Does breastfeeding prevent postpartum depression?

It would be great if the answer were an unequivocal “Yes!” Postpartum depression, or PPD, is one of the most common complication of childbirth, affecting about 1 in 10 new moms, with devastating consequences.

A number of researchers have reported less depression among moms who are breastfeeding, compared with moms who are bottle-feeding. These findings have even led one team of scientists to put forward a theory that bottle-feeding mothers experience grief from not breastfeeding that’s similar to mothers who have had a stillbirth.

It’s a compelling theory, but it rests on tenuous evidence. The problem is that the overwhelming majority of studies looking at breastfeeding and depression are cross-sectional. This means that the researchers collected information on infant feeding and maternal mood at the same time.  In this type of study, it’s impossible to tell whether depressed moms wean earlier, or moms who wean earlier develop depression.

Researcher Cindy Lee Dennis reviewed 49 studies on breastfeeding and depression in a paper in the journal Pediatrics last year. She concluded that depressive symptoms are a risk factor for breastfeeding failure:

The results from this review suggest that women with depressive symptomatology in the early postpartum period may be at increased risk for negative infant feeding outcomes including decreased breastfeeding duration, increased breastfeeding difficulties, and decreased levels of breastfeeding self-efficacy.

Similarly, the AHRQ report on breastfeeding and maternal and infant health outcomes concludes:

It is plausible that postpartum depression led to early cessation of breastfeeding, as opposed to breastfeeding altering the risk of depression. Both effects might occur concurrently.

Of note, there is ample data that social support, maternity practices, and other factors impact breastfeeding outcomes, and it’s entirely possible that poor support leads both to depression and to early weaning.  The studies published so far haven’t teased out the role of these factors in the link between breastfeeding and postpartum depression. But for now,  there’s insufficient evidence to determine whether weaning causes depression, or depression causes weaning.

While researchers sort this out, it’s worth considering the potential harm of promoting breastfeeding as cure-all for postpartum depression. Postpartum depression is under-diagnosed and undertreated, and mothers often suffer in silence, not realizing that their symptoms are not normal and could be relieved with therapy or medication.

If mothers with postpartum depression get the impression that they aren’t at risk because they are breastfeeding, I worry that they may further delay seeking help. Similarly, if those of us in the breastfeeding community internalize the idea that breastfeeding prevents PPD, we may be less likely to recognize and treat breastfeeding mothers who are depressed.

The Edinburgh Postpartum Depression Scale (EPDS), a 10-question screening tool, is available in English and Spanish, and is a great tool for identifying moms at risk. The ABM reviews the EPDS in its detailed, evidence-based protocol on screening and treatment for PPD in nursing mothers.

So what’s the bottom line? There’s considerable data showing that moms who are successfully breastfeeding are less likely to be depressed than those who are not. It’s far from clear, however, whether depression causes weaning or weaning causes depression.

While the researchers try to sort out the answers, it’s safest to assume that all moms are at risk for postpartum depression. All  providers who care for mothers and babies must do our part to make sure that families do not suffer in silence with this devastating condition.

Alison Stuebe, MD, MSc, is a maternal-fetal medicine physician and assistant professor of Obstetrics and Gynecology at the University of North Carolina School of Medicine.