[What makes a mental ill violent?].

From numerous tests it is clearly to be concluded that between severe mental health problems and the act of violence exists a moderate, but reliable association. With this conclusion, neither old fears of "an unpredictable insane person" should be reactivated nor stigmatisation are to be carried out. Particularly since the whole of humans with psychological disturbances does not exhibit an increased act of violence risk in relation to the average population. It is however necessary to identify subgroups with increased tendency for self- and other aggressive behaviour, to describe aggression-aroused and reducing factors and to appreciate the positive influence of the psychiatric therapy and the social rehabilitation. After today's level of knowledge it is to be proceeded from the following risk indicators: Diagnosis of a paranoid disturbance, male sex, correlation with personality disorder and substance abuse, lack of treatment, increasing social disintegration with a longer treatment process and uncertain competence for the support. Extensive psychiatric treatments reduce the risk clearly. The deinstitutionalisation does not have negative influence with secured ambulatory support. The legal accommodation framework, which is discussed on the basis of the Austrian law situation, is an important modifying factor. Relating to the mental health problem there is just a little relation to the aggressive behaviour in comparison to the average population.