions for the treatment of ADHD. The effects of unhealthy diet patterns in ADHD individuals are not yet fully understood and, like the general population, children with ADHD may benefit from a healthy lifestyle

54
Q

Sonouga-Barke and Castellanous (2007)

A

In traditional accounts, fluctuations in sustained and focused attention and associated attentional lapses during task performance are regarded as the result of failures of top-down and effortful higher order processes. The current paper reviews an alternative hypothesis: that spontaneous patterns of very low frequency coherence within a specific brain network (‘default-mode network’) thought to support a pattern of generalized task-non-specific cognition during rest, can persist or intrude into periods of active task-specific processing, producing periodic fluctuations in attention that compete with goal-directed activity. We review recent studies supporting the existence of the resting state default network, examine the mechanism underpinning it, describe the consequent temporally distinctive effects on cognition and behaviour of default-mode interference into active processing periods, and suggest some factors that might predispose to it. Finally, we explore the putative role of default-mode interference as a cause of performance variability in attention deficit/hyperactivity disorder.

55
Q

Cai et al. (2019)

A

Attention-deficit hyperactivity disorder (ADHD) is associated with pervasive impairments in attention and cognitive control. Although brain circuits underlying these impairments have been extensively investigated with resting-state fMRI, little is known about task-evoked functional brain circuits and their relation to cognitive control deficits and inattention symptoms in children with ADHD. Children with ADHD and age, gender and head motion matched typically developing (TD) children completed a Go/NoGo fMRI task. We used multivariate and dimensional analyses to investigate impairments in two core cognitive control systems: (i) cingulo-opercular “salience” network (SN) anchored in the right anterior insula, dorsal anterior cingulate cortex (rdACC), and ventrolateral prefrontal cortex (rVLPFC) and (ii) dorsal frontoparietal “central executive” (FPN) network anchored in right dorsolateral prefrontal cortex (rDLPFC) and posterior parietal cortex (rPPC). We found that multivariate patterns of task-evoked effective connectivity between brain regions in SN and FPN distinguished the ADHD and TD groups, with rDLPFC–rPPC connectivity emerging as the most distinguishing link. Task-evoked rdACC–rVLPFC connectivity was positively correlated with NoGo accuracy, and negatively correlated with severity of inattention symptoms. Brain–behavior relationships were robust against potential age, gender, and head motion confounds. Our findings highlight aberrancies in task-evoked modulation of SN and FPN connectivity in children with ADHD. Crucially, cingulo-frontal connectivity was a common locus of deficits in cognitive control and clinical measures of inattention symptoms. Our study provides insights into a parsimonious systems neuroscience model of cognitive control deficits in ADHD, and suggests specific circuit biomarkers for predicting treatment outcomes in childhood ADHD.

56
Q

Hilger and Fiebach (2019)

A

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders with significant and often lifelong effects on social, emotional, and cognitive functioning. Influential neurocognitive models of ADHD link behavioral symptoms to altered connections between and within functional brain networks. Here, we investigate whether network-based theories of ADHD can be generalized to understanding variations in ADHD-related behaviors within the normal (i.e., clinically unaffected) adult population. In a large and representative sample, self-rated presence of ADHD symptoms varied widely; only 8 out of 291 participants scored in the clinical range. Subject-specific brain network graphs were modeled from functional MRI resting-state data and revealed significant associations between (nonclinical) ADHD symptoms and region-specific profiles of between-module and within-module connectivity. Effects were located in brain regions associated with multiple neuronal systems including the default-mode network, the salience network, and the central executive system. Our results are consistent with network perspectives of ADHD and provide further evidence for the relevance of an appropriate information transfer between task-negative (default-mode) and task-positive brain regions. More generally, our findings support a dimensional conceptualization of ADHD and contribute to a growing understanding of cognition as an emerging property of functional brain networks.

