Top-down or bottom-up: Contrasting perspectives on psychiatric diagnoses

Review

(2486) Views  (681) Full article downloads

Authors: Willem MA Verhoeven, Siegfried Tuinier, Ineke van der Burgt

Published Date September 2008 Volume 2008:2(3) Pages 409 - 417

DOI: http://dx.doi.org/10.2147/BTT.S3053

Willem MA Verhoeven^1,2, Siegfried Tuinier¹, Ineke van der Burgt³

¹Vincent van Gogh Institute for Psychiatry, Venray, The Netherlands; ²Department of Psychiatry, Erasmus University Medical Centre, Rotterdam, The Netherlands; ³Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands

Abstract: Clinical psychiatry is confronted with the expanding knowledge of medical genetics. Most of the research into the genetic underpinnings of major mental disorders as described in the categorical taxonomies, however, did reveal linkage with a variety of chromosomes. This heterogeneity of results is most probably due to the assumption that the nosological categories as used in these studies are disease entities with clear boundaries. If the reverse way of looking, the so-called bottom-up approach, is applied, it becomes clear that genetic abnormalities are in most cases not associated with a single psychiatric disorder but with a certain probability to develop a variety of aspecific psychiatric symptoms. The adequacy of the categorical taxonomy, the so-called top-down approach, seems to be inversely related to the amount of empirical etiological data. This is illustrated by four rather prevalent genetic syndromes, fragile X syndrome, Prader-Willi syndrome, 22q11 deletion syndrome, and Noonan syndrome, as well as by some cases with rare chromosomal abnormalities. From these examples, it becomes clear that psychotic symptoms as well as mood, anxiety, and autistic features can be found in a great variety of different genetic syndromes. A psychiatric phenotype exists, but comprises, apart from the chance to present several psychiatric symptoms, all elements from developmental, neurocognitive, and physical characteristics.

Keywords: genetic disorders, psychiatric symptoms, phenotype, mental disorders

Other articles by Professor Willem M.A. Verhoeven