[The role of genetic load in the development of reactive psychotic states leading to severe violence. Study of a case of "homicide arson" double and extended suicide].

Using the casuistic presentation of a case of arson with ensuing double murder and extended suicide by jumping over a rock face, we discuss to what extent genetic disposition is important for the formation of reactive-psychotic states that lead to crimes of extreme violence. From the results of protracted research on the previous history of the perpetrator and of his relatives, a multifactorial disposition toward affective psychoses, alcoholism, epilepsy, and suicide was discovered. On the other hand, in the long-term longitudinal observation of the perpetrator, manic depressiveness was diagnosed, which was characterized by a rapid bi-polar phase shift. This supports the opinion of the authors--partially contradictory to the literature--that such affective outbursts, which have apparently arisen purely reactively, but which lead to murder and suicide, in most cases arise on an endogenic basis. In such cases one should not speak of an exclusively reactive depression (mania) before the possibility of an endogenic component has been excluded. The latter, however, can only be detected through precise long-term longitudinal diagnosis and data on the family's psychiatric history. Otherwise, an endo-reactive depression (mania) must be diagnosed. This implies in these cases at least an "irresistible impulse" (Dispositionsunfähigkeit) of the perpetrator.