Plasma Dopamine-β-Hydroxylase and Platelet Monoamine Oxidase in Attention Deficit Disorder and Conduct Disorder

The authors examined platelet monoamine oxidase (MAO) and plasma and dopamine-β-hydroxylase (DβH) activity in 48 hoys with Attention Deficit Disorder (ADD) and 24 healthy control subjects. Eight of the hoys with ADD met criteria we established for Conduct Disorder, undersocialized type (UCD). Both MAO and DβH were lower in ADD with UCD than in ADD without UCD. Also. DβH was lower in ADD with UCD than in control subjects. For the full group of ADD subjects, neither MAO nor DβH differed from control values. The results suggest that UCD may he associated with lower values of the enzymes DβH and MAO. In future biological studies of ADD, it appears important to control for, and separately analyze, those patients with a concurrent diagnosis of Conduct Disorder J. Am. Acad. Child Adolesc. Psychiatry, 1988. 27. 2:171–174.