Round 2: Does the Timing of Onset for Postpartum Depression (PPD) Matter?

In round 2 of this engaging debate, our leaders discuss the following question: Does the timing of onset for PPD matter from a biological perspective?

Transcript:

Nicole Cirino, MD: Hello, everyone, and welcome back to our Great Debate in Psychiatry, brought to you by the Psych Congress Network. We're now onto our second topic of this debate, where we'll discuss what the scientific literature has to say about the relevance of timing of onset of postpartum depression. I know Dr Barrett and I are both in agreement that neurobiological etiology cannot be overlooked here. Dr Barrett, can you get us started by reminding us what we know about the role of neuroactive steroids and other neurohormones that are implicated in the onset of PPD and other psychiatric illnesses in the perinatal period?

Melanie Barrett, MD: So, the pathogenesis of postpartum depression may include genetics, epigenetics, rapid changes in reproductive hormones, HPA axis dysfunction, and psychosocial stressors. So, if we look at things like estrogen and progesterone, those rise during pregnancy, peak in the third trimester, and then they drop precipitously with delivery. So, it's not thought to be the absolute levels of these reproductive hormones but rather a sensitivity that some women have to this rapid fluctuation that makes them vulnerable during this time to depression and anxiety, amongst other things. We can look at one of the progesterone metabolites, allopregnanolone, which is a neurosteroid. It also rises during pregnancy and drops quickly with delivery. It's thought to exert its action through the GABA system, right? So, we're thinking the GABA-glutamate balance and how that impacts the HPA axis. There's also interesting evidence looking at oxytocin, right? We know that it's something thought to regulate emotion, social interaction, and mother-baby connections. So, while the timing of the onset of postpartum depression may point to the underlying biological processes, it doesn't tease out the likely multifactorial nature of PPD, which can take place regardless of the specific time.

Nicole Cirino, MD: Thank you, Dr Barrett, for that excellent description of the neuroactive steroids. I think this is one of the most fascinating parts of our field, and it's a good time to be in this field as we're starting to learn more about these steroids. One thing that I noticed that upsets me in these discussions is when people say that postpartum depression is just like all other forms of major depressive disorder, and I think this is oversimplifying this complex condition, many of because of the reasons that you described, but we know that symptomatology, treatment, prognosis and other differences distinguished postpartum depression from major depressive disorder. Let's look at some of the differences here, and when you're reviewing the literature, we go back to literature from the early nineties with Dr Wisner and Hendrick and some of the real pioneers in our field. What we found that the symptoms are more common and more severe around women with the postpartum depression include anxiety, aggressive obsessional thoughts, thoughts that one is going to harm their infants, intrusive images, restlessness, agitation, and more significantly impaired concentration and decision-making. We're more likely to see these symptoms in postpartum depression as compared to major depressive disorders, likely because of the neuroactive steroids that you mentioned.

Furthermore, a large recent population-based registry study found that inpatient admissions and severe depression were significantly increased in the postpartum period as compared to pregnancy despite similar outpatient visits. What this has suggests that the postpartum onset of depression within 8 weeks postpartum, these women were more than four times more likely to present with severe depression compared to women who experienced depression during pregnancy. So, the condition that occurs in the first 8 weeks postpartum is more likely to result in hospitalization and have more severe symptoms. They also are more likely to present with anxious anhedonia subtype of depression compared with women who experienced depression during pregnancy as well. So, it does appear that there is a different set of symptoms and severity depending on if depression occurs during pregnancy vs the early postpartum period.

Melanie Barrett, MD: Yes, I agree, and I'd also like to point out that while many cases that we see a postpartum depression in major depressive disorder may appear identical clinically, there may be an underlying genetic difference. So, a study of twins and non-twin siblings indicated that PPD has a higher heritability than major depressive disorder. I think it's also worth mentioning here as well that barriers for treatment are different in the perinatal period, opposed to the general population. This includes a number of women and providers who discontinue or undertreat women during this period.

Nicole Cirino, MD: You're right, and that alters the course of the treatment and the percentage of women that have untreated conditions that possibly are also using psychosocial treatment strategies, right? So that's a lot of differences there. Alright, well, we're going to close up this segment. Thank you again, Dr Barrett, and thank you all for watching. This concludes round 2 of our debate. Next up is our final topic, where we'll discuss how the timing of onset affects our treatment decisions for postpartum depression and our respective practices.