Women With Diabetes Before Or During Pregnancy At Significantly Increased Risk Of Postpartum Depression

In the first study of its kind, investigators at Harvard Medical School and the University of Minnesota School of Public Health report that low-income women with diabetes have a more than 50% increased risk of experiencing this serious illness.

"While previous studies have linked diabetes and depression in the general population, this is the first time, to our knowledge, that the relationship has been studied specifically in pregnant women and new mothers," says Katy Backes Kozhimannil, research fellow in the Department of Ambulatory Care and Prevention at Harvard Medical School and Harvard Pilgrim Health Care. "We believe these findings may help clinicians better identify and treat depression in new mothers."

For over 25 years, clinicians have been aware that new mothers are at risk for postpartum depression. However, the condition is difficult to identify. Many symptoms are attributed to the every-day struggles of being a new mother. Others, such as irrational thoughts about harming the baby or, conversely, obsessing over the baby's health, are simply difficult for new mothers to admit.

To investigate the potential link between diabetes and postpartum depression, Kozhimannil and Bernard Harlow, professor in the University of Minnesota's School of Public Health, examined medical claims data from the New Jersey Medicaid program, looking at information from 11,024 new mothers who had given birth between July 2004 and September 2006. All women in the study were eligible for Medicaid 6 months prior to and one year after delivery and had incomes less than 115% of the federal poverty line ($24,000 for a family of four in 2006).

The researchers identified a woman as having depression if her records indicated a diagnosis, or if she had filled a prescription for an antidepressant medication during the study period. (Diabetes was also identified using both diagnosis and prescription information.)

Study data indicated that 9.6 percent of women with diabetes, who had no indication of depression during pregnancy, developed depression during the year following delivery, compared with 5.9 percent of women without diabetes. Put another way, pregnant women and new mothers with diabetes were approximately 55 to 60 percent more likely to experience postpartum depression. The increased risk of postpartam depression is similar for women who already had diabetes and those who developed it during pregnancy.

The researchers caution that these findings do not establish that diabetes causes postpartum depression, only that the two are related. Also, the medical claims data they used did not contain information on personal or family history of depression, weight or body mass index. Plus, it isn't yet clear the extent to which one can generalize findings from such a specific and localized population.

Still, according to Kozhimannil, "Health care facilities and clinicians that serve low-income and Medicaid populations may want to pay particular attention to managing the mental health concerns of women with diabetes during pregnancy and the postpartum period."

This research was funded by the Department of Ambulatory Care and Prevention, Harvard Medical School; Harvard Pilgrim Health Care Foundation.