Epidemiology |
| The incidence of AD/HD in the parents of children newly diagnosed with AD/HD is 25% indicating a strong genetic predisposition.(23)
Analysis of twin data can be used to partition the variance of a characteristic into a genetic component and an environmental component. Concordance for measures of inattentiveness are higher for monozygotic twins than same sex dizygotic twins. Statistical analysis estimates that genetic effects accounted for approximately half of the explainable variance in hyperactivity and inattentiveness among twin pairs. The link between adverse family and perinatal factors with hyperactivity is weak.(24) The strong genetic component of this disorder supports the hypothesis that the etiology of AD/HD is neurobiological. |