Psychological Medicine

Invited Review

A systematic review and meta-analysis of the psychosis continuum: evidence for a psychosis proneness–persistence–impairment model of psychotic disorder

J. van Osa1a2 c1, R. J. Linscotta1a3, I. Myin-Germeysa1, P. Delespaula1 and L. Krabbendama1

a1 Department of Psychiatry and Neuropsychology, South Limburg Mental Health Research and Teaching Network, EURON, Maastricht University, Maastricht, The Netherlands

a2 Division of Psychological Medicine, Institute of Psychiatry, London, UK

a3 Department of Psychology, University of Otago, Dunedin, New Zealand

Abstract

A systematic review of all reported incidence and prevalence studies of population rates of subclinical psychotic experiences reveals a median prevalence rate of around 5% and a median incidence rate of around 3%. A meta-analysis of risk factors reveals associations with developmental stage, child and adult social adversity, psychoactive drug use, and also male sex and migrant status. The small difference between prevalence and incidence rates, together with data from follow-up studies, indicates that approximately 75–90% of developmental psychotic experiences are transitory and disappear over time. There is evidence, however, that transitory developmental expression of psychosis (psychosis proneness) may become abnormally persistent (persistence) and subsequently clinically relevant (impairment), depending on the degree of environmental risk the person is additionally exposed to. The psychosis proneness–persistence–impairment model considers genetic background factors impacting on a broadly distributed and transitory population expression of psychosis during development, poor prognosis of which, in terms of persistence and clinical need, is predicted by environmental exposure interacting with genetic risk.

(Received November 12 2007)

(Revised May 12 2008)

(Accepted May 12 2008)

(Online publication July 08 2008)

Correspondence

c1 Address for correspondence: Dr J. van Os, Department of Psychiatry and Neuropsychology, South Limburg Mental Health Research and Teaching Network, EURON, Maastricht University, PO Box 616 (DRT 10), 6200 MD Maastricht, The Netherlands. (Email: j.vanos@sp.unimaas.nl)

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