Psychiatric disorders in the relatives of depressed probands. I. Comparison of prepubertal, adolescent and early adult onset cases.

Research with adults suggests that early onset of depression is associated with increased rates of depression among relatives. This paper presents results, of a family study that tested the hypothesis that prepubertal depression was associated with a greater familial loading of depression than the postpubertal form, which in turn had a greater familial loading than adult onset depression. Probands were from a child to adult longitudinal study. Psychiatric disorders among relatives were assessed with family interview and family history methods 'blind' to all findings regarding the proband. Contrary to expectation, familial rates of depression did not differ significantly between the groups. However, manic disorders tended to be more common among the relatives of postpubertal depressed cases than among the relatives of adult onset cases. Moreover, relatives of prepubertal depressed subjects had higher rates of criminality and family discord than postpubertal subjects. Prepubertal onset depressive disorders appear to be relatively distinct from postpubertal forms.