The role of depression and social support in non-fatal drug overdose among a cohort of injection drug users in a Canadian setting.

OBJECTIVES Non-fatal overdose remains a significant source of morbidity among people who inject drugs (IDU). Although depression and social support are important in shaping the health of IDU, little is known about the relationship between these factors and overdose. Therefore, we sought to determine whether depressive symptoms and social support predicted non-fatal overdose among IDU in a Canadian setting. METHODS Data were derived from three prospective cohorts of people who use drugs: the Vancouver Injection Drug Users Study (VIDUS), the ACCESS Cohort, and the At-Risk Youth Study (ARYS). Multilevel modeling was used to determine if depression and social support were significant predictors of non-fatal overdose across time. Analyses were stratified by sex. RESULTS There were 1931 participants included in this analysis, including 653 (33.8%) females and 69 (3.6%) youth 20 years old or younger. Depressed men (adjusted odds ratio [AOR]=1.53, 95% confidence intervals [CI]=1.25, 1.87) and women (adjusted odds ratio [AOR]=2.23, 95% confidence intervals [CI]=1.65, 3.00) were more likely to experience a non-fatal overdose. Further, among women, those who reported having 3 or more persons they could rely upon for social support were less likely to experience a non-fatal overdose (AOR=0.54, 95% CI 0.31, 0.93). CONCLUSION Although depression was a significant predictor of non-fatal drug overdose, social support was a significant predictor among women only. Possible strategies to prevent non-fatal overdose may include identifying IDU experiencing severe depressive symptoms and providing targeted mental health treatments and mobilizing interpersonal social support among IDU, especially among women.