From 2000 to 2015, the rate of depression diagnoses among women hospitalized for the delivery of a child rose seven-fold, from 4.1 cases per 1,000 patients to 28.7 per 1,000, the study found.
The study wasn’t designed to determine what caused the spike in diagnoses. It “could be the result of a true increase in cases of depression over the time period, better recognition of depression, or improved diagnoses after screening and assessment,” said lead study author Sarah Haight, a researcher with the U.S. Centers for Disease Control and Prevention in Atlanta.
“Generally speaking, it’s important for patients to know that depression – including perinatal and postpartum depression – is common and treatable,” Haight said by email. “It’s also important to know that it doesn’t feel the same for everyone.”
During pregnancy and the postpartum period, depression affects about eight percent to 13 percent of mothers, Haight and colleagues note in Obstetrics & Gynecology.
Depression during pregnancy is tied to an increased risk of poor nutrition, alcohol and drug use, obstetric complications and preterm births. It can also affect children’s mental and emotional health and motor development, the study team writes.
By the end of the study, depression diagnosis rates were lowest in Hawaii and Nevada, at less than 14 cases for every 1,000 patients. Rates were highest in Vermont, Minnesota, Oregon, and Wisconsin, at more than 31 cases for every 1,000 patients.
In 2015, depression diagnosis rates were highest among mothers 35 and older, women with health coverage through public insurance programs like Medicaid, and white mothers.
This could reflect differences among mothers from different backgrounds as well as bias among providers, said Erika Forbes, a researcher at the University of Pittsburgh, in Pennsylvania, who wasn’t involved in the study.
“Women from different ethnic, socioeconomic, or generational backgrounds might describe or experience depressive symptoms differently, and anyone assessing depression should have awareness of that,” Forbes said by email. “Furthermore, medical professionals assessing the women in this study might have been more inclined to think that white, non-Latinx women or women over 35 are suffering from depression, thereby missing it in women with different characteristics.”
The study may have underestimated the number of women with depression right after delivery, researchers acknowledge. This is due in part to the lack of data from some U.S. states, the lack of universal depression screening for new mothers and the study’s reliance on hospital billing records to identify depression cases.
Even so, the results mirror a rise in depression diagnoses in the general population, said Myrna Weissman, a researcher at Columbia University in New York City who wasn’t involved in the study.
“Women are twice as vulnerable to depression as men, and childbirth with rapid changes in hormones and rapid psychosocial life changes increase vulnerability to depression,” Weissman said by email.
Mild mood swings are normal during pregnancy and soon after delivery, but mood changes that persist more than a day or two or interfere with daily activities and relationships are not normal, Weissman said. Ideally, all women should be screened for depression during pregnancy, and women who are depressed or at high risk should get treatment.
“Postpartum blues refers to a relatively short period of mild levels of increased sadness, anxiety, and related symptoms that follow delivery . . . and typically go away within a week,” said David Bridgett of Northern Illinois University in DeKalb.