Round 3: Is postpartum depression (PPD) similiar to major depressive disorder (MDD)?

In the final debate round, Dr Camille Hoffman and Dr Jennifer Payne support their sides of the argument by comparing PPD with MDD.

Dr Gisele Apter: Okay. Hi everyone, and welcome back to our Great Debates in Psychiatry series, brought to you by Psych Congress Network. In our third and final round of this debate, we'll discuss whether postpartum depression is similar to major depressive disorder. And again, we will start with Dr Payne, and then we will have Dr Hoffman discuss this point with Dr Payne. So, Dr Payne, your opening argument, please.

Dr Jennifer L Payne: Well, I think of the postpartum time period as an especially vulnerable time period for the development of a major depressive disorder. When I think about major depression, it's really a heterogeneous disorder, likely with several different underlying but overlapping pathophysiologies. And I actually decided to study postpartum depression because it's the only time when you can predict when someone will develop a major depressive episode. The postpartum time period is high risk, likely because of several risk factors, including stress, sleep deprivation, and changes in hormone levels such as estrogen, progesterone, and allopregnanolone. There's also evidence that a subset of women are prone to mood symptoms during times of normal reproductive hormone hormonal change. So women who are biologically vulnerable to hormonal changes are likely to develop major depression during the postpartum time period. I think it's likely that the underlying biology for postpartum depression vs major depression outside of the postpartum time period is similar or related, but probably not completely identical. That being said, women who develop postpartum depression, most of them go on to have depression outside of the postpartum time period. So, I think that they are not identical, but they are related disorders.

Dr Apter: Thank you very much. Dr Hoffman, your starting opening argument on this round 3.

Dr Camille Hoffman: Mechanism of action of allopregnanolone replacing hormonal fluctuations or deficiencies, really that naturally occur in the postpartum period, is an established mechanism. And it makes a lot of sense from a perinatal perspective how that hormonal fluctuation can interact with other risk factors that we've discussed to lead to a postpartum diagnosis or postpartum depression, sorry, episode. On the other hand, there are more critical periods, in my opinion, within which postpartum depression exists compared to a major depressive episode. I know that I have a very perinatal-centric view of the world, but we know that maternal mood has a lifelong influence on the long-term health and wellness of the child. There are decades of data establishing this, and so to me, that is part of why it is a more critical period for diagnosis and treatment. As Dr Payne mentioned earlier, a parental mental illness is a point on someone's adverse childhood experiences score, and we'd really like to prevent that.

Dr Hoffman: We know that we know how much childhood adversity impacts overall life course health. So, another consideration is that changes that occur to the infant later during the postpartum period, are changes that are occurring to the infant during the postpartum period are more rapid and dramatic in terms of neurodevelopment and behavioral development compared to a child once he or she's three or four. And I tell patients all the time, you know, three months between ages three and six months, or six and nine months, is way different than three years; three months to three years, six months, developmentally. And so we really have the opportunity to change the childhood trajectory by improving The early childhood experience for the mom, obviously, but also because of the rapid infant neurodevelopment that's happening. So, postpartum depression is really different to me from major depression in the impact that it has on two individuals. Sure, major depression has impact on multiple individuals beyond the patient who's receiving the treatment, but it's really different. And we have to acknowledge that if we're going to try and reduce both the risk of maternal morbidity and mortality related to this, which obviously affects the child, but also prevent one point on the ACE score for the child, knowing that there are long-term repercussions of this condition, especially during this time period.

Dr Apter: Thank you. Those are really great points. Dr Payne, what would you answer?

Dr Payne: So, I agree with Dr Hoffman that the postpartum depression has significant effects not only on the mother but the exposed children as well, and, therefore, it makes it even more critical that we identify postpartum depression and get it treated. I don't think that makes it a separate disorder from major depression. However, and from a biological perspective, we think that at least 1 part of the pathophysiology of postpartum depression are changes in allopregnanolone levels that occur at the time of delivery and changes in the GABAergic system. Allopregnanolone and the GABAergic system are involved in stress regulation in the brain broadly, and it's likely that both are involved in the development of major depression outside of the postpartum time period. The main thing about postpartum depression, it's clear that there are changes in allopregnanolone and postpartum that make them, postpartum time period, vulnerable to the development of depression.

