[How dangerous are patients with mental disorders?].

The question of potential violence on the part of people with a mental disease has caused considerable controversy in recent decades. While in the eighties the prevailing opinion was that they have no increased risk of aggression, recent studies, especially from Scandinavia and Canada, show a moderate but reliable coherence between violent crime and paranoid and schizophrenic diseases. The danger of people with a mental disease is assessed essentially through the following five study-approaches: Studies to assess the criminal rate of hospitalised patients, the prevalence of mental disorder, studies on prisoners who are committed to a psychiatric facility, and long-term analyses of cohorts. Special emphasis is attached to investigations on homicides. Other investigative questions are concerned with the influence of psychopathological symptoms, the importance of comorbid disturbances and sociological aspects. The studies agree that the risk of violence is decisively increased in people who suffer from schizophrenia, through additional substance abuse, comorbidity with personality disorders, absence of treatment and social desintegration. An unprejudiced approach to this sensitive theme of aggression in people with schizophrenia with regard to further effective prevention and therapy is required.