The classification of functional psychoses:: The impact of ICD-10 diagnoses (research diagnostic criteria) for the prediction of the long-term course

One major objective of Emil Kraepelin's system of the functional psychoses was to establish a prognostically relevant diagnostic classification. Following this idea, 197 first admitted inpatients from the years 1980 - 1982 were examined 15 years later in order to determine the impact of ICD-10 diagnoses (derived from first hospitalisation) for the long-term course. The long-term course was divided into the three course types single episode, episodic-remitting course and chronic course. The results showed that 57% of the patients with schizophrenia, 50% of the patients with persistent delusional disorders, 20% of the patients with acute and transient psychotic disorders, 10% of the patients with schizoaffective disorders and only 3% of those with affective disorders developed a chronic course type. Using a logistic regression analysis, the predictive validity of the ICD-10 diagnoses was compared with those of a dimensional model based on psychopathological and demographic data. The results revealed that the predictive validity of the dimensional model (77%) does not exceed the predictive validity of ICD-10 diagnoses (78%).