Dr Payne: The changes in major depression are a little bit less clear and are harder to study simply because you can't predict the onset of a major depressive episode outside of the postpartum time period. Studying postpartum depression is one way that we can try to understand the underlying biology for major depression, in general, because we can predict when illness will begin, and we can start to measure things biologically prior to onset of postpartum depression. So, I think the two are quite related, but I agree that it's even more critical to identify and treat postpartum depression quickly and effectively.

Dr Apter: Thank you so much. Dr Hoffman?

Dr Hoffman: When I first learned of Dr Payne's research on this in, and this parallel that she just mentioned, it occurred to me, oh, we use pregnancy as a way to identify a risk or a predisposition to multiple conditions that are going to evolve over the life course. So, that completely makes sense to me. And I'm happy that the mechanism and physiology, it can be used in a way to identify someone's risk. We know pregnancy is a great unmask of a predisposition to many things: to hypertensive disease later in the live course of the woman, to diabetes in the case of gestational diabetes. And so obviously, in this case, two major depressive episodes later in the life of someone who has postpartum depression, I still hold that it's most important and most critical for the newborn and the child to address the mental health conditions. Sure, gestational diabetes exposure to a fetus also can make, can have some metabolic repercussions, but the overlap with mental health and gestational diabetes is also something that we know exists. So this is something that is easy to modify if you can recognize it early in the postpartum period, whereas these other conditions, like evolving hypertension or evolving metabolic disease, are much more slower and gradual to develop over the child's life course.

Dr Apter: Thank you, Dr Hoffman. So, in a way, before I asked you both for your closing statements, we're talking about the importance of the diagnosis and management of this disorder, both for the woman, the mother, and child. And obviously, women want their children to be well. So it's important for children, and it's even important for women, and then it'll be threefold important for both together if we want to put it that way. So, that's one thing. The other is obviously, what kind of illness are we talking about? And I thank you for both for mentioning and comparing this to, putting this in perspective with other illnesses that we know are occurring during pregnancy and the postpartum, such as you mentioned, diabetes and hypertensive. Illness. But, again, we are both comparing the question of mechanisms, which Dr Payne has been talking about, and the question of importance of diagnoses and treatment and then, obviously, what will happen in the future of this woman. So, Dr Payne, if you have a final closing statement on this third round of debate, please.

Dr Payne: Absolutely. So I, I think postpartum depression is a type of major depression that develops likely due to alterations in allopregnanolone and the GABAergic system, along with other risk factors that are specific to the postpartum time period. However, both allopregnanolone and the GABAergic system are more broadly involved in the central nervous system, and the regulation of stress and major depression can be thought of as an abnormal brain response to stress. And the postpartum time period can be thought of as a time that is particularly vulnerable for the development of major depression. Regardless, we need to identify and treat postpartum depression quickly and effectively for the sake of everyone involved.

Dr Apter: Thank you. Dr Hoffman, your opposing statement.

Dr Hoffman: So, I strongly believe that maternal child health is really the cornerstone of societal health, and disruptions during this time period can have lifelong consequences. We know that could also have lifelong benefits or buffers, depending on the health and wellness of the mother, the parents, the family. So, the perinatal period, as mentioned, is often considered a stress test that unmasks many conditions that manifest later in a woman's life. I've already talked about hypertensive disorders, gestational diabetes, and so in this scenario, PPD is the precursor to major depressive major depression.  So, we need to observe and treat a pregnancy, of course, to address the issues at hand during the pregnancy and early postpartum period. But we really need to broaden our lens with providing more guidance on learning long-term life course health and how this plays out for at least two individuals over an extended time period.

Dr Apter: Thank you both.  So we're here, coming to the end of our third round of discussion. We need you to tell us who you think won this round by answering the poll question you see on your screen and to be sure to tune in for our participants' final round of closing arguments.