When is the peak onset of ADHD?
3/4 yo
How many children does ADHD affect?
3%-5% children, prevalence higher in areas of socio-economic disadvantage
What is the Male/Female ratio for ADHD?
- 4:1 for the hyperactivity /impulsivity type
- 2:1 for the inattention type
What is the Comorbidity rate for ADHD?
50% of the children also show another psychiatric disorder
Does ADHD persist into adolescents?
Persists in adolescence for around 50-80% of individuals and in adulthood for around 30-50% of individuals
How much more at risk for ADHD are siblings?
3-5 more
What is the concordance for ADHD in twins?
Concordance is higher in monozygotic twins (50%-80%) than dizygotic twins (33%)
What are the 7 Candidate genes?
- 5 are linked to dopaminergic system (esp. DAT-1 and DRD4)
- 2 are linked to the serotonergic system
Doe alcohol and nicotine use imcrease ADHD chances?
YES - But mothers themselves more likely to have ADHD and ADHD increases the use of substance!
What are some risk factors for ADHD?
- Low birth weight and premature birth
- Obstetric complications
- Maternal stress
- Exposure to lead during childhood
- Complex pathway from genes to symptoms
What is an Endophenoytpe?
heritable, vulnerability traits that mark a risk for the development of the disorder
