Psychiatric disorders in the relatives of probands with prepubertal-onset or adolescent-onset major depression.

OBJECTIVE: To determine whether the familial risk of major depressive disorder (MDD) varies with either onset, recurrence, or continuity of MDD in adulthood in prepubertal- compared with adolescent-onset probands.

METHOD: Seventy-six prepubertal-onset MDD, 59 adolescent-onset MDD, and 78 never psychiatrically ill probands were assessed as children or adolescents and were evaluated 10 to 15 years later as adults, by an independent team that was blind to the initial diagnoses. At follow-up, psychiatric disorders among 731 of their first-degree relatives were assessed using direct interviews and family history methods by investigators who were blind to the clinical status of the probands.

RESULTS: Both prepubertal- and adolescent-onset MDD were significantly associated with a family history of MDD. The familial rates of MDD and other psychopathology did not vary between the 2 groups. For prepubertal-onset MDD, family history was significantly associated with recurrence and nonsignificantly associated (trend) with continuity into adulthood. In contrast, there was no association between a family history of MDD and either recurrence or continuity into adulthood of adolescent-onset MDD.

CONCLUSIONS: Prepubertal- and adolescent-onset MDD are both associated with a family history of MDD, but only in prepubertal-onset MDD is familial loading associated with recurrence and continuity of MDD into adulthood.