High rate of affective disorders in probands with attention deficit disorder and in their relatives: a controlled family study.

In a controlled family study of attention deficit disorder, data were collected on first-degree relatives of 22 children with attention deficit disorder and 20 normal children. The rate of major affective disorder was significantly higher in the attention deficit disorder probands (32%) and their relatives (27%) than in the normal control subjects (0%) and their relatives (6%). The findings indicate that attention deficit disorder is associated with higher risk for affective disorder and suggest that probands who have both disorders may represent a distinct subgroup.