57
Q

Mills et al. (2018)

A

ADHD children had reduced connectivity between task positive and negative networks in the form of attention and detection tasks

58
Q

Icer et al. (2019)

A

The aim of this study was to investigate changes of functional connectivity (FC) in resting state networks (RSNs) in medication-naive children with attention-deficit/hyperactivity disorder (ADHD). Twenty children with a diagnosis of ADHD (11.8 +/- 2.29 years; 16 boys) and 20 age-matched typically developing (TD) children (13 +/- 1.78 years; 10 boys) were included. It was found that brain FC differences in children with ADHD are not only in the well known RSNs such as default mode, visual, sensory motor, attentional, frontal, central executive, and frontal networks but also involve interaction among whole brain functional networks. In addition, basal ganglia and cerebellum networks which later gained importance were examined in this study. All RSNs has been shown significant differences in special regions which belongs related RSN. The highest positive (HPC) and negative (HNC) correlation were calculated between 14 independent components including 11 different RSNs. We observed different FC changes (decreased/increased) according to the RSNs between ADHD and control children. The HPC was defined between the visual and cerebellum network in ADHD children and between the dorsal attentional network and sensory motor network in TD children. Also, the HNC was detected between the visual and basal ganglia network in both groups. Investigating intra and inter network FC could provide a framework to better understand the neural basis that underlies core symptom dimensions in ADHD.

59
Q

Sciberras et al. (2017)

A

While it is well accepted that attention-deficit/hyperactivity disorder (ADHD) is a highly heritable disorder, not all of the risk is genetic. It is estimated that between 10 and 40% of the variance associated with ADHD is likely to be accounted for by environmental factors. There is considerable interest in the role that the prenatal environment might play in the development of ADHD with previous reviews concluding that despite demonstration of associations between prenatal risk factors (e.g. prematurity, maternal smoking during pregnancy) and ADHD, there remains insufficient evidence to support a definite causal relationship. This article provides an update of research investigating the relationship between prenatal risk factors and ADHD published over the past 3 years. Recently, several epidemiological and data linkage studies have made substantial contributions to our understanding of this relationship. In particular, these studies have started to account for some of the genetic and familial confounds that, when taken into account, throw several established findings into doubt. None of the proposed prenatal risk factors can be confirmed as causal for ADHD, and the stronger the study design, the less likely it is to support an association. We need a new benchmark for studies investigating the etiology of ADHD whereby there is an expectation not only that data will be collected prospectively but also that the design allows the broad range of genetic and familial factors to be accounted for.

60
Q

Sharma and Couture (2014)

A

Objective: To review the pathophysiology, etiology, and treatment of attention-deficit hyperactivity disorder (ADHD). Data Sources and Data Extraction: A literature search was conducted in PubMed and EMBASE using the terms attention deficit hyperactive disorder, ADHD, pathophysiology, etiology, and neurobiology. Limits applied were the following: published in the past 10 years (January 2003 to August 2013), humans, review, meta-analysis, and English language. These yielded 63 articles in PubMed and 74 in EMBASE. After removing duplicate/irrelevant articles, 86 articles and their relevant reference citations were reviewed. Data Synthesis: ADHD is a neurological disorder that affects children, but symptoms may persist into adulthood. Individuals suffering from this disorder exhibit hyperactivity, inattention, impulsivity, and problems in social interaction and academic performance. Medications used to treat ADHD such as methylphenidate, amphetamine, and atomoxetine indicate a dopamine/norepinephrine deficit as the neurochemical basis of ADHD, but the etiology is more complex. Moreover, these agents have poor adverse effect profiles and a multitude of drug interactions. Because these drugs are also dispensed to adults who may have concomitant conditions or medications, a pharmacist needs to be aware of these adverse events and drug interactions. This review, therefore, focuses on the pathophysiology, etiology, and treatment of ADHD and details the adverse effects and drug interaction profiles of the drugs used to treat it. Conclusions: Published research shows the benefit of drug therapy for ADHD in children, but given the poor adverse effect and drug interaction profiles, these must be dispensed with caution.

