Socioeconomic status and risk of psychological distress and depression in the Stockholm Public Health Cohort: A population-based study

Background: There is limited evidence whether the association between low socioeconomic status and risk of common mental disorders varies with symptom severity, type of socioeconomic indicator or gender. Methods: A population-based survey was conducted among a random sample of Stockholm County residents aged 18-84 years in 2002. Respondents were reassessed via a follow-up questionnaire in 2007. Participants in both surveys (n = 23794) were categorized according to socioeconomic status at baseline and followed up for onset of psychological distress (according to the twelve-item general health questionnaire) and depression (according to health data registers). Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Occupational class was not associated with risk of psychological distress, regardless of severity or gender. Occupational class was strongly associated with onset of depression in men (OR 3.0 [95% CI 1.5-5.9], comparing unskilled manual workers with higher non-manual workers) but not women. Income was associated with risk of onset of all outcomes, and risks increased with symptom severity. Belonging to the highest household income category was particularly protective of depression in women. Education was unrelated to either outcome in men and women overall. Limitations: Retention rate at follow-up was 76% and depression was ascertained via health service use. Conclusion: Low socioeconomic position is associated with onset of depression but not mild distress. Attributes of occupational class and household income may be respectively more relevant for the development of depression in men and women. (C) 2011 Elsevier B.V. All rights reserved.