Personality traits and disorder in depression.

The authors examined the relationship of personality traits and personality disorder to depressive subtype, descriptive characteristics, and outcome in 160 depressed inpatients. Personality disorder was significantly more common in unipolar nonmelancholic depressed patients (61%) than in unipolar melancholic (14%) or bipolar depressed patients (23%). Personality disorder did not affect symptom manifestation but was related to earlier onset of depressive illness and worse outcome within the unipolar nonmelancholic group. Obsessive traits were most common in the unipolar melancholic patients, while histrionic, hostile, and borderline traits predominated in the nonmelancholic patients. The authors discuss the usefulness of a multiaxial diagnostic system and the importance of separating trait and disorder in personality assessment.