61
Q

Barkley (1997)

A

Attention deficit hyperactivity disorder (ADHD) comprises a deficit in behavioral inhibition. A theoretical model is constructed that links inhibition to 4 executive neuropsychological functions that appear to depend on it for their effective execution: (a) working memory, (b) self-regulation of affect–motivation–arousal, (c) internalization of speech, and (d) reconstitution (behavioral analysis and synthesis). Extended to ADHD, the model predicts that ADHD should be associated with secondary impairments in these 4 executive abilities and the motor control they afford. The author reviews evidence for each of these domains of functioning and finds it to be strongest for deficits in behavioral inhibitions, working memory, regulation of motivation, and motor control in those with ADHD. Although the model is promising as a potential theory of self-control and ADHD, far more research is required to evaluate its merits and the many predictions it makes about ADHD.

62
Q

Fosco et al. (2018)

A

Inhibition is a key neurocognitive domain in ADHD that is commonly assessed with the stop-signal task. The stop-signal involves both “go” and “stop” trials; previous research indicates that response times are reliably slower to “go” trials during tasks with vs. without intermittent “stop” trials. However, it is unclear whether this pattern reflects deliberate slowing to maximize inhibitory success (performance adjustment hypothesis) and/or disrupted bottom-up information processing due to increased cognitive demands (dual-task hypothesis). Given the centrality of “go” responding for estimating children’s inhibitory speed, finding that children with ADHD slow differently –or for different reasons– has the potential to inform cognitive and self-regulatory theories of ADHD. The current study used a carefully-controlled experimental design to assess the mechanisms underlying stop signal-related slowing in ADHD. Children ages 8-13 with (n = 81) and without ADHD (n = 63) completed the stop-signal task and a control task that differed only in the presence/absence of “stop” trials. Using drift-diffusion modeling, Bayesian repeated-measures ANOVAs revealed a pattern consistent with the performance adjustment hypothesis, such that children adopted more cautious response strategies (BF10 = 6221.78; d = 0.38) but did not show changes in processing speed (BF01 = 3.08; d = 0.12) or encoding/motor speed (BF01 = 5.73; d = 0.07) when inhibition demands were introduced. Importantly, the ADHD/Non-ADHD groups showed equivalent effects of intermittent “stop” trials (BF01 = 4.30-5.56). These findings suggest intact self-regulation/performance monitoring in the context of adapting to increased inhibitory demands in ADHD, which has important implications for the continued isolation of potential mechanisms associated with ADHD symptoms and impairment.

63
Q

Bitsakou et al, (2008)

A

Methods. Seventy-seven children and adolescents with ADHD and 50 non-ADHD controls completed three inhibitory tasks, a simple two choice RT task (2CR) and an IQ assessment.

Results. ADHD was moderately associated with deficits on all tasks (effect sizes d=0.5–0.9). Deficits were equally marked in childhood and adolescence. Inhibitory deficits were not associated with IQ and, although reduced substantially, remained significant after performance on a simple reaction time task was controlled for statistically.

Discussion. In highlighting the significant, but limited, role of inhibitory deficits in ADHD, these results are consistent with recent accounts that emphasize the neuropsychological heterogeneity of this condition.

64
Q

Sonuga-Barke et al. (2010)

A

Method
Nine tasks designed to tap three domains (inhibitory control, delay aversion and temporal processing) were administered to ADHD probands (n=71; ages 6 to 17 years), their siblings (n=71; 65 unaffected by ADHD) and a group of non-ADHD controls (n=50). IQ and working memory were measured.

Results
Temporal processing, inhibitory control and delay-related deficits represented independent neuropsychological components. ADHD children differed from controls on all factors. For ADHD patients, the co-occurrence of inhibitory, temporal processing and delay-related deficits was no greater than expected by chance with substantial groups of patients showing only one problem. Domain-specific patterns of familial co-segregation provided evidence for the validity of neuropsychological subgroupings.

