Psychiatric disorders and among them depression are common in substance dependant patients. The aim of this study is to compare the clinical characteristics of those that appear to have substance induced depression and those that have independent majordepression.

184 independent and 187 opium induced (OID) depressed male patients that met the DSM-IV criteria for major depressive disorder were randomly selected. Standard demographic data, including age, marital, employment and education status were collected. The primary measure of depressive signs and symptoms was Hamilton Depression Scale (HAMD-21).The two groups were compared with each other for the HAMD total and subscales scores.

The two groups were matched regarding age, educational level and marital status. Opium induced depressed patients were more severely depressed and motor retarded and also they had more social and occupational problems. Gastrointestinal, sexual and somatic complaints were more common among them too. MDD patients had better insight than the other group.

The results demonstrate that it ispossible to differentiate between substance-induced andindependent depression. Such differentiation mightbe important for establishing prognosis and optimal treatment.