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

Hector Warnes’ comment on Hans-Juergen Möller’s “Kraepelin’s dichotomy and beyond”


        When Tom Ban invited Hans-Juergen Möller to comment on Janusz Rybakowski’s essay Professor Möller offered instead to send him his paper titled “Systematic of psychiatric disorders between categorical and dimensional approaches Kraepelin’s dichotomy and beyond,” published in 2008. The following is my comment on Möller’s article.

        This is a very dense and highly academic study of psychiatric taxonomy or nosology by Prof. Möller who has written extensively since the decade of the ‘70s on methodological and clinical issues in psychiatry including follow up studies of the major psychoses. It reminded me of the exceptional paper published by E. Stengel in 1959 which raises similar problems but in addition has an amazing historical perspective, not leaving practically any country out of the core issues that confront us. The categorical or dimensional approach and the reliability and/or validity of diagnostic entities, for which there is conflicting evidence, is underlined by Professor Möller who discusses a typological approach based on similarities of characteristics even though there are some oddities.

        He reviews the classifications according to aetiopathogenesis, endophenotypes, course of the illness, therapeutic response and so on. Again, he proposes a systematic approach based on: a) the spontaneous course of the illness and its therapeutic response; b) the identification of causal factors; and c) the clinician’s ability to assess the syndromatic state with reliability. I agree with him when he says that there is a "final common pathway that lead from the multiple conditioning factors to the uniform clinical syndrome."

        Multivariate statistical methods, interrater reliability and correlation with neurobiological parameters are spelled out. Since Bonhoeffer discovered that different somatic causes can give rise to the same psychopathological symptoms and that the same cause can give rise to similar psychopathological symptoms and since Bayle's discovery of the etiology of GPI we cannot longer call the endogenous psychoses functional psychoses and the former organic psychoses.

        The issue of co-morbidity and syndromatic changes in the course of decades of illness confounds our diagnoses in the long run as has been shown not only for schizophrenia but also for chronic major depression refractory to current therapies. The author supports the dichotomy view of L. F. Sangstad who is quoted along with several of his papers in particular in his last publication of 2008.

        I noticed that Professor Möller does not support the anti-Kraepelinian stance arising since the time of Griesinger, Wernicke, Leonhard and, specific to my point of view, Kleist (1953) nor does he elaborate on K. Schneider's classification. He seems to look for the anatomopathological basis in the context of genetic or molecular biological changes. The upsurge of dimensional trends led to the diagnosis of spectrum disorders which has blurred the once clear-cut boundaries of the major psychotic disorders.



Kleist, K. Die Gliederung der neuropsychiatrischen Erkrankungen. Msch. Psychiat. Neurol. 1953; 725: 539-544.

Möller HJ. Systematic of psychiatric disorders between categorical and dimensional approaches: Kraepelin's dichotomy and beyond. Eur Arch Psychiatry Clin Neurosci. 2008; 258 (Suppl 2):48-73.

Sangstad LF. What is a psychosis and where is it located? Eur Arch Psychiatry Clin Neurosci. 2008; 258 Suppl 2:111-7.

Stengel E. Classification of Mental Disorders. Bull World Health Organ. 1959; 21:601-63.


February 27, 2020