Influence of the type of childhood violence on cannabis abuse and dependence among adolescents: a systematic review and meta-analysis/Tipos de violencia en la infancia que inciden en el abuso y dependencia de cannabis entre adolescentes: una revision sistematica y metaanalisis

The use of cannabis for recreational purposes has increased worldwide, and the proportion of cannabis users in the adolescent population is high. Susceptibility to cannabis use involves various factors, including childhood adversity; however, the effects of different types of violence on cannabis use have not been evaluated. The aim of this review was to analyze the effects of different types of violence on cannabis use in adolescence. We searched electronic databases (PubMed, Science Direct, Web of Science, Ovid and CONRICyT) using the following algorithm: (("Cannabis" OR "Marijuana Smoking" OR "Marijuana Abuse") AND ("Child Abuse" OR "Domestic Violence" AND "Adolescent")), considering all articles published up to November 3th, 2017. Odds ratios (ORs) were calculated for the effects of experiencing different types of violence during childhood on cannabis use. Six studies, representing 10 843 adolescents of both sexes, were ultimately included in the systematic review and meta-analysis. Three types of early-life adversity were associated with cannabis abuse/dependence: physical abuse (OR: 1.58, 95% CI [1.01-2.46]), sexual abuse (OR: 2.35, 95% CI [1.64-3.35]), and witnessing violence (OR: 3.22, 95% CI [0.63-16.54]). The results indicated that two specific types of child maltreatment, sexual and physical abuse, were critical factors affecting vulnerability to cannabis use in adolescence. The number of studies examining other types of violence was limited. The results highlighted the importance of enhancing efforts to prevent violence, particularly sexual abuse, as part of integral programs designed to prevent cannabis abuse and dependence.