Studies conducted over the past 3 decades have consistently reported an association between mental illness and violence. The authors propose a sociologically inspired explanation for this association by referring to the Thomas Theorem—if situations are defined as real, they are real in their consequences. Identified were a small subset of psychotic symptoms, termed "threat/control-override" symptoms, that tend to induce violence because they influence the definitions of situations. The data come from an epidemiological study conducted in Israel that included a psychiatrist-administered diagnostic interview with 2,678 Ss aged 24–33 yrs. Results show an association between behaviors and psychiatric diagnosis that cannot be accounted for by sociodemographic variables. Threat/control-override symptoms are also strongly related to violent behaviors and explain a substantial part of the association between violence and psychiatric diagnoses. Other equally severe psychotic symptoms are not related to indicators of violence when threat/control-override symptoms are controlled. These findings support the authors' explanation for the association between mental illness and violence, and challenge the stereotype that most people with mental illnesses are dangerous.

Citation
Francis T. Cullen et al., Real in Their Consequences: A Sociological Approach to Understanding the Association Between Psychotic Symptoms and Violence, 64 American Sociological Review 316–332 (1999).