Interventions Flashcards
best to worst types of research ev
- meta-analysis
- systematic reviews
- RCTs
- cohort studies
- case-control studies
- case reports
- expert opinions
- testimonials
gold standard for systematic review
cochrane review
ways to evaluate interventions
- effect sizes
- bias
selection bias
- difference between baseline characteristics of the groups that are compared
- avoid by randomisation
performance bias
- difference between groups in the care that is provided
- avoid by double-blinding
detection bias
- diffs between groups in how outcomes are determined
- avoid by outcome assessor blinding
attrition bias
- diffs between groups in withdrawals from a study, either due to exclusions or attritions
- difficult to control for
reporting bias
- diffs between reported & reported findings
- avoid with pre-specified outcome measures
exercise & ADHD
- growing body of research investigating impact of diff types of exercise on ADHD
- yoga, playground games, exergaming
yoga as an intervention
jensen & kenny (2004)
- 8-13yo boys with ADHD
- treatment - 20 weekly 1hr sessions of yoga
- control - monthly 1hr sessions of cooperative games & activities
- unclear on all types of bias
playground games as an intervention
hoza et al. (2014)
- 4-9yos neurotypical, at risk of ADHD
- treatment - 12 weeks of games in playground
- control - 12 weeks of art in classroom
- low performance and attrition bias
- unclear on other types of bias
exergaming as an intervention
benzing & schmidt (2019)
- 8-12yos with ADHD
- treatment - 8 weeks of shape up (xbox kinect)
- control - waiting list control
- low selection and performance bias
- unclear detection and attrition bias
meta-analysis of exercise interventions
sun et al. (2022)
- 15 RCTs of exercise interventions of ADHD
- used cochrane collaboration tool to establish bias
- 1 out of 15 high quality/low risk of bias
- some ev that physical ev can improve inattentive symptoms, EFs & motor skills in children with ADHD
- heterogeneity in findings may in part be due to diffs in intervention duration & freq
- very few studies were at low risk of bias. for many studies there was insufficient info provided about allocation & blinding procedures
medications
- stimulants e.g. methylphenidate
- non-stimulants
- biederman & faraone (2005) - stimulant medication has a large effect size than non-stimulant medication
effect of medication on cognition
- medication improves ADHD symptoms but does it also improve cog performance?
- can help us to understand causal pathways in ADHD
tamminga et al. (2016)
medication and executive functions
- meta-analysis of 50 studies of effects of MPH on response inhibition, WM & sustained attention
- medium effect sizes for response inhibition & sustained attention
- low effect size for WM
- MPH does tend to improve EFs but only certain aspects
pietrzak et al. (2006)
medication and EF
- MPH modulate striatal activity & –> motor & cog processes mediated by the striatum
- reasons for inconsistencies between studies
- multiple phenotypes
- variability in medication response
- repeated assessments (practice effects)
- limitations - low power, only gave one size dose
coghill et al. (2007)
medication and EF
- placebo-controlled, double blinded, randomised, crossover trial
- predictions: chronic exposure to MPH will enhance performance on executive tasks
- didnt find this - if EF difficulties contribute significantly to the clinical presentation & impairments associated with ADHD, then those study ppts exhibiting the largest cog responses to MPH would also demonstrate the greatest clinical responses
medication and reward processing
rubia et al. (2009)
- control group & ADHD under MPH or placebo completed reward continuous performance test while in MRI scanner
- no behavioural group diffs for rewarded vs non-rewarded targets
- but activity in brain circuits associated with reward processing was normalised by the MPH
- similar results found using EEG - groom et al. (2010)
castellanos et al. (2005)
medication and RT variability
- ADHD group had worse RT variability than controls at baseline
- RT variability was reduced when ppts took MPH, but not when they took a placebo
- authors propose catecholaminergic deficiency in the ability to appropriately modulate very low-freq fluctuations in neuronal activity
coghill et al. (2014)
medication and RT variability
- meta-analysis of the effects of MPH on cog function
- medium effect size for RT variability
- majority of studies found a difference
are EFs improved by MPH
to some extent, mixed findings
is reward processing improved by MPH
brain, not beh - this is because beh gets controlled for
is RT variability improved by MPH
yes
ways that pharmacological treatments are limited: sonuga-barke et al. (2013)
further research
- normalisation is rare
- long-term effectiveness has yet to be established
- adverse effects on sleep, appetite and growth common
- some parents & clinicians have reservations about medication use
swanson et al. (2011)
further reading
- stimulant drugs
- efficacy of low oral doses of MPH and amphetamine in reducing the behavioural symptoms of the disorder as reported by parents and teachers, both for the cognitive and non-cognitive domains
- stimulant medications appear to have diff effects depending on the context of administration & the type of task required
- stimulants may shift engagement of attentional resources from favouring fast shifting stim with rewards to slow, changing stim that require maintained engagement
- little empasis has been placed on understanding the energy requirements for the cog performance & on how the stimulant medications may affect this
nonpharmacological interventions for ADHD
sonuga-barke et al. (2013)
- dietary domains - artificial food colour exclusions, elimination diet, free fatty acid supplementation
- psychological domains - cognitive training, neurofeedback, behavioural/parenting interventions
artificial food colour exclusions
- the idea that food additives influence ADHD, introduced by Feingold (1970s)
- to treat this Feingold proposed a diet free from synthetic colours & flavours
- a commonly held assumption that additives can make kids ‘hyper’
restricted elimination diest
pelsser et al. (2008)
- high number of children with ADHD have associated symptoms of allergic disorders
- suggested ADHD may be a hypersensitivity to an environmental trigger
- elimination diet minimises all or known foods that are known to be antigens/allergens
- diet involves eating ‘hypoallergenic’ foods
free fatty acid supplementation
richardson (2006), antalis et al. (2006)
- omega-3&6 fatty acids are essential for brain health & dev but most be provided by the diet
- in western cultures 3 is much lower than 6 intake
- some children with ADHD show symptoms of dry skin & excessive thirst which are associated with essential fatty acid deficiency
cognitive training
klinberg et al. (2005)
- att/WM are poor in ADHD
- can computerised training be used to improve att/WM>
- does this also have an impact on ADHD symptoms?
neurofeedback
barry et al. (2003), banaschewski & brandeis (2007)
- based on findings using EEG
- ADHD has been linked to too much slow wave activity & not enough faster activity
- has also been linked to dysfunctional slow cortical potentials which are thought to represent task-dependent engagement of cortical processing resources
- if training can be used to teach children with ADHD to regulate these brain processes then it may improve their ADHD symptoms
behavioural interventions
- difficult family envs are common in families of children with ADHD, led some to suggest that parenting practices have maintained or exacerbated disruptive beh
- parenting interventions aim to modify parental beh by
- encouraging parents to engage with their child in +ve interactive play
- teaching them behavioural management strategies
do non-pharmacological interventions work
sonuga-barke et al. (2013)
- systematic review
- in many studies raters werent blind to treatment condition
- some interventions compared to ‘treatment as usual’ e.g. medication
- effects of free fatty acid supplementation are small
- food colour exclusions may only be beneficial in those with food sensitivities
combined interventions
- multimodal treatment study of children with ADHD
- assigned to 1 of 4 groups: medication management, intensive behavioural treatment, combined, standard community care
- medication & combined groups showed a greater reduction in ADHD symptoms than the behavioural treatment & community care groups
- for other measures, the combined group improved more than the community care group while the medication only group did not