Validity and reliability of Leonhard's classification of endogenous psychoses: preliminary report on a prospective 25- to 30-year follow-up study

A 25- to 30-year controlled follow-up investigation of endogenous psychoses started in 1997. The research program labeled "Budapest 2000" was initiated in 1967 as a controlled prospective study. The assessment of 108 patients and 24 normal control persons has so far been completed. With regard to the "middle groups" in the Leonhardian classification, diagnoses of bipolar manic-depressive psychosis, cycloid psychosis, periodic catatonia, systematic paraphrenia, systematic catatonia and hebephrenia proved to be valid in the long term. Revision of the category affect-laden paraphrenia seems to be called for.