“Baby Blues,” “After Birth Apathy,” “New Mother Melancholy.” Postpartum depression (PPD) is known by many names and affects between 10-20% of women in the year following birth (CDC, 2021). Sadly, many women are stigmatized for this condition because “They should be happy after welcoming a new child to the world.” I’m here to tell you that PPD is not only incredibly normal, but occurs due to very real and very significant changes that happen to a woman’s hormone levels and nervous system following childbirth! Today, let’s break down postpartum depression.
Like many things in the human body, PPD is not fully understood. There are several research-backed theories as to why it occurs, but more research is needed to better understand the intricacies behind the condition. I want to dive into 2 current models scientists cite when looking at the etiology, or cause of the condition:
Hormonal Withdrawal Model:
- This model posits that the depressed mood following pregnancy occurs due to the sudden drop in hormones
- Within days of childbirth, a woman’s estrogen and progesterone levels drop dramatically in order to return to their normal, pre-pregnant levels
- Estrogen and progesterone withdrawal studies have been conducted on rats have shown that the withdrawal of these hormones leads to depressive behaviors from the rats
Immune System Model:
- Immediately after pregnancy there are upticks in the body’s natural production of cortisol, a stress hormone that causes inflammation and is implicated in depression
- The HPA-axis is normally regulated by our circadian rhythms (internal day/night cycle), however it can become dysregulated after childbirth
- Some scientists believe that this dysfunction occurs due to changes in the mother’s immune system post pregnancy. Essentially, the mother’s immune system is severely suppressed during pregnancy to prevent the body from attacking the foreign tissue (fetus) growing within her body. These fluctuations may be enough to alter immune function and cause increased inflammation within the mother (which can contribute to depressive symptoms, as we discussed in a previous article
(Corwin & Pajer, 2008; Jolley et al., 2007; Li & Chou, 2016).
While our knowledge on PPD is still in its infancy, there is a lot of promising research being done to understand why it happens. The better we understand this, the better our treatments can be. That said, I encourage any readers who are struggling with PPD to seek help! It is an incredibly normal part of motherhood and there are a lot of efficacious ways to provide new mothers with relief. Know that you are not alone!