Reducing the Risk for Postpartum Depression in Adolescent Mothers A Randomized Controlled Trial

OBJECTIVE: To estimate the effect of an interpersonal therapy-based intervention on reducing the risk of postpartum depression in adolescents. METHODS: A randomized controlled trial enrolled 250 pregnant adolescents who were aged 18 years or younger at conception. The initial sample size calculation estimated 276 participants (324 with attrition) were needed to detect a 50% reduction in risk of the primary outcome, postpartum major depressive episode, with an alpha of 0.05% and 80% power. An interim analysis by the Data Safety and Monitoring Committee informed a revision in the sample size target to 250. Participants were randomized to the intervention (n=129) or a time-matched control group (n=121) who attended sessions about pregnancy topics. Each group received five prenatal sessions and a postpartum booster session. A structured diagnostic interview was administered at baseline and specific time points through 12-months postpartum to assess for major depressive episode onset. RESULTS: Participants were recruited from December 2011 to May 2016 through urban prenatal care sites in the state of Rhode Island. Of the 250 participants, 58% identified as Hispanic and 20% as black or African American. The rate of major depressive episode by 12 months postpartum was 7.0% (95% CI 2.3-11.7%) in the control group and 7.6% (95% CI 2.5-12.7%) in the intervention group, with no significant difference between groups at any time point (P=.88 by log-rank test). CONCLUSION: No benefit was shown between the intervention and control groups in the rates of major depressive episode, which is likely related to a lower than predicted rate of this outcome in the control group (7.6% actual vs 25% predicted). Enhanced local community resources available to pregnant and parenting adolescents during the study period may be an explanation for this result.