Psychopathology has been assessed in opiate addicts using both symptom rating scales and diagnostic impressions. The authors present a study of diagnoses among 533 addicts seeking treatment and show high rates of depression, alcoholism, and antisocial personality disorder. Depressive disorders are associated with poor social functioning in a wide variety of areas. The longitudinal course of depression in addicts is to generally resolve within 6 months without specific treatments, with only 2 per cent of addicts being currently depressed at both intake and 6-month follow-up. The high prevalence (74 per cent lifetime rate of affective disorders in addicts) and transient nature of affective disorders among addicts suggests that short-term crisis treatments to deal with their large number of recent life events would be helpful.