Objective: This study reports the 12-month prevalence of major depressive episode and its risk factors in a representative nationwide sample.
Method: A random sample of non-institutionalized Finnish individuals aged 15-75 years (N = 5993) was interviewed in 1996. Major depressive episode during the last 12 months was assessed using the Short Form of the University of Michigan version of the Composite International Diagnostic Interview (the UM-CIDI Short Form).
Results: The population prevalence of major depressive episode was 9.3% [95% CI 8.5,10.0], and the age-adjusted prevalences for females and males were 10.9% [95% CI 9.7,12.0] and 7.2 [95% CI 6.2,8.2], respectively. In logistic regression analyses the factors associated with major depressive episode after adjustment for age were urban residency, smoking, alcohol intoxication and chronic medical conditions. In addition, being single and obese were found to be risk factors for males.
Conclusion: The female to male risk ratio for major depressive episode was smaller than in many previous studies. The sex-specific risk factor associations warrant further investigation into sex differences in depression.