Thomas A. Ban: Peralta, Cuesta and their associates’ findings on the higher familiality of Leonhard’s classification in polynosologic study
Ernst Franzek´s response to Victor Peralta´s reply to his comment
I agree with Victor Peralta that the historical perspective presented by Thomas A. Ban provides a rare and precious opportunity for revisiting Leonhard’s classification and its far-reaching implications for research in endogenous psychosis.
Peralta´s findings that systematic schizophrenias have more familial aggregation than unsystematic schizophrenias are at odds with the findings of Leonhard and some of his followers. One reason that could explain this disagreement is that Peralta conducted a study with multiple affected families. His argument that high density family studies are more powerful means than common family studies for detecting familial/genetic underpinnings is right. These studies provide much higher statistical power.
The twin study by Franzek and Beckmann (1998) is based on hospital registers, this is also right. However, it has to be mentioned that the aim of this twin study was to differentiate genetic loading between cycloid psychosis and the schizophrenic group as a whole. The twin study does not provide any data that could distinguish unsystematic and systematic schizophrenia. There were no monozygotic twins suffering from systematic schizophrenia found in the whole twin sample. The main object of this twin study, therefore, is on the genetic distinction of cycloid psychoses and unsystematic schizophrenia: low genetic loading in cycloid psychoses and high genetic loading in unsystematic schizophrenia. The lack of monozygotic twins with systematic schizophrenia in the study sample has been discussed in detail elsewhere (Franzek and Beckmann 1999).
I agree with Peralta that the higher familial aggregation of unsystematic schizophrenias than systematic schizophrenias has been consistently demonstrated only for the unsystematic subtype of periodic catatonia.
The diagnostic procedures in the study of Peralta et al, compared to the twin study of Franzek and Beckmann, did not differ. In both groups the diagnoses were blindly performed regarding subject identity. Peralta described, therefore, an adequate diagnostic procedure for Leonhard´s system.
Very interesting are Peralta´s findings that out of his 1,094 affected subjects almost 20% had never been hospitalized and even 6 % had never been under psychiatric care. This is in line with the statement that systematic schizophrenic disorders are brain diseases affecting functional brain systems with different heaviness (Franzek and Musalek 2011).
I fully agree with Peralta´s findings on antipsychotic treatment response. Unsystematic schizophrenic patients, in particular affect laden paraphrenia, show a significantly better response to antipsychotic treatment compared to the systematic schizophrenic group.
Additionally, I would like to state at this point that my clinical experience during the last 15 years is that many systematic schizophrenic patients (according to Leonhard´s system) are allocated to the autistic spectrum according to the DSM.
Finally, I would like to congratulate Peralta for his excellent paper and it would be great to do some investigations on the complexity of brain systems together based on a differentiated psychopathology.
Franzek E, Beckmann H. Different genetic background of schizophrenia spectrum psychoses: a twin study. Am J Psychiatry. 1998, 155:76-83.
Franzek E, Beckmann H. Psychoses of the Schizophrenic Spectrum in Twins. A discussion on the nature – nurture debate in the etiology of “endogenous” psychoses. Springer, Wien New York, 1999.
Franzek E, Musalek M. Advances in psychopathology, classification and diagnosis of psychosis and its clinical implications. Minerva Psichiatrica 2011, 52: 171-185.
December 8, 2016