The depression and marital status relationship is modified by both age and gender.

Background: Marital status is associated with major depression prevalence, however, the strength of association may be modified by age and gender.

Methods: The data sources were a series of cross sectional national health surveys of the Canadian population carried out by Statistics Canada during 1996-2013. These were cross-sectional files from the National Population Health Survey of 1996, together with the Canadian Community Health Surveys from 2000 to 2013; the respondents were 18 years and older. The data was analyzed with meta-analytic techniques and logistic regression.

Results: In terms of gender, the odds ratios of depression were smaller for females (vs males) who were single, widowed or separated compared to married people. Regarding age, the odds ratios for depression showed a steady rise with increasing age for those in single and in common-law relationships compared to married people. In contrast the odds ratios for depression declined with age for those widowed, separated and divorced compared to married people. The strength of the interaction terms used to quantify these moderating effects showed no change from 1996 to 2013.

Limitations: Only one member of each household was included, so that relationship issues could not be studied. The generalizability of our findings requires international data. Also the diagnostic interviews used are not as accurate as clinical assessments.

Conclusion: Use of large numbers of participants has revealed some robust modifying effects of both gender and age on the depression/marital status relationship. The clinical significance of our findings is that the vulnerability to development of depression is not only related to marital status, but that this relationship is modified by age and gender.