[The role of endogenous and exogenous factors in the development of paroxysmal schizophrenia].

Clinical and epidemiological examinations of 347 patients with attack-like schizophrenia and their relatives of the first degree kinship (2688 persons) have demonstrated that the lack of hereditary load and pathological character traits in the premorbid period, and the middle age at which the disease becomes manifest are favourable factors of the development of this pathology debut. The following factors are unfavourable: hereditary load with regard to schizophrenia, the schizoid type of the premorbid condition, the presence of "exogenous" provocation" and early disease onset.