Childhood Exposure to Violence as a Risk Factor for Polydrug Use: Examining Dual Systems Imbalance and Major Depressive Disorder as Mediating Mechanisms

Polydrug use presents a priority public health issue because of the range of physical and mental health issues that may follow from the use of multiple types of drugs. Exposure to violence has been identified as a risk factor for polydrug use, but there remains limited work that has identified mechanisms linking these constructs. Major depressive disorder and differential development of dual systems (impulse control; sensation-seeking) may provide two psychological mechanisms, and mediating effects were tested here. The Adolescent Brain Cognitive Development data were analyzed. Generalized structural equation modeling was used to assess direct and indirect relationships of interest. Lifetime exposure to violence prior to Wave 2 was associated with increased drug-use variety at follow-up. Dual systems imbalance significantly mediated this relationship, whereas major depressive disorder did not. Mediation accounted for about 25% of the direct effect of exposure to violence. These findings suggest that programing to foster healthier cognitive development for youth survivors of violence may help to prevent polydrug use.