Janusz Rybakowski: 120 years of the Kraepelinian dichotomy of "endogenous psychoses" in historical perspective


Nassir Ghaemi’s comment on Hector Warnes’ Comment


        The Keshavan, Nasrallah and Tandon (2011) study should not be interpreted in isolation. There is a large literature on schizophrenia versus affective illness and the role of the schizoaffective concept. A 45% overlap is not consistent with many other studies. It depends on how you define the condition and what kind of study. Overlap in symptom studies is common, but it is the least meaningful nosologically. If you did a symptom study of primary asthma versus cigarette-related chronic obstructive pulmonary disease (COPD), you would find a lot of symptom overlap.

        I really don’t understand why we psychiatrists keep talking about symptoms so much. This was indeed one of Kraepelin’s key insights, lost again in our false DSM ideology: symptoms overlap in medicine and psychiatry. That’s nothing new or interesting. You have to use some other criterion to establish diagnostic validity – not symptoms, but something else: pathology, course of illness, laboratory tests, genetic markers. 

        In fact, if you use genetics, looking at classic genetic studies of the schizoaffective question, like the Roscommon family study, the diagnostic overlap between schizophrenia and affective illness is nowhere near 45%. It’s quite small, and completely consistent with the statistical likelihood of random comorbidity of those two conditions in the same family lineage. 

        So I see no need to invoke the ever-present favorite ghost of the pre-Kraepelinian and anti-Kraepelin unitary psychosis model.  That would be like saying that since I can’t see  beyond the horizon, I will return to the theory that the earth is flat.  There are other explanations.

        On the comment on Dr. Moller’s paper, I have not read the latter so cannot comment at length. Of the points made by Dr. Warnes, I would suggest that the concept of spectrum conditions does not conflict with Kraepelin’s nosology, but rather is consistent with it:  MDI was one large spectrum from full mood recurrent mood episodes to mild chronic affective temperaments.  Dementia praecox was a spectrum from severe chronic psychosis to mild “schizothymia” as Kretschmer later put it.  As I described above, these spectrum concepts are part and parcel of Darwinian biology and were well-known to Kraepelin and accepted by him.

        It is the psychiatric profession, not Kraepelin, who has created false absolute categories, before and after DSM-III, and then confusedly wondered what is what? 

        As in the old saying: Men first raise a dust, and then complain they cannot see.



Keshavan MS, Nasrallah HA, Tandon R. Schizophrenia, "Just the Facts" 6. Moving ahead with the schizophrenia concept: from the elephant to the mouse. Schizophr Res. 2011; 127(1-3):3-13.


July 23, 2020