Incident rates rising for post-partum depression among women, risk factor for suicide

During the six-year surveillance period, 5,267 or 9.9 percent, of active component service women who gave birth for the first time were diagnosed with postpartum depression (PPD) during the 12 months post delivery (postpartum) period, according to the study published in the Medical Surveillance Monthly Report (AFHSC), a peer-reviewed journal on illnesses and diseases affecting service members from the Armed Forces Health Surveillance Center. Among dependent spouses of active component service members, 10,301 or 8.2 percent were diagnosed with PPD.

"Given that approximately 15,000 service women and wives of service men give birth each year in the Department of Defense health system, a full understanding of the common problem of post-partum depression is important for the Military Health System, particularly because of its role as a risk for suicidality," said Army Colonel William Corr, deputy director of the AFHSC's division of Epidemiology and Analysis.

The report summarizes counts, percentages, and trends of incident PPD and suicidality diagnoses during the postpartum period among active component service women and dependent spouses over a six-year surveillance period.

The surveillance period was January 1, 2007 to December 31, 2012. The surveillance population included two cohorts, active component service women of all U.S. military services and dependent spouses of active component service members of all services who gave birth for the first time between January 1, 2007 and December 31, 2011. Females within each cohort were followed for a one-year postpartum period.

For each year in the surveillance period, service women had a higher percentage of PPD, ranging from 9.2 to 10.5 percent with a slightly increasing trend, compared to the percentage for dependent spouses, which remained steady. The mean time intervals from delivery to PPD diagnoses were 122 days (50th percentile: 96 days) for service women and 95.6 days (50th percentile: 54 days) for dependent spouses.

In general, incidence of PPD in the postpartum period among service women was higher in the Army (12.0%) and lower in the Air Force (7.3%) than in any of the other services.

The overall incidence of PPD was higher among younger than older aged service women; the incidence was approximately 40 percent higher among the youngest (18-20 years, 11.9%) compared to the oldest (>40, 8.5%) aged service women. All age groups showed an increasing trend, except for women aged older than 40.

In contrast, the incidence of PPD was lower among the youngest (18-20 years, 7.7%) than any other age group of dependent spouses. All other age groups had steady and similar trends, except for women aged older than 40. Dependent women older than 40 had an increasing trend over the entire surveillance period and for delivery years 2010 and later had the highest incidence rates of PPD compared to all other age groups.

For the multivariate analyses, the odds ratio was adjusted for service, race/ethnicity, age, delivery outcome, and history of mental disorder. Service women with PPD had a higher odds for suicidality compared to service women without PPD (OR=42.2, 95% CI=28.8, 61.9). Risk factors predicting suicidality for service women included service (Coast Guard), age (18-20 years), PPD during the postpartum period, and history of mental disorder diagnosis.

Dependent spouses with PPD also had a higher odds for suicidality compared to dependent spouses without PPD (OR=14.5, 95% CI=10.8, 19.4). Risk factors predicting suicidality for dependent spouses included race/ethnicity (black, non-Hispanic), age (18-20 years), delivery outcome (stillbirth/unknown), PPD during the postpartum period, and history of any mental disorder diagnosis.

In summary, the findings of this report suggest that a history of mental disorders was common among service women and dependent spouses with PPD, and, in turn, PPD was a strong predictor for suicidality in the postpartum period. These associations were most commonly found in younger age groups, but other predictors for suicidality included black, non-Hispanic race/ethnicity, Coast Guard service, and stillbirth/unknown delivery outcome.

The findings of this report emphasize the importance of PPD screening during the postpartum period. Mothers typically have only one postpartum visit, approximately six weeks after delivery, and may not be seen again until their annual well woman check-ups. Additional screening assessments of mothers, around the same time as their infant well-baby visits, may be indicated. Since service women were diagnosed at a later time with PPD than dependent spouses, this may also suggest directing screening efforts for PPD to start immediately after delivery.