[The resident of Tarnok street 3. deported]

Bertalan Petho passed away in the Spring of 2020. The genius investigator was an enthusiastic and dedicated follower of Karl Leonhard, one of the German psychiatrists, who developed his own nosology which remained largely hidden from broad recognition. Bertalan Petho verified the validity and supplemented the Leonhard nosology: e.g. completed their "premorbid" personality concept and entered some psychosocial criteria in the etiology of the endogenous psychoses. His results and treatises were published in English and German in numerous and renowned periodicals. Summarized studies emerged in books. In light of trauma studies and new research on neurocognitive and epigenetic topics, traditional psychiatric classification seems to lose its validity. On the one hand, transgenerational trauma influences gene expression as an epigenetic factor. On the other hand, it also affects psycho-social development and growth of the individuum. Dimensional diagnostic approaches and non-categorical disease classification appears to be more natural and plausible in the state of science. WKL nosology will remain a part of psychiatry􀀀 s history as well as a wonderful theory with practicality - for the knowledgeable.