When does postpartum depression begin? The worst begins prenatally

Depression that begins before or during pregnancy is typically worse than depression that begins postpartum because it’s more severe, lasts longer, and usually goes undetected until the clinician screens for it after the baby is born, according to a study published online May 28, 2016 in the Journal of Affective Disorders.

“There’s a difference between postpartum depression and depression that started before or during the pregnancy. It’s not a homogenous disorder,” said the study’s corresponding author Sheehan Fisher, PhD, an instructor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine, in Chicago, IL.

Postpartum depression is prevalent, occurring in approximately 13% of mothers.

“When clinicians see a mother during the postpartum period and diagnose her with depression, it’s important for them to ask how long this depression has been an issue so they can assess the longevity and severity,” Dr. Fisher explained.

In fact, the time period when depression begins can indicate its severity and course, the researchers found. Depression prior to pregnancy implies a more chronic form that isn’t related to hormonal change or postpartum stressors.

This study is one of the first to investigate the time of onset of depression in mothers. The researchers assessed symptoms of depression in 727 mothers at an urban hospital at 4 to 6 weeks after the mothers gave birth. The researchers found that depression began postpartum in only 38.4% of mothers, while 36.7% developed depression during pregnancy, and 24.9% had it before pregnancy.

The investigators also sought to identify factors and symptoms that would characterize the periods of depression onset. Their results showed that mothers who developed depression during the postpartum period were more likely to be white, older, educated, married/cohabitating, and have private health insurance when compared with mothers whose depression began before or during pregnancy.

“Mothers who develop postpartum depression often [have] protective risk factors such as better access to resources, fewer children, and are more mature, which helps them adapt to the stress of pregnancy,” Dr. Fisher said. “Once their babies are born, they show more obsessive-compulsive symptoms—like over-worrying about their baby’s health—than mothers who developed depression before or during pregnancy.”

Women who had depression before they became pregnant were more likely to experience hypersomnia and have more symptoms of paranoia, such as a psychotic episode, than women who developed depression during or after pregnancy. These mothers also had a higher severity of postpartum depression than those whose depression began in other periods.

Mothers with bipolar depression (which is more severe than unipolar depression) were more likely to have a pre-pregnancy onset (38.7%), compared with those who had prenatal (22.6%) or postpartum onset (17.9%), Dr. Fisher noted. 

This investigation is novel because it studied an obstetric population rather than a psychiatric population, “which provides generalizable information to the larger population of childbearing women,” the authors noted.

A clinician who suspects postpartum depression in a patient should perform a comprehensive assessment of onset timing, typical and atypical symptoms, and unipolar versus bipolar disorder to improve the effectiveness of postpartum treatment, the researchers recommended.