Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-22T08:19:32.519Z Has data issue: false hasContentIssue false

Is the earlier age at onset of schizophrenia in males a confounded finding?

Results from a cross-cultural investigation

Published online by Cambridge University Press:  03 January 2018

Assen Jablensky*
Affiliation:
Department of Psychiatry and Behavioural Science, University of Western Australia
Steven W. Cole
Affiliation:
Department of Health Psychology, University of California, Los Angeles, CA 90024-1563, USA
*
Professor A. Jablensky, UDP, Medical Research Foundation Building, 50 Murray Street, Perth, WA 6000, Australia

Abstract

Background

The finding of an earlier age at onset of schizophrenia in males compared with females, replicated across a number of studies, appears to be so robust as to support hypotheses about gender differences in the aetiology of the disorder. However, the possibility that this observed gender effect might reflect other confounding variables has not been adequately explored.

Method

We analysed data on 778 men and 653 women, in three developing countries and in seven developed countries, who had been assessed in the WHO 10-country study of schizophrenia. We applied a generalised linear modelling strategy to estimate the unconfounded contributions of gender, family history, premorbid personality and marital status to age at onset.

Results

The model that explained the highest percentage of the total variance indicated strong main effects (P < 0.001) for marital status and premorbid personality, a weak effect for family history, and an attenuated effect for gender. Two independent verification procedures suggested an independent onset-delaying effect for marital status (married), more marked in males.

Conclusions

The gender difference in the age at onset of schizophrenia is not a robust biological characteristic of the disorder. Failure to control for marital status and premorbid personality in male/ female comparisons of age at onset may explain a large part of the differences reported previously.

Type
Papers
Copyright
Copyright © 1997 The Royal College of Psychiatrists 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Angermeyer, M. C. & Kühn, L. (1988) Gender differences in age at onset in schizophrenia. European Archives of Psychiatry and Neurological Sciences. 237, 351364.Google Scholar
Bleuler, E. (1911) Dementia Praecox oder die Gruppe der Schizophrenien. Leipzig: Deuticke.Google Scholar
Bullmore, E., Brammer, M., Harvey, I., et al (1995) Cerebral hemispheric asymmetry revistted; effects of handedness, gender and schizophrenia measured by radius of gyration in megnetic resonance images. Psychological Medicine. 25, 349363.Google Scholar
Castle, D. J. & Murray, R. M. (1991) The neuro developmental basis of sex differences in schizophrenia. Psychological Medicine. 21, 565575.CrossRefGoogle Scholar
Da Lisi, L. E. (1992) The significance of age of onset for schizophrenia. Schizophrenia Bulletin, 18, 209215.Google Scholar
Faraona, S. V., Chen, W. J., Goldstain, J. M., et al (1994) Gender differences in age onset of schizophrenia. British Journal of Psychiatry. 164, 625629.Google Scholar
Folnegovic, Z. & Foinegovic-$Snmalc, V. (1994) Schizophrenia in Croatia: age of onset differences between males and fennales. Schizophrenia Research. 14, 8391.CrossRefGoogle Scholar
Goldstain, J. M., Faraona, S. V., Chan, W. J. et al (1992) Gender and the familial risk for schizophrenia. Disentangling confounding factors. Schizophrenia Research. 7, 135140.CrossRefGoogle Scholar
Hägner, H., Bahrans, S., De Vry, J., et al (1991) Oestradiol enhances the vulnerability threshold for schizophrenia in women by an early effect on dopaminergic neurotransmission. Evidence from an epidemiological study and from animal experiments. European Archives of Psychiatry and Clinical Neumscience. 241, 6568.Google Scholar
Hägner, H., Bahrans, S., De Vry, J., Riachar-Rössler, A., an dar Haiden, W., et al (1993) Generating and testing a causal explanation of the gender difference in age at first onset of schizophrenia. Psychological Medicine. 23, 925940.Google Scholar
Jablensky, A., Sartorius, N., Ernbarg, G., et al (1992) Schizophrenia: Manifestations, Incidence and Course in Different Cultures. A World Health Organization Ten-Country Study. Psychological Medicine Monograph Supplement 20. Cambridge: Cambridge University Press.Google Scholar
Jönsson, S. A. T. & Jonsson, H. (1992) Outcome in untreated schizophrenia: search for symptoms and traits with prognostic meaning in patients admitted to a mental hospital in the preneuroleptic era. Acta Psychiatrica Scandinavica, 85, 313320.Google Scholar
Kandler, K. S. & Walsh, D. (1995) Gender and schizophrenia, Results of an epidemiologically-based family study. British Journal of Psychiatry, 167.184192.CrossRefGoogle Scholar
Kraapelin, E. (1909) Psychiatrie. 8. Aufl. Bd II: Klinische Psychiatrie. Leipzig: Barth.Google Scholar
Lorangar, A. W. (1984) Sex difference in age at onset of schizophrenia. Archives of General Psychiatry, 41, 157161.CrossRefGoogle Scholar
McCullagh, P. & Naldar, J. E. (1989) Generalized Linear Models. 2nd edn. London: Chapman and Hall.Google Scholar
Ødagaard, Ø. (1946) Marriage and mental disease: a study in social psychopathology. journal of Mental Science, 92, 3539.Google Scholar
Shanks, J. & Atkins, P. (1985) Psychiatric patients who noarry each other. Psychological Medicine. 15, 395401.CrossRefGoogle ScholarPubMed
Shimizu, A., Kurachi, M., Noda, M., et al (1988) Influence of sex on age at onset of schizophrenia. Japonese Journal of Psychiatry and Neurology, 42, 3540.Google ScholarPubMed
Wing, J. K., Coopar, J. E. & Sartorius, N. (1974) The Measurement and Classification of Psychiatric Symptoms. London: Cambridge University Press.Google Scholar
World Health Organization (1978) Mental Disorders: Glossary and Guide to their Classification in Accordance with the Ninth Revision of the International Classification of Diseases. Geneva: WHO.Google Scholar
World Health Organization (1979) Schizophrenia. An International Follow-Up Study. Chichester: Wiley Google Scholar
World Health Organization (1992) The Tenth Revision of the International Classification of Diseases and Related Health Problems (ICD-10). Geneva: WHO.Google Scholar
Ziglar, E. & Levina, J. (1981) Age of first hospitalisation of schizophrenics: a developmental approach. Journal of Abnormal Psychohgy 96, 458464.Google Scholar
Submit a response

eLetters

No eLetters have been published for this article.