Lecture 5: ADHD Flashcards
Name the main symptoms of ADHD according to DSM-5. What are additional features that need to be present for a diagnosis?
Age-inappropriate levels of: (1) inattention and / or (2) hyperactivity / impulsivity.
Age of onset needs to be <12, the symptoms need to have a significant effect on daily functioning, they need to occur in multiple settings and must not be caused by a different disorder.
What is the prevalence of ADHD. How does it develop over time and geographical location?
ADHD is diagnosed in 5-7% of children and adolescents. Approximately 5% of adults are diagnosed, too. The symptoms appear to be quite stable over time and location. ADHD is much more prevalent in boys than in girls.
Name some common comorbidities of ADHD.
Autism Spectrum Disorder (65-80%), conduct disorder (40%) and addiction (2x risk).
What is the percentage of heritability of ADHD?
Approximately 75%.
What might be the causes of ADHD?
An interaction between genes and environment, affecting brain development, which in turn impairs cognitive functioning.
Name the three main cognitive areas that show impairment in ADHD.
Cognitive control, timing and reward processing.
How is ADHD related to brain volume? Which cortical and subcortical areas are particularly involved in ADHD?
In ADHD there is smaller brain volume, with an average reduction of 3-5%. Cortical areas involved are the dorsolateral prefrontal cortex, the ventromedial prefrontal cortex and the parietal cortex. Subcortical regions involved are the frontostriatal circuit, including the anterior cingulate cortex and the basal ganglia, and the cerebellum.
How are the affected brain areas in ADHD related to the cognitive dysfunction in patients?
The dorsal frontostriatal regions are related to cognitive control deficits, the orbitofrontostriatal circuits are related to reward processing and the frontocerebellar circuits are related to timing.
How is cortical thickness related to ADHD? Which brain area is mainly affected and how does the thickness develop over time?
There is thinner (predominantly frontal) cortex in ADHD. The cortical thickness increases over time but is delayed by approximately 3 years. The left medial PFC remains thinner.
What are the results of Diffusion Tensor Imaging in ADHD?
Patients show lower white matter integrity.
What are the main results of fMRI analysis in ADHD?
fMRI indicates dysfunctioning across the whole brain, with hypoactivation in the frontoparietal network, the ventral attention network and the frontostriatal network. Hyperactivation was found in the somatomotor network, the dorsal attention network and the default mode network.
Regarding EEG, what are the main findings in ADHD?
ADHD patients show increased theta waves (related to relaxed and sleepy states) and decreased beta waves (related to attention and focus).
Name respectively two evidence-based and two alternative methods for treating ADHD.
Evidence-based treatments include behavioral therapy and pharmacological treatment. Alternative treatments include cognitive training and neurofeedback.
For ADHD, pharmacological treatment mainly includes two groups of medication. Which neurotransmitter systems are influenced by these medications? How effective are pharmacological treatments?
The first group includes stimulants that are affecting the dopaminergic and noradrenergic systems. An example is methylphenidate (Ritalin). The second group includes non-stimulants that affect only the noradrenergic system. These medications are highly effective in about 70% of the patients.
What are the short-term and long-term effects of pharmacological treatments in ADHD?
Short-term: cognitive enhancement (memory, reaction time variability, inhibition), normalization of activity and connectivity in the right inferior frontal cortex and insula (cognitive control).
Long-term: normalization of caudate nucleus activation (attention) and normalization of structure, including white matter, anterior cingulate cortex, thalamus and cerebellum.
