Comorbidity constituted a heavy burden on the medical services. Depression might affect pattern of SUD in several manners. METHOD: SUD males inpatients in Abbaseya Mental Hospital, psychiatric and SUD sheets, addiction severity index, and Hamilton rating scale were applied. CONCLUSION: depressed SUD patient differed from patients of SUD only: higher rate and duration of hospitalization, higher rate of abstinence, higher rate of suicidal behavior, and higher score in ASI in medical, social and psychiatric items.