Psychological Medicine

Original Articles

Evidence for a persistent, environment-dependent and deteriorating subtype of subclinical psychotic experiences: a 6-year longitudinal general population study

J. T. W. Wigmana1 c1, R. van Winkela2, Q. A. W. Raaijmakersa3, J. Ormela4, F. C. Verhulsta5, S. A. Reijnevelda6, J. van Osa2a7 and W. A. M. Vollebergha1

a1 Department of Interdisciplinary Social Science, University of Utrecht, The Netherlands

a2 Department of Psychiatry and Psychology, School of Mental Health and Neuroscience, Maastricht University Medical Center, The Netherlands

a3 Research Center for Adolescent Development, University of Utrecht, The Netherlands

a4 Department of Psychiatry, University of Groningen, The Netherlands

a5 Department of Child and Adolescent Psychiatry, Erasmus University Medical Center of Rotterdam, The Netherlands

a6 Department of Health Sciences, University Medical Center Groningen, University of Groningen, The Netherlands

a7 King's College London, King's Health Partners, Department of Psychosis Studies, Institute of Psychiatry, London, UK

Abstract

Background Research suggests that subclinical psychotic experiences during adolescence represent the behavioral expression of liability for psychosis. Little is known, however, about the longitudinal trajectory of liability in general population samples.

Method Growth mixture modeling was used to examine longitudinal trajectories of self-reported positive psychotic experiences in the Youth Self Report (YSR), completed three times over a period of 6 years by a general population cohort of adolescents aged 10–11 years at baseline (n=2230).

Results Four groups with distinct developmental trajectories of low, decreasing, increasing and persistent levels of mild positive psychotic experiences were revealed. The persistent trajectory was associated strongly with cannabis use, childhood trauma, developmental problems and ethnic minority status, and consistently displayed strong associations with factors known to predict transition from subclinical psychotic experience to clinical psychotic disorder (severity of and secondary distress due to psychotic experiences, social and attentional problems and affective dysregulation) and also with high levels of parental-reported psychotic experiences and use of mental health care at the end of the follow-up period. Progressively weaker associations were found for the increasing, decreasing and low trajectories respectively.

Conclusions The results suggest that the outcome of early developmental deviation associated with later expression of psychotic experiences is contingent on the degree of later interaction with environmental risks inducing, first, persistence of psychotic experiences and, second, progression to onset of need for care and service use. Insight into the longitudinal dynamics of risk states in representative samples may contribute to the development of targeted early intervention in psychosis.

(Received August 21 2010)

(Revised February 07 2011)

(Accepted February 07 2011)

(Online publication April 11 2011)

Correspondence

c1 Address for correspondence: J. T. W. Wigman, M.Sc., Department of Interdisciplinary Social Science, Faculty of Social and Behavioral Sciences, University of Utrecht, PO Box 80.140, Heidelberglaan 2, 3508 TC Utrecht, The Netherlands. (Email: J.T.W.Wigman@uu.nl)

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