[Classification of endogenous psychoses. Predictive validity of initial diagnosis based on 5 and 21-33-years of...

As regards the clinical psychopathological diagnostics, Leonhard's classification of endogenous psychoses published in 1957 contained description of a detailed nosology with claims that the diagnostic categories included in this classification system involve differentiated predictions of course and outcome of the illness. The principal investigator (BP) chose Leonhard's classification system to test these nosological hypotheses via a prospective study of psychotic patients based on their clinical and life history in 1966-67. Validity of the categorial diagnoses given at baseline (female patients n=222; healthy control persons n=54; 1968-1976) was proven by combination of assessments of psychopathological symptoms and personality types at the 5-year follow-up. Moreover, "pure defect" also proved to be valid (84,6%). At the time of the long-term follow-up in 1997-2002 (patients: n=125; healthy control persons: n=38) predictive validity of the nine categories was measured empirically and by using a stochastic (Markovian) model, thus combining validity and reliability. Hebephrenias, group of normal persons and of schizophrenias proved to be valid, with diagnostic stabilities of 0,93, 0,89, and 0,93, for the three groups, respectively. In addition, bipolar manic-depressive psychoses and cycloid psychoses were also valid (diagnostic stability of 0,76 in both cases). Unipolar depression was valid (diagnostic stability=0,84) only by forming a "nosological family" based on diagnostic stability and on current status and clinical presentation during the period preceeding the follow-up with regard to other moodcongruent disorders and outcome-diagnosis "healthy control". Validity of systematic paraphrenias (diagnostic stability =0,68) was also in the moderate range. Division of schizophrenias in "systematic vs. non-systematic" nosological categories was inconclusive; the categories of affect-laden paraphrenia, periodic catatonia and systematic catatonias could not be confirmed reliably in this study.