Schizophrenia-Associated Violence and Comorbid Substance Abuse

Many studies have found that schizophrenia increases the risk for violence, but questions remain about the degree of risk and the influence of co-occurring substance use disorders. In a study that included more people with schizophrenia than all previous longitudinal studies combined, researchers carefully analyzed the roles of concurrent substance abuse and familial factors. Using Swedish registry data, researchers examined convictions for violent crime in 8003 persons with at least two discharge diagnoses of schizophrenia and in 80,025 age- and sex-matched controls. Analyses were also done on a subgroup of 4674 patients and their 7780 unaffected siblings.

Substance use disorders were determined through discharge diagnoses. The risk for vio…