Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

A longitudinal study of premorbid IQ Score and risk of developing schizophrenia, bipolar disorder, severe depression, and other nonaffective psychoses

Zammit, Stanley, Allebeck, Peter, David, Anthony S., Dalman, Christina, Hemmingsson, Tomas, Lundberg, Ingvar and Lewis, Glyn 2004. A longitudinal study of premorbid IQ Score and risk of developing schizophrenia, bipolar disorder, severe depression, and other nonaffective psychoses. Archives of General Psychiatry 61 (4) , pp. 354-360. 10.1001/archpsyc.61.4.354

Full text not available from this repository.

Abstract

Context Longitudinal studies indicate that a lower IQ score increases risk of schizophrenia. Preliminary evidence suggests there is no such effect for nonpsychotic bipolar disorder. To our knowledge, there are no prior population-based, longitudinal studies of premorbid IQ score and risk of developing severe depression requiring hospital admission. Objectives To investigate the association between premorbid IQ score and risk of developing schizophrenia, other nonaffective psychoses, bipolar disorder, and severe depression and to investigate effects of confounding and examine possible causal pathways by which IQ may alter these risks. Design Historical cohort study, using record linkage for hospital admissions during a 27-year follow-up period. Setting Survey of Swedish conscripts (1969-1970). Participants Population-based sample of 50 087 male subjects. Data were available on IQ score at conscription and on other social and psychological characteristics. Main Outcome Measures International Classification of Diseases, Eighth Revision or Ninth Revision diagnoses of schizophrenia, bipolar disorder, severe depression, and other nonaffective psychoses. Results There was no association between premorbid IQ score and risk of bipolar disorder. Lower IQ was associated with increased risk of schizophrenia, severe depression, and other nonaffective psychoses. Risk of schizophrenia was increased in subjects with average IQ compared with those with high scores, indicating that risk is spread across the whole IQ range. Conclusions Lower IQ score was associated with increased risk for schizophrenia, severe depression, and other nonaffective psychoses, but not bipolar disorder. This finding indicates that at least some aspects of the neurodevelopmental etiology of bipolar disorder may differ from these other disorders.

Item Type: Article
Date Type: Publication
Status: Published
Schools: MRC Centre for Neuropsychiatric Genetics and Genomics (CNGG)
Medicine
Subjects: R Medicine > R Medicine (General)
Publisher: JAMA
ISSN: 0003-990X
Last Modified: 17 Oct 2019 12:50
URI: http://orca.cf.ac.uk/id/eprint/615

Citation Data

Cited 278 times in Google Scholar. View in Google Scholar

Cited 311 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item