Background: Although minor depressive disorder is of considerable clinical and public health importance, it has received limited research attention relative to major depressive disorder. This study examines the incidence rate and relative risk for minor depressive disorder following miscarriage.
Methods: Using a cohort design we tested whether miscarrying women are at increased risk for an episode of minor depression (diagnosed based on research criteria proposed in Appendix B of DSM-IV) in the 6 months following loss. The miscarriage cohort consisted of women attending a medical center for spontaneous abortion (n=229); the comparison group was a population-based cohort of women drawn from the community (n=230).
Results: Among miscarrying women, 5.2% experienced an episode of minor depression, compared with 1.0% of community women. The overall relative risk for an episode of minor depression for miscarrying women was 5.2 (95% confidence interval, 1.2-23.6). Relative risk did not vary by length of gestation at the time of loss or attitude toward the pregnancy. The majority of episodes in miscarrying women began within 1 month following loss.
Limitations: Minor depression was relatively rare in both study cohorts. The resulting limits on statistical power reduced our ability to identify factors, such as sociodemographic or reproductive history variables that might moderate the effect of miscarriage on risk for minor depression.
Conclusions: These results, in the context of prior work showing increased risks of major depression and depressive symptoms following miscarriage, lend some support to the conceptualization of minor depressive disorder as part of a continuum of symptom severity. Miscarrying women should be evaluated for depression at their follow-up medical visits.