What are 3 important other factors to diagnose with ADHD
- Before age 12
- 2+ settings
- Must interfere and reduce functioning
What are the two dimensions of symptoms for ADHD?
- Inattention
2. Hyperactivity/impulsivity
What are some environmental factors that cause ADHD?
Abuse, neglect, family adversity, situational stress
What are some genetic origins of ADHD and how heritable is it?
- 0.75 (so chance that ADHD is driven by genetics is 75%)
- Polygenic disorder
- DR4 (less efficient receptor, can’t hold on to dopamine)
- DAT (dopamine transporter)
- If mom smokes while pregnant and baby has bad DR4 and DAT risk variants, then child has 9x more risk of getting ADHD
Key brain regions in ADHD
Show a 3-10% reduction in volume of…
- Orbital PFC
- Working memory and exec fxn - Basal ganglia
- Cerebellum (esp vermis)
Also involved…
- R. inf PFC
- behavioral inhibition - Anterior cingulate
- Decrease use in problem solving. Instead use fronto-striato-insular-thalamic network which is slower
- Stimulates fix this - Nucleus accumbens
- Has less DAT
Why can some people outgrow ADHD?
There is a 3 year lag in brain development in kids with ADHD. Some kids catch up! Lag is esp large in frontal cortices
What are the postulated neuro chemical deficits in ADHD?
Dopamine and norepinephrine
-comes from the fact that stimulants inc dopamine and NE transmission
What is something important to know about catecholamines and the PFC?
The PFC requires a moderate amt of catecholamines. Too much=stress and too few=fatigue
