Psychotic motivation and the paradox of current research on serious mental illness and rates of violence.

Persuasive empirical support exists for a positive association between serious mental illness (SMI) and rates of violence; a great deal of support is also present for the clinical impression that psychotic symptoms sometimes motivate "symptom-consistent" violence. We propose that the issue of the motivation for violence in the SMI population can be considered independently of the issue of the association between SMI and violence rates. We review much of the current literature on the association between SMI and violence in a framework that emphasizes motivational influences unique to the SMI population. We conclude that the contribution of psychotic motivation to rates of violence in the SMI population is a major research issue. Furthermore, we believe that recognition of the independence of motivational influences and violence rates, and consideration of the impact of treatment on violence, may help explain the paradox of current research: Delusions and hallucinations may motivate violent behavior, but this psychotic motivation may not be reflected in the actual rate of violence.