Childhood abuse as a risk factor for injection drug use: A systematic review of observational studies

Issues Childhood abuse is a public health challenge with lifelong impacts, including future drug use. However, previous research has been mixed regarding impacts on injection drug use. This systematic review examines the impact of childhood abuse (sexual, physical and emotional) on adult injection drug use. Approach We searched MEDLINE, EMBASE, PsycINFO, CINAHL, Web of Science and grey literature to identify relevant studies from database inception to 26 September 2018. Studies were eligible if: (i) they were empirical original research published in English; (ii) considered childhood abuse as potential risk factors for lifetime history of injection drug use; and (iii) included adult participants. Risk of bias was assessed using the modified Newcastle-Ottawa Scale. Key Findings Of the 1994 articles screened, 17 studies met the inclusion criteria. Most studies were conducted in the USA and utilised cross-sectional research designs. All of the 17 studies measured sexual abuse, six studies measured physical abuse and three studies measured emotional abuse; most (N = 11) of which reported a statistically significant and positive association between at least one sub-scale of childhood abuse and injection drug use. Implications Our findings highlight the need for devising interventions to reduce the harms associated with childhood abuse. Conclusions The evidence base suggests a significant positive association between experiences of childhood physical abuse and elevated risks of injection drug initiation with mixed results for sexual and emotional abuse.