[Etiological concepts of chronification in schizophrenia]

Kraepelin and Eugen Bleuler understood the chronicity of schizophrenia as a typical expression of its natural course. Although they erred in this pessimistic assessment, some 30-35 % of all schizophrenia patients do suffer from chronic residual symptoms after years of having the disease, despite sociopsychiatric reform efforts that led to open hospitals and greater patient autonomy. According to the vulnerability conception, schizophrenia is regarded as a vulnerability that causes decompensation leading to psychotic episodes under the influence of internal and/or external stressors. The vulnerability threshold can be increased or lowered by influencing variables. In addition to factors immanent to the disease, some of these variables are related directly or indirectly to chronicity of the disease.