Conclusion
The current results illustrate the neuropsychological heterogeneity in ADHD and initial support for a triple pathway model. The findings need to be replicated in larger samples.

65
Q

Lipszyc and Schachar (2010)

A

The Stop Signal Task (SST) is a measure that has been used widely to assess response inhibition. We conducted a meta-analysis of studies that examined SST performance in patients with various psychiatric disorders to determine the magnitude and generality of deficient inhibition. A five-item instrument was used to assess the methodological quality of studies. We found medium deficits in stop signal reaction time (SSRT), reflecting the speed of the inhibitory process, for attention-deficit hyperactivity disorder (ADHD) (g = 0.62), obsessive compulsive disorder (OCD) (g = 0.77) and schizophrenia (SCZ) (g = 0.69). SSRT was less impaired or normal for anxiety disorder (ANX), autism, major depressive disorder (MDD), oppositional defiant disorder/conduct disorder (ODD/CD), pathological gambling, reading disability (RD), substance dependence, and Tourette syndrome. We observed a large SSRT deficit for comorbid ADHD + RD (g = 0.82). SSRT was less than moderately impaired for ADHD + ANX and ADHD + ODD/CD. Study quality did not significantly affect SSRT across ADHD studies. This confirms an inhibition deficit in ADHD, and suggests that comorbid ADHD has different effects on inhibition in patients with ANX, ODD/CD, and RD. Further studies are needed to firmly establish an inhibition deficit in OCD and SCZ. (JINS, 2010, 16, 1064–1076.)

66
Q

Sonuga-Barke et al. (1992)

A

Two experiments arc reported in which hyperactive and control children repeatedly chose between small immediate and large delayed it‐wards. In experiment 1, the best choice option was manipulated by varying levels of delay after reward delivery. In experiment 2 it was manipulated by changing the economic constraint (10 minutes or 20 trials). Both groups were equally efficient at earning points under most conditions, but hyperactive children exhibited a maladaptive preference for the small reward under the trials constraint. The results suggest that hyperactive children were more concerned to reduce overall delay levels than either to maximize reward amount or immediacy.

67
Q

Mies et al. (2019)

A

Adolescents with attention-deficit/hyperactivity disorder (ADHD) are known to have stronger preferences for smaller immediate rewards over larger delayed rewards in delay discounting tasks than their peers, which has been argued to reflect delay aversion. Here, participants performed a delay discounting task with gains and losses. In this latter condition, participants were asked whether they were willing to wait in order to lose less money. Following the core assumption of the delay aversion model that individuals with ADHD have a general aversion to delay, one would predict adolescents with ADHD to avoid waiting in both conditions. Adolescents (12–17 years) with ADHD (n = 29) and controls (n = 28) made choices between smaller immediate and larger delayed gains, and between larger immediate and smaller delayed losses. All delays (5–25 s) and gains/losses (2–10 cents) were experienced. In addition to an area under the curve approach, a mixed-model analysis was conducted to disentangle the contributions of delay duration and immediate gain/delayed loss amount to choice. The ADHD group chose the immediate option more often than controls in the gain condition, but not in the loss condition. The contribution of delay duration to immediate choices was stronger for the ADHD group than the control group in the gain condition only. In addition, the ADHD group scored higher on self-reported delay aversion, and delay aversion was associated with delay sensitivity in the gain condition, but not in the loss condition. In sum, we found no clear evidence for a general aversion to delay in adolescents with ADHD.

68
Q

Marx et al. (2019)

A

Objective: Impulsive choices can lead to sub-optimal decision making, a tendency which is especially marked in individuals with ADHD. We compared two different paradigms assessing impulsive choice, the simple choice paradigm (SCP) and the temporal discounting paradigm (TDP). Methods: Random effects meta-analyses on thirty-seven group comparisons (22 SCP; 15 TDP) consisting of 3.763 subjects (53% ADHD). Results: Small to medium effect sizes emerged for both paradigms, confirming that subjects with ADHD choose small immediate over large delayed rewards more frequently than controls. Moderation analyses show that offering real rewards in the SCP almost doubled the odds ratio for subjects with ADHD. Conclusion: We suggest that a stronger than normal aversion towards delay interacts with a demotivating effect of hypothetical rewards, both factors promoting impulsive choice in subjects with ADHD. Further, we suggest the SCP as the paradigm of choice due to its larger ecological validity, contextual sensitivity, and reliability.

