The epidemiology of major depression: implications of occurrence, recurrence, and stress in a Canadian community sample.

OBJECTIVE

To study the effects of stress process variables on the prevalence of major depressive disorder (MDD) and to explore the factors related to its onset and recurrence, using measures of stress and disorder that are more comprehensive than those in previous studies of depression.

METHOD

Data were collected from a randomly selected community sample of 1393 adult respondents in Toronto, Ontario. Depression was measured using the Composite International Diagnostic Interview (CIDI).

RESULTS

Bivariate and multivariate analyses examine demographic and stress process correlates of MDD to assess their impact on both occurrence and recurrence. The effects of childhood experiences on lifetime MDD are examined as risk factors for the initial onset of depression. With respect to occurrence, the multivariate analyses tended to show agreement with established findings. Results using a subsample of people with lifetime depression to predict recurrence tended to mirror results using the full sample, except with respect to gender, birthplace, and, to a certain degree, stress differences. Finally, traumas experienced in childhood, as well as early childhood experiences involving parental substance abuse and mental health problems, were significant predictors of the onset of major depressive disorder.

CONCLUSION

This research currently represents the only Canadian community study to examine the relationship between stress, social support, coping, and depression using outcome measures that approximate Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria. In addition, it is among the few that use a comprehensive measure of life stress encompassing childhood experiences and current operant stress (both events and chronic problems).