As gynecologists we have postulated a lot of reasons for the fact that some women have post partum depression and others do not. Perhaps some women are more stressed and tired, or have had multiple other medical issues, less help at home, or conflicted reasons for becoming pregnant. Obstetricians have struggled with the reasons for post partum depression as much as they struggle to get this condition treated. So little is understood about post partum depression the current formal categories of psychiatric diagnosis do not recognize postpartum depression as being anything other than depression. We have thought that anemia, lack of sleep, thyroid disease, or resurgence of prior depression was the explanation for why some women get post partum depression. Now we may have finally found a physiological cause: the hormone oxytocin.
Oxytocin levels may now explain why some women do have the feelings of being depressed after having a baby, or one of the post partum spectrum diseases that includes baby blues, or full blown postpartum depression, or postpartum psychosis.The "baby blues" usually begins right after delivery, may be the worst in the first days at home with baby, and are often described as feeling a bit on edge, irritable or sad, and essentially go away without treatment. Postpartum depression is significant, you worry too much about the baby, have trouble concentrating and enjoying motherhood and may even get so difficult moms with this much depression think of killing themselves so they will not harm the baby. It is essentially clinical depression that will respond to the treatments we use for depression during pregnancy, and many of the medications are safe during breastfeeding as well. It is unfortunately very common, some studies say 1/5 women can experience postpartum depression. Actual postpartum psychosis is very rare and very serious. It can be difficult to diagnose. Poor sleep, mood swings and temporary improvement make it harder to diagnose. Thinking can become so disordered if not treated these patients may harm their infant, and a condition that still needs medical advances to prevent and treat.
Post partum depression is insidious. NYT article notes that these feeling actually begin during the preceeding pregnancy, not just post partum. Now that we are looking at oxytocin, it ties in to the fact that obstetricians have known oxytocin levels begin to rise through pregnancy. And the levels of oxytocin in healthy pregnancies may be higher than in women who have had poor outcomes in pregnancy such as miscarriage or stillbirth.
Oxytocin is a hormone that actually governs contractions in labor and milk production during breast feeding, but beyond it's role in delivery and lactation, social bonding, mother-child bonding and stress management, sexuality and overall health have been reportedly linked to the level of oxytocin..In March 2016 in Archives of Women’s Mental Health a group of researchers from Northwestern discovered that in their 66 women, the higher their oxytocin levels, the more depressive symptoms were experienced at six weeks. Symptoms they associated with post partum depression included waking up too early in the morning and not being able to get back to sleep, more worrying or anxiety, more aches and pains, headaches, changes in bowel patterns, feeling tired or a sense of heaviness, changes in appetite and feeling sad. Knowing a patient's oxytocin blood levels may some day help to screen for or perhaps even treat post partum depression. Currently obstetricians use easily administered questionnaires to track the mood changes post partum, but perhaps blood testing can be the test of the future; the Northwestern researchers feel very excited about their work pointing out that:
"Obstetricians routinely screen for non-psychiatric complications of childbearing such as gestational diabetes, using readily available biomarkers (blood tests)."
Other Northwestern authors include Dr. Katherine Wisner and Stephanie A. Schuette.
This work was funded by grant K23 DA037913 from the National Institute on Drug Abuse from the National Institutes of Health and other sources including Northwestern Memorial Foundation.