Clinical overlap among familial subtypes of unipolar depression.

Unipolar depressives (n = 288) were subclassified according to family history. Depression spectrum patients (DSD; n = 104) were defined as those with first-degree relatives suffering from alcoholism. Familial pure depression patients (FPDD; n = 86) were those with only depression in the immediate family, and sporadic depressive patients (SDD; n= 98) had negative family histories. An analysis was performed using index symptoms, precipitating events, and premorbid personality features. A positive family history was associated with greater premorbid personality difficulties. This pattern was highlighted when each was compared to SDD. DSD and FPDD could not be differentiated from each other. The differences between them and SDD could not be explained by the differing age distribution. Overall, the premorbid and index symptom differences were not striking enough to be clinically useful.