A CASE-CONTROL FAMILY HISTORY STUDY OF DEPRESSION IN ADOLESCENTS

Objective: To examine whether depression aggregates in the families of depressed adolescents and to determine whether clinical features and/ or comorbid syndromes in the depressed adolescents change the risk of psychopathology in relatives. Method: Lifetime prevalence rates of psy chopathology in the first-degree (n = 228) and second-degree (n = 736) relatives of 76 adolescents with major depressive disorder (MDD) and the first-degree (n = 107) and second-degree (n = 323) relatives of 34 normal control adolescents were assessed by the Family History-Resear ch Diagnostic Criteria (FH-RDC) method using the parent/guardian as th e family informant. Results: Compared with the first-degree relatives of normal controls, the relatives of depressed adolescents had signifi cantly higher lifetime rates of MDD (25% versus 13%) and ''any'' of th e FH-RDC psychiatric disorders (53% versus 36%). The second-degree rel atives of adolescents with MDD had significantly higher lifetime rates of FH-RDC ''other'' psychiatric disorder (12% versus 7%) and ''any'' of the FH-RDC psychiatric disorders (22% versus 15%) but not MDD (5% v ersus 6%) compared with the relatives of normal controls. The first-de gree relatives of depressed adolescents who were also suicidal had inc reased lifetime rates of suicidal behavior which significantly cosegre gated with MDD. Comorbid conduct disorder in the depressed adolescent was associated with increased rates of antisocial personality disorder in the first-degree relatives and also tended to cosegregate with MDD . Conclusions: The current study provides further evidence for the fam ilial aggregation of depression in adolescent-onset MDD. This study al so suggests that the familial aggregation of nonaffective psychiatric disorders depends on the clinical features and comorbid syndromes pres ent in the depressed adolescent proband.