BACKGROUND: Depression is highly prevalent among individuals with substance use disorders (SUDs), especially women, and has been noted to improve during SUD treatment. Perceived stress is independently related to severity of depression and substance use disorders (SUDs) as well as recurrence of symptoms and relapse following treatment. The aim of this study was to investigate among adults enrolled in SUD treatment whether levels of perceived stress and substance use over the course of treatment were related to reduction in depression.

METHODS: This is a secondary analysis of data from the Women's Recovery Group Study. Women (n = 100) were randomized to either single- or mixed-gender group therapy and men (n = 58) received mixed-gender group therapy. Measures of substance use, perceived stress and depressive symptoms were collected for 6 months following treatment completion. In this study, we used lagged mixed models to investigate whether levels of substance use and perceived stress at each time point were associated with changes in depression at the subsequent time point.

RESULTS: Results indicated that depressive symptoms significantly improved over time. Both substance use and perceived stress were associated with subsequent depressive symptoms. Importantly, stress was associated with symptoms when controlling for substance use, suggesting that changes in depressive symptoms were not solely attributable to levels of substance use.

CONCLUSIONS: These results suggest that both stress and substance use are associated with improvements in depressive symptoms in substance use disorder treatment. Although preliminary, these results provide further support for the importance of targeting stress reduction in people with substance use disorders.