69
Q

Bitsakou et al. (2009)

A

Method
Seventy seven male and female individuals (age range 6–17) with a research diagnosis combined type ADHD, 65 of their siblings unaffected by ADHD and 50 non-ADHD controls completed three delay tasks.

Results
As predicted the size of the correlation between tasks was small but a common latent component was apparent. Children with ADHD differed from controls on all tasks (d = .4–.7) and on an overall DAv index (d = .9): The battery as a whole demonstrated moderate sensitivity and specificity. In general, deficits were equally marked in childhood and adolescence and were independent of comorbid ODD. IQ moderated the effect on the MIDA. Scores on the DAv factor co-segregated within ADHD families.

Discussion
There is value in exploring the broader DAv phenotype in ADHD. The results illustrate the power of multivariate approaches to endophenotypes. By highlighting the significant, but limited, role of DAv in ADHD these results are consistent with recent accounts that emphasize neuropsychological heterogeneity.

70
Q

Blume et a. (2019)

A

Impulsive behaviours occurring as a central deficit in connection with attention-deficit/hyperactivity disorder (ADHD) are associated with social and academic impairment in children. Whereas impulsivity was shown to be related to both delay aversion and deficient timing skills, the mutual relation between the latter two has hardly been investigated. The present study therefore examined the interplay of delay aversion, timing skills, and impulsivity in a sample of eighty-eight children aged between seven and fourteen, twenty-one of them diagnosed with ADHD. Children participated in a delay aversion and a tapping task, while parents reported about their impulsiveness. The results showed that both delay aversion and deficient timing skills were related to impulsivity. Contrasting prior assumptions, delay aversion and timing skills were also shown to be related, even when controlling for impulsivity. Implications for interventions aiming to reduce children’s impulsivity as well as methodological considerations regarding whether to view ADHD as a category or a continuum are discussed

71
Q

Steele et al. (2018)

A

The nucleus accumbens core (NAc) has long been recognized as an important contributor to the computation of reward value that is critical for impulsive choice behavior. Impulsive choice refers to choosing a smaller-sooner (SS) over a larger-later (LL) reward when the LL is more optimal in terms of the rate of reward delivery. Two experiments examined the role of the NAc in impulsive choice and its component processes of delay and magnitude processing. Experiment 1 delivered an impulsive choice task with manipulations of LL reward magnitude, followed by a reward magnitude discrimination task. Experiment 2 tested impulsive choice under manipulations of LL delay, followed by temporal bisection and progressive interval tasks. NAc lesions, in comparison to sham control lesions, produced suboptimal preferences that resulted in lower reward earning rates, and led to reduced sensitivity to magnitude and delay within the impulsive choice task. The secondary tasks revealed intact reward magnitude and delay discrimination abilities, but the lesion rats persisted in responding more as the progressive interval increased during the session. The results suggest that the NAc is most critical for demonstrating good sensitivity to magnitude and delay, and adjusting behavior accordingly. Ultimately, the NAc lesions induced suboptimal choice behavior rather than simply promoting impulsive choice, suggesting that an intact NAc is necessary for optimal decision making.

