Psychological Medicine

Original Articles

Emotional and behavioural antecedents of young adults who screen positive for non-affective psychosis: a 21-year birth cohort study

J. Welhama1, J. Scotta2a3, G. Williamsa4, J. Najmana4, W. Bora5, M. O'Callaghana4 and J. McGratha1a2a6 c1

a1 Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, Queensland, Australia

a2 Department of Psychiatry, University of Queensland, St Lucia, Queensland, Australia

a3 Child and Youth Mental Health Service, Royal Children's Hospital, Herston, Queensland, Australia

a4 School of Population Health, University of Queensland, Herston, Queensland, Australia

a5 Mater Children's Hospital, South Brisbane, Queensland, Australia

a6 Queensland Brain Institute, University of Queensland, Queensland, Australia


Background Birth cohort studies have shown that individuals who develop non-affective psychoses display subtle deviations in behaviour during childhood and adolescence. We had the opportunity to examine the widely used Child Behavior Checklist (CBCL) and the Youth Self-Report (YSR) to explore the antecedents of non-affective psychosis.

Method Based on a birth cohort of 3801 young adults, psychopathology was assessed at years 5 and 14 using the CBCL and/or the YSR. Screen-positive non-affective psychosis (SP-NAP) was assessed at year 21 by using the Composite International Diagnostic Interview (CIDI) or a self-report checklist. The association between childhood symptoms and SP-NAP was examined using logistic regression.

Results Of the cohort, 60 subjects were classified as SP-NAP. In males, SP-NAP was associated with higher scores: (a) on year 5 CBCL ‘Total’, ‘Aggression’ and ‘Social, Attention and Thought’ scores; (b) on year 14 CBCL ‘Social’, ‘Attention’ and ‘Delinquency’ scores, and (c) YSR ‘Total’ and many YSR subscores. These associations were less clear for females. Hallucinations at year 14 were associated with SP-NAP for both sexes. Boys with high ‘Total’ scores at both years 5 and 14 were at greatest risk of SP-NAP (a 5-fold risk), followed by boys and girls whose ‘Social, Attention and Thought’ scores either increased or remained high from years 5 to 14 (3- to 13-fold risk).

Conclusions Individuals who screen positive for non-affective psychosis show increased psychopathology during childhood and adolescence. The psychopathological trajectory of children who go on to develop schizophrenia anticipates the heterogeneity associated with the full clinical syndrome.

(Received December 17 2007)

(Revised March 25 2008)

(Accepted May 08 2008)

(Online publication July 08 2008)


c1 Author for correspondence: Professor J. McGrath, Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, Queensland 4076, Australia. (Email: