Schizophrenia risk factors constitute general risk factors for psychiatric symptoms in the population

Breetvelt, Elemi J.; Boks, Marco P.M.; Numans, Mattijs E.; Selten, Jean-Paul; Sommer, Iris E.C.; Grobbee, Diederick E.; Kahn, René S.; Geerlings, Mirjam I.

doi:10.1016/j.schres.2010.03.033

« Previous Next »Schizophrenia Research
Volume 120, Issue 1 , Pages 184-190, July 2010

Schizophrenia risk factors constitute general risk factors for psychiatric symptoms in the population

Elemi J. Breetvelt
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
- Corresponding author. UMC-Utrecht, Heidelberglaan 100, 3584 CX Utrecht, PO. Box 85500, 3508 GA Utrecht, HP: B01.206, The Netherlands. Tel.: +31 88 75 56370; fax: +31 88 75 55509.
Marco P.M. Boks
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
Mattijs E. Numans
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
Jean-Paul Selten
- GGZ Leiden en omstreken, The Netherlands
Iris E.C. Sommer
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands
Diederick E. Grobbee
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
René S. Kahn
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands
Mirjam I. Geerlings
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands

Received 17 November 2009; received in revised form 17 March 2010; accepted 28 March 2010. published online 26 April 2010.

Abstract

Background

The presence of a psychosis continuum is suggested by studies showing that schizophrenia and non-clinical psychotic symptoms in the general population share the same risk factors. However, to our knowledge no large-scale studies have been conducted which examine the specificity of these risk factors in the general population.

Aim

To investigate whether socio-demographic characteristics associated with non-clinical psychotic symptoms are also associated with other psychiatric symptoms. And secondly, to examine to what extent concomitant psychiatric symptoms explain the relationship between socio-demographic characteristics and non-clinical psychotic symptoms.

Methods

In a general population sample of 4894 subjects (mean age 39years, 45% men) from the Utrecht Health Project we investigated the associations of socio-demographical characteristics with non-clinical psychotic symptoms and other psychiatric symptoms by using the SCL-90. We examined these associations using multivariable logistic regression analyses with and without controlling for the presence of other psychiatric symptoms.

Results

Participants with non-clinical psychotic symptoms had an 89% probability of concomitant depressive, anxiety or phobic anxiety symptoms, compared to 11% in participants without psychotic symptoms. The risk profiles for non-clinical psychotic symptoms and other psychiatric symptoms were largely similar. Non-Dutch ethnicity was most strongly associated with non-clinical psychotic symptoms. Adjusting for other psychiatric symptoms did not increase the specificity of the risk factors.

Conclusion

Socio-demographic risk factors for non-clinical psychotic symptoms in the general population are also risk factors for other psychiatric symptoms. The relationship between these risk factors and psychotic symptoms are for a substantial part explained by an increase in other psychiatric symptoms.

Keywords: Schizophrenia, General population, Psychotic symptoms, Risk factors, SCL-90