The impact of depression on the outcome of addictions treatment.

The objectives of this study were to examine the prevalence and presentation of depression among patients with substance use disorders, and to explore the relationship between depression and the outcome of addictions treatment. Seventy-five patients were consecutively recruited upon entering addictions treatment, and were assessed by clinical and semi-structured interviews, Hamilton Rating Scale for Depression, Global Assessment Scale, and Beck Depression Inventory. At intake, 22.4% of patients had primary depressive disorders, 8.4% had substance-induced depressions, and 5.6% had mixed features of primary and substance-induced depressions. Female and alcoholic patients were more likely to suffer from both primary and substance-induced depressions. At 3 months, 93.3% of patients were reinterviewed. Depressed patients had longer duration of abstinence and greater decreases in symptomatology. Patients with substance-induced depression achieved almost complete discontinuation of primary substance use. Depression had a significant impact on addictions treatment outcome, but many important predictors of outcome have not yet been identified.