Thomas A. Ban: In historical perspective: Peralta, Cuesta and their associates’ findings on the highest familiality of Leonhard’s classification in polynosologic study  

Carlos Morra’s comment

I would like to congratulate Peralta, Cuesta and their associates for their report. I agree with Tom Ban concerning the importance of demonstrating that Karl Leonhard’s classification provides more homogenous populations, not only in terms of pharmacological responsiveness, as had been shown by Frank Fish several decades ago, but also, in terms of “familiality”. I do hope their findings that using Leonhard’s classification provided a genetically more homogenous population than current consensus-based classifications and even an empirical classification, will have an impact on molecular genetic research in schizophrenia.

I think Peralta, Cuesta and their associates’ findings provide a strong argument in favor of the contention that “how psychotic disorders are classified have a strong impact on “familailty”. If this is the case, what holds us back in identifying the most homogenous populations in terms of “familiality” instead of embarking blindly on molecular genetic research in mental disorders? In Leonhard’s classification of schizophrenia, both unsystematic schizophrenia and systematic schizophrenia are still widely heterogeneous populations, at least in pharmacological responsiveness. Would it not be desirable to link highly sophisticated molecular genetic research with commensurate research in psychopathology and psychiatric nosology?

I noted that the Peralta and Cuesta’s team used Leonhard’s symptom-catalogue, published in 1990, for classifying patients. I was not familiar with Leonhard’s paper from 1990; however, a diagnostic instrument based on that paper for assigning Leonhardian diagnoses was devised, it would be very useful if it could be rendered accessible.  

Carlos Morra

April 07, 2016