[50 years after Manfred Bleuler. What do we know today about late-onset schizophrenia(s)?]

Since Manfred Bleuler's description of the clinical picture of late onset schizophrenia over 50 years ago, debate has persisted as to whether it is justifiable to differentiate this as a valid, independent entity from the group of classic schizophrenic disorders with early onset. As this review shows, this question cannot be answered unequivocally even now. It must rather be remarked that we have neither been able to decisively extend our knowledge since Manfred Bleuler's comprehensive contribution, nor managed to achieve a much sounder basis methodologically. The reasons for this are the international conceptual and terminological confusion that has developed around this illness group, and on the other hand the methodological limitations of the empirical studies conducted on this clinical picture so far.