Impact of substance use disorders on self- and other-directed violence : an integrated model approach

Abstract

Background: In 1996, the World Health Organization (WHO) published its resolution WHA49.25, declaring violence to be a “leading worldwide public health concern”. Judging by current available data, it remains so. Questions persist regarding the typology of violence, its determinants and predictors, and its management and treatment. Several explanatory models have addressed these questions separately for self-directed (i.e. suicide) and other-directed (i.e. interpersonal-assaultive) violent behavior and have found similarities in risk and predisposing factors. Substance (alcohol and illicit drugs) use has been identified as an independent environmental risk factor for perpetration of both types of violence through different mechanisms, including the mediating effect of impulsivity. Given that extensive epidemiological, clinical and neurobiological research has shown that self- and other-directed violence share similarities in predispositions and stressors, one important question stands out: what are the determinants of directionality, i.e. choosing the target of the violent behavior? To answer this question, an integrated conceptualization of violence is required. Hypotheses: Our hypotheses are: (1) alcohol use disorder’s association with overall violence will be stronger than that of drug use disorders; (2) drug use disorders will act as a “force of direction” towards interpersonal violence as it will significantly increase the odds of assault compared to suicide attempts; (3) cannabis use disorder will act as a “force of direction” towards interpersonal violence as it will significantly increase the odds of assault compared to suicide attempts; (4) age will modify the association between alcohol and drug use disorders, and suicide attempts, assaults and overall violence, with the association being strongest among youth. Objectives: Our objectives are: (1) to measure the association between alcohol and-or drug use disorders and different types of violence (attempted sui