Breastfeeding and depression: It’s complicated

A recent Facebook post by Jack Newman has elicited passionate discussion about the relationship between breastfeeding and postpartum depression. Dr. Newman posted an email he’d received yesterday:

My baby is 3 months old and breastfeeding has been “bliss” for me so far. We both enjoy our relationship and it is very important for me as I have postpartum depression and right now breastfeeding is the only thing that works as I would have hoped and planned. (My comment: Many mothers tell me that they are told to stop breastfeeding for medication for postpartum depression and say that they are so upset because “breastfeeding is the only thing in their life that is working”. Do doctors ever think of this?).

I’m happy to report that I’m a doctor, and I do think of this — in fact, at UNC, we’re starting a 5-year NIH-funded study to try to understand the relationship between breastfeeding, postpartum depression, and infant attachment.  Our pilot data suggest that this relationship is complicated. We recruited 52 women who were intending to breastfeed and either did or did not have a history depression and/or anxiety. During pregnancy, mothers provided baseline blood samples, completed questionnaires, and had a standardized psychiatric interview to assess their history. Mothers came to our lab with their babies at 2 and 8 weeks postpartum, and we measured hormone levels while they breastfed their babies.

During pregnancy, we found that mothers who had higher levels of the hormone oxytocin had lower scores on the EPDS, a standard measure of depression, consistent with another recent study of oxytocin and mood symptoms.  When mothers returned at 2 weeks, we did not find any relationship between mood and hormone levels during breastfeeding, but at 8 weeks, the mothers with higher depression and/or anxiety had lower levels of oxytocin during breastfeeding (see figure). They were also less happy, and more stressed, depressed, irritated and overwhelmed, during the entire feeding visit than mothers who were not anxious or depressed.

Maternal neuroendocrine response to feeding 8 weeks among women with depression/anxiety symptoms (dashed line) or without mood symptoms (solid line).

These results raise some interesting questions about the conventional wisdom that breastfeeding prevents depression. It could be that mothers who have lower oxytocin levels have trouble with breastfeeding and also feel more anxious and depressed. Or it could be that, for mothers whose baseline oxytocin is lower, breastfeeding gives them a boost that’s essential for them to feel connected to their babies.

There is also provocative evidence that oxytocin may increase stress in some individuals. A study of men who were or were not separated from a parent in childhood found that a dose of inhaled oxytocin actually increased levels of the stress hormone cortisol among the men who had experienced early parental separation.  In a small study in Australia, depressed mothers were treated with inhaled oxytocin at one lab visit and placebo at another visit. When mothers received oxytocin, they were more likely to describe their infants as difficult, and were sadder, but also reported a more positive relationship with their infant. The study included mothers of infants who were 3-12 months old, and 40% of the women in the study were breastfeeding at the time of the visit. It’s not clear whether the effect of oxytocin would be different in a group of mothers who were all breastfeeding. However, these results suggest that the oxytocin increase triggered by breastfeeding may worsen anxiety and depression for some mothers. In our five-year study, we will explore these issues in a larger sample — we plan to recruit 234 women and follow them and their infants through 12 months postpartum.

The nuances of the biology suggest that doctors absolutely need to think about the effect of breastfeeding on a woman’s mood symptoms — and that the effect likely differs from mother to mother. I have cared for women with postpartum depression who describe breastfeeding as the only thing that ties them to their baby. I’ve also cared for women who are struggling with milk production and spending all of their time trying to eek out a few more drops of breast milk, at the expense of their baby’s other needs. One mother, who came to see me during her second pregnancy to talk about strategies to optimize breastfeeding, recalled one day when her first baby was 4 months old. He was lying on the floor, screaming, and she was ignoring his cries because she was busy pumping. She said she realized, at that moment, that she needed to prioritize mothering over making milk.

We have much more work to do to understand the biology of postpartum depression. However, when a mother is experiencing depression and anxiety symptoms, my job as a clinician is to ask her what parts of her day bring her joy and peace, and what makes her symptoms worse. I need to ask her how breastfeeding is going — and listen, without judgment, to her answer. If breastfeeding is the lifeline that is holding her and her baby together, then we’ll build her treatment around protecting that breastfeeding relationship. Conversely, if she grits her teeth for every feeding and counts the minutes until it is over, then breastfeeding may be contributing to her symptoms and hurting her relationship with her baby.  We need to talk about why breastfeeding is stressful, and whether there are strategies that can make the experience better — or whether she and her baby would be better served if she weaned.  On a population level, not breastfeeding is associated with risks of both maternal and infant disease. On an individual level, however, a doubling in the risk of an ear infection may be a reasonable tradeoff for a doubling of mom’s dislike of her baby, eight to ten times every day.

So in answer to Dr. Newman’s post — yes, doctors do “ever think about this.” More importantly, we need to take the time to talk about it with each mother that we see. We need to explore what breastfeeding means for her, and we need to tailor our recommendations to her needs in order to reduce her depression symptoms and strengthen her relationship with her baby.

Alison Stuebe, MD, MSc, is a maternal-fetal medicine physician, breastfeeding researcher, and assistant professor of Obstetrics and Gynecology at the University of North Carolina School of Medicine. She is a member of the board of the Academy of Breastfeeding Medicine.

Posts on this blog reflect the opinions of individual ABM members, not the organization as a whole.