72
Q

Sonuga-Barke (2002)

A

Psychological accounts have characterised attention-deficit/hyperactivity disorder (AD/HD) as either a neuro-cognitive disorder of regulation or a motivational style. Poor inhibitory control is thought to underpin AD/HD children’s dysregulation while delay aversion is a dominant characteristic of their motivational style. A recent ‘head to head’ study of these two accounts suggest that delay aversion and poor inhibitory control are independent co-existing characteristics of AD/HD (combined type). In the present paper we build on these findings to propose a dual pathway model of AD/HD that recognises two quite distinct sub-types of the disorder. In one AD/HD is the result of the dysregulation of action and thought resulting from poor inhibitory control associated with the meso-cortical branch of the dopamine system projecting in the cortical control centres (e.g. pre-frontal cortex). In the other AD/HD is a motivational style characterised by an altered delay of reward gradient linked to the meso-limbic dopamine branch associated with the reward circuits (e.g. nucleus accumbens). The two pathways are further distinguished at the levels of symptoms, cognitive and motivation profiles and genetic and non-genetic origins.

73
Q

Tamm et al. (2019)

A

This goal of this study was to assess the initial feasibility and efficacy of a play-based intervention targeting executive functions (EF) and parent–child relationships in preschoolers compared with an active control group. Preschoolers with EF deficits (M age = 3.7 ± 0.47, predominantly White boys) and their parents were randomized to intervention (n = 36) or active control (n = 32) conditions. Child performance on EF tasks, parent and masked teacher ratings of EF and behavior, and masked clinician ratings of severity were collected at baseline and at 3 and 6 months postbaseline. Partial eta-squared effect sizes at .02 or higher comparing performance across the two groups was considered evidence of meaningful, albeit small, intervention effects. Intervention effects were observed for parent ratings of inattention, hyperactivity/impulsivity, and number/severity of problems experienced in various home situations, teacher ratings of severity of problems in various school situations, parent and teacher ratings of overall impairment, and clinician ratings of impairment. Intervention effects for functional improvements were maintained at the 6-month follow-up. No effect of the intervention was observed on the objective EF measures, although parent ratings of emotional control were improved for children in the intervention group. An intervention utilizing play-based activities targeting EF, when administered in a structured way by parents, is a promising approach for improving behavior in preschoolers with self-regulation deficits. More work is needed to investigate potential impact on EF and to disentangle mechanisms of action. It may be that the intervention’s focus on the structure and quality of parent–child interactions is a mediator of outcomes, rather than improved EFs.

74
Q

Sagvolden et al. (2005)

A

attention-deficit/hyperactivity disorder (adhd) is currently defined as a cognitive/behavioral developmental disorder where all clinical criteria are behavioral. inattentiveness, overactivity, and impulsiveness are presently regarded as the main clinical symptoms. the dynamic developmental behavioral theory is based on the hypothesis that altered dopaminergic function plays a pivotal role by failing to modulate nondopaminergic (primarily glutamate and gaba) signal transmission appropriately. a hypofunctioning mesolimbic dopamine branch produces altered reinforcement of behavior and deficient extinction of previously reinforced behavior. this gives rise to delay aversion, development of hyperactivity in novel situations, impulsiveness, deficient sustained attention, increased behavioral variability, and failure to “inhibit” responses (“disinhibition”).

a hypofunctioning mesocortical dopamine branch will cause attention response deficiencies (deficient orienting responses, impaired saccadic eye movements, and poorer attention responses toward a target) and poor behavioral planning (poor executive functions). a hypofunctioning nigrostriatal dopamine branch will cause impaired modulation of motor functions and deficient nondeclarative habit learning and memory. these impairments will give rise to apparent developmental delay, clumsiness, neurological “soft signs,” and a “failure to inhibit” responses when quick reactions are required.

hypofunctioning dopamine branches represent the main individual predispositions in the present theory. the theory predicts that behavior and symptoms in adhd result from the interplay between individual predispositions and the surroundings. the exact adhd symptoms at a particular time in life will vary and be influenced by factors having positive or negative effects on symptom development. altered or deficient learning and motor functions will produce special needs for optimal parenting and societal styles. medication will to some degree normalize the underlying dopamine dysfunction and reduce the special needs of these children. the theory describes how individual predispositions interact with these conditions to produce behavioral, emotional, and cognitive effects that can turn into relatively stable behavioral patterns.