a1 School of Psychiatry, University of New South Wales, Sydney, Australia
a2 Institute of Psychiatry, King's College, London, UK
a3 Departments of Psychology and Psychiatry, Washington University in St Louis, USA
a4 University of Maryland School of Medicine, the Maryland Psychiatric Research Center, and the VISN 5 Mental Illness Research, Education and Clinical Center, Baltimore, MD, USA
a5 Harvard University, Cambridge, MA, USA
a6 National Institute of Mental Health, Bethesda, MD, USA
Background The organization of mental disorders into 16 DSM-IV and 10 ICD-10 chapters is complex and based on clinical presentation. We explored the feasibility of a more parsimonious meta-structure based on both risk factors and clinical factors.
Method Most DSM-IV disorders were allocated to one of five clusters as a starting premise. Teams of experts then reviewed the literature to determine within-cluster similarities on 11 predetermined validating criteria. Disorders were included and excluded as determined by the available data. These data are intended to inform the grouping of disorders in the DSM-V and ICD-11 processes.
Results The final clusters were neurocognitive (identified principally by neural substrate abnormalities), neurodevelopmental (identified principally by early and continuing cognitive deficits), psychosis (identified principally by clinical features and biomarkers for information processing deficits), emotional (identified principally by the temperamental antecedent of negative emotionality), and externalizing (identified principally by the temperamental antecedent of disinhibition).
Conclusions Large groups of disorders were found to share risk factors and also clinical picture. There could be advantages for clinical practice, public administration and research from the adoption of such an organizing principle.
(Received May 22 2008)
(Revised May 05 2009)
(Accepted May 12 2009)
(Online publication October 01 2009)