Childhood sexual abuse and risk for initiating injection drug use: a prospective cohort study.

OBJECTIVE This study examined whether childhood sexual abuse predicts initiation of injection drug use in a prospective cohort of youth. METHOD From October 2005 to November 2010, data were collected from the At Risk Youth Study (ARYS), a prospective cohort study of street-involved youth in Vancouver, Canada. Inclusion criteria were age 14-26 years, no lifetime drug injection, and non-injection drug use in the month preceding enrollment. Participants were interviewed at baseline and semiannually thereafter. Cox regression was employed to identify risk factors for initiating injection. RESULTS Among 395 injection-naïve youth, 81 (20.5%) reported childhood sexual abuse. During a median follow-up of 15.9 months (total follow-up 606.6 person-years), 45 (11.4%) youth initiated injection drug use, resulting in an incidence density of 7.4 per 100 person-years. In univariate analyses, childhood sexual abuse was associated with increased risk of initiating injection (unadjusted hazard ratio [HR], 2.38; 95% confidence interval [CI], 1.29-4.38; p=0.006), an effect that persisted in multivariate analysis despite adjustment for gender, age, aboriginal ancestry and recent non-injection drug use (adjusted HR, 2.71; 95% CI, 1.42-5.20; p=0.003). CONCLUSION Childhood sexual abuse places drug users at risk for initiating injection. Addiction treatment programs should incorporate services for survivors of childhood maltreatment.