Understanding putative risk factors for schizophrenia: retropective and prospective studies

Understanding putative risk factors for schizophrenia: retropective and prospective studies

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J Psychiatry Neurosci 2006;30(5):342-348

Suzanne King, PhD; David Laplante, PhD; Ridha Joober, MD, PhD

King, Laplante, Joober — Douglas Hospital Research Centre, Borough of Verdun, Montréal, Que.; King, Joober — Department of Psychiatry, McGill University, Montréal, Que.

Abstract

This paper describes a research program intended to provide a better understanding of the influence of several putative risk factors for schizophrenia on child development and psychosis. Two related components of the overall program are described: the retrospective EnviroGen projects, which use a variety of putative risk factors to explain variance in several dimensions of schizophrenia and in psychotic symptoms in community controls, and Project Ice Storm, which prospectively examines the effects of prenatal maternal stress in the children of women who were exposed to the 1998 Quebec ice storm during their pregnancies. The EnviroGen projects have been successful in explaining variance in several dimensions of illness, including premorbid adjustment and severity of dissociative symptoms. Project Ice Storm has demonstrated the noxious effects of prenatal stress on cognitive and language development in children. We have also found that “ice storm children” exposed in specific weeks of gestation show greater dermatoglyphic asymmetry, as has been reported for samples of patients with schizophrenia. In both studies, prenatal maternal stress has been associated with more severe childhood behaviour problems. The combination of retrospective and prospective studies is a rich source of triangulated results providing information about developmental psychopathology.

Résumé

Cette communication décrit un programme de recherche qui vise à faire mieux comprendre l’influence de plusieurs facteurs présumés de risque de schizophrénie sur le développement de l’enfant et la psychose. On décrit deux éléments constituants connexes du programme global : les projets EnviroGen rétrospectifs qui utilisent un éventail de facteurs présumés de risque pour expliquer la variation de plusieurs dimensions de la schizophrénie et des symptômes psychotiques chez des témoins communautaires, et le projet Tempête de verglas dans le cadre duquel on examine de façon prospective les effets du stress prénatal de la mère sur les enfants de femmes exposées à la tempête de verglas de 1998 qui a frappé le Québec pendant leur grossesse. Les projets EnviroGen ont réussi à expliquer la variation de plusieurs dimensions de la maladie, y compris l’adaptation prémorbide et la sévérité des symptômes de dissociation. Le projet Tempête de verglas a démontré les effets nocifs du stress prénatal sur le développement de la cognition et du langage chez les enfants. Nous avons aussi constaté que les «enfants de la tempête de verglas» exposés au cours de semaines précises de la gestation montrent une plus grande asymétrie dermatoglyphique comme on l’a signalé chez les échantillons de patients atteints de schizophrénie. Dans les deux études, on a établi un lien entre le stress prénatal chez la mère et des problèmes comportementaux plus sévères chez l’enfant. La combinaison d’études rétrospectives et prospectives constitue une riche source de résultats triangulaires qui produisent de l’information sur la psychopathologie du développement.


Medical subject headings: anorexia nervosa; bulimia nervosa; genetics; environment.

Submitted Feb. 17, 2005; Revised June 22, 2005; Accepted July 4, 2005

Acknowledgements: We thank all of the research assistants, interviewers and students who have worked on the EnviroGen and Ice Storm projects, as well as the subjects who have graciously participated. Dr. King’s work has been supported by research fellowships from the Fonds de recherche en santé du Québec (FRSQ). The EnviroGen project has been funded by grants to Dr. King from the FRSQ and from the Schizophrenia Axis of the FRSQ Mental Health Network. Project Ice Storm has been supported by grants from the McGill University Stairs Memorial Fund, the Canadian Psychiatric Research Foundation, and the Canadian Institutes of Health Research to Dr. King and by a grant from the Schizophrenia Axis of the FRSQ Mental Health Network to Dr. Laplante.

Competing interests: None declared.

Contributors: Dr. King conceived of and designed the study and acquired and analyzed data. Dr. Laplante collected and analyzed data for Project Ice Storm. Drs. King and Joober drafted and revised the article. All authors approved the final version to be published.

Correspondence to: Dr. Suzanne King, Douglas Hospital Research Centre, 6875 LaSalle Blvd., Borough of Verdun, Montréal QC H4H 1R3; fax 514 762-3049; suzanne.king@douglas.mcgill.ca