Open Access Research article

Development of mental disorders one year after exposure to psychosocial stressors; a cohort study in primary care patients with a physical complaint

Lilli Herzig1*, Nicole Mühlemann1, Bernard Burnand3, Bernard Favrat4, Nader Haftgoli1, François Verdon1, Thomas Bischoff1 and Paul Vaucher12

Author Affiliations

1 Institute of General Medicine, University of Lausanne, Rue du Bugnon 44, Lausanne 1011, Switzerland

2 Department of Health and Community Medicine, University of Geneva, Michel-Servet 1, Geneva, 1211, Switzerland

3 Institute of Social and Preventive Medicine, University of Lausanne, Route de la Corniche 2, Epalinges, 1066, Switzerland

4 Department of Ambulatory Care and Community Medicine, University of Lausanne Rue du Bugnon 44, Lausanne, 1011, Switzerland

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BMC Psychiatry 2012, 12:120  doi:10.1186/1471-244X-12-120

Published: 20 August 2012

Abstract

Background

Mental disorders, common in primary care, are often associated with physical complaints. While exposure to psychosocial stressors and development or presence of principal mental disorders (i.e. depression, anxiety and somatoform disorders defined as multisomatoforme disorders) is commonly correlated, temporal association remains unproven. The study explores the onset of such disorders after exposure to psychosocial stressors in a cohort of primary care patients with at least one physical symptom.

Method

The cohort study SODA (SOmatization, Depression and Anxiety) was conducted by 21 private-practice GPs and three fellow physicians in a Swiss academic primary care centre. GPs included patients via randomized daily identifiers. Depression, anxiety or somatoform disorders were identified by the full Patient Health Questionnaire (PHQ), a validated procedure to identify mental disorders based on DSM-IV criteria. The PHQ was also used to investigate exposure to psychosocial stressors (before the index consultation and during follow up) and the onset of principal mental disorders after one year of follow up.

Results

From November 2004 to July 2005, 1020 patients were screened for inclusion. 627 were eligible and 482 completed the PHQ one year later and were included in the analysis (77%). At one year, prevalence of principal mental disorders was 30/153 (19.6% CI95% 13.6; 26.8) for those initially exposed to a major psychosocial stressor and 26/329 (7.9% CI95% 5.2; 11.4) for those not. Stronger association exists between psychosocial stressors and depression (RR = 2.4) or anxiety (RR = 3.5) than multisomatoforme disorders (RR = 1.8). Patients who are “bothered a lot” (subjective distress) by a stressor are therefore 2.5 times (CI95% 1.5; 4.0) more likely to experience a mental disorder at one year. A history of psychiatric comorbidities or psychological treatment was not a confounding factor for developing a principal mental disorder after exposure to psychosocial stressors.

Conclusion

This primary care study shows that patients with physical complaints exposed to psychosocial stressors had a higher risk for developing mental disorders one year later. This temporal association opens the field for further research in preventive care for mental diseases in primary care patients.

Keywords:
Primary health care; Longitudinal studies; Mental disorder; Psychosocial deprivation; Stress