Postpartum psychosis: Does stress play a role in relapse?
Postpartum (or puerperal) psychosis is a rare — occurring in just 1–2 women per 1000 deliveries in the general population — but extremely severe postnatal mental illness. So severe, in fact, it is considered a psychiatric emergency requiring specialist care and/or hospitalisation. Indeed, if left untreated postpartum psychosis can have devastating consequences for a woman and her family, and in rare but tragic cases can lead to suicide and/or infanticide.
Beginning soon after childbirth, typically within days or weeks of the delivery, postpartum psychosis can develop without warning, escalate very quickly and soon become severe. Symptoms include elation, depression, or rapid fluctuations between elated and depressed mood. As the name suggests, women also experience psychotic symptoms in the form of delusions (unusual thoughts or beliefs), such as paranoia, and hallucinations (seeing, hearing, smelling or feeling things that are not there). Confusion is also a common symptom, and women may appear not to know who or where they are. Understandably, episodes of postpartum psychosis can be extremely frightening for the woman, her partner and her wider family.
While postpartum psychosis is among the most severe psychiatric disorders, with treatment and support, women will go on to make a full recovery. Nevertheless, understanding the causes of the illness could help prevent women from developing an episode of postpartum psychosis in the first place.
And this is where my work comes in. I am a postdoctoral researcher in the Stress, Psychiatry and Immunology Lab (the team who brings you the InSPIre the Mind blog), working in the field of perinatal mental health. I have a keen interest in advancing our understanding of risk and resilience factors for maternal perinatal mental illness, with the aim of developing targeted treatments and interventions for women most at risk. In this blog, I would like to tell you about the work we have been doing examining risk factors for postpartum relapse in women at increased risk of postpartum psychosis.
The exact causes of postpartum psychosis are currently unknown. Several factors have been proposed, including becoming a mother for the first time (primiparity), sleep disturbance, and the dramatic fluctuation in hormones that occurs during pregnancy and the early postnatal period. However, more research is required to better understand the factors underlying the illness.
One thing we do know is that women with a diagnosis of bipolar disorder or schizoaffective disorder and those who have experienced an episode of postpartum psychosis following a previous delivery are at much higher risk of experiencing an episode of the illness after giving birth. In fact, research has shown that up to 50% of women with bipolar disorder or schizoaffective disorder and those that have had a previous episode of postpartum psychosis will develop symptoms following the delivery.
But why do some women at risk become unwell after they give birth, while others stay well?
Last year we published an article in the scientific journal Psychoneuroendocrinology, which demonstrated that stress might be one of the key factors that make women already at increased risk of postpartum psychosis more susceptible to becoming unwell in the early postnatal period.
Specifically, our research found that postpartum women who had an episode of postpartum psychosis experienced more stressful life events and higher perceived stress, as well as showing biological changes. Indeed, we found higher levels of two main biological markers: cortisol, our main stress hormone, and high sensitivity C-reactive protein (hsCRP), an overall measure of inflammation throughout the body. But could these measures of stress already be present before the illness even begins? And, if so, could they help to predict in advance which women at high risk will go on to become unwell in the postnatal period?
It is this question that brings us to our current research and focus of this blog, describing a paper we published recently in Psychoneuroendocrinology. As part of the Psychiatry Research and Motherhood, or PRAM, Study, we recruited a group of women at increased risk of experiencing postpartum psychosis and followed them from the second trimester of pregnancy to 12-months post-delivery.
This study design enabled us to collect information on various types of stress, including experience of psychosocial stress (childhood trauma and stressful life events during pregnancy) and markers of the biological stress system (cortisol and inflammation), before the onset of any postpartum symptoms. In this particular study, we focused on postpartum symptoms, including depression, mania (feeling elated/high) or psychosis (having unusual thoughts or seeing/hearing things that are not there), that started within 4 weeks of the delivery.
So, what did we find?
The impact of childhood trauma
Firstly, we found that women at high risk of developing postpartum psychosis who had experienced severe childhood maltreatment, defined as experience of physical abuse, sexual abuse, antipathy (emotional abuse) and neglect prior to the age of 17 years, were almost five times more likely to have a psychiatric relapse in the first 4 weeks’ postpartum than women at risk who had not experienced maltreatment during childhood.
This finding suggests that asking women at increased risk of postpartum psychosis about their experiences of childhood maltreatment during pregnancy (perhaps as part of their routine antenatal care) could be important in helping to identify those women most at risk of having a psychiatric relapse in the early postpartum.
The impact of recent stressful life events
While early life stress, in the form of severe childhood maltreatment, predicted postpartum relapse, the same was not true for stressful life events in later life. Indeed, we did not find a link between experiencing a stressful life event (e.g., death of a close family member or friend, marital difficulties or major financial crisis) during pregnancy and relapse in the postnatal period.
We did, however, find that women at risk who relapsed were more likely to find the stressful life events distressing, in comparison to those who remained well. This suggests that it is not the experience of a stressful life event itself that increases the risk for postpartum relapse, but instead how distressing the individual perceives that life event to be. It is, therefore, possible that implementing interventions, such as problem-solving, self-calming or mindfulness techniques, which are aimed at lowering stress during pregnancy could help to reduce the risk of postpartum relapse in women at increased risk of postpartum psychosis.
Changes to the biological stress system
As I mentioned, we also looked at biological measures of stress during pregnancy. We were surprised to find, given our earlier findings that women with postpartum psychosis showed increased levels of hsCRP, that none of the inflammatory markers we investigated (including hsCRP) were increased during pregnancy in those who subsequently went on to have a psychiatric relapse in the postpartum period. This indicates that the measurement of inflammatory markers during pregnancy might not be able to provide an early indicator of which women at risk will become unwell after giving birth.
On the other hand, we did find that daily cortisol levels were elevated in the third trimester of pregnancy in the women at risk of postpartum psychosis who relapsed in the early postpartum, when compared with women at risk who remained well after giving birth. This is important, as it suggests that elevated cortisol in the third trimester of pregnancy might be a biological marker that we could use to help identify which of the women at risk of postpartum psychosis are most likely to relapse following the delivery. It also further highlights the potential need for interventions aimed at reducing maternal stress during pregnancy.
So, does stress play a role in postpartum relapse in women at risk of postpartum psychosis?
Our findings suggest that psychosocial and biological stress do play a role in determining whether women at high risk of postpartum psychosis experience a psychiatric relapse in the early postnatal period.
It is of course important to remember that we are still in the early stages of this work and much more research in similar prospective studies with larger samples of women at high risk of postpartum psychosis is needed before we can really answer this question.
It is also important to highlight that many factors are likely to be involved in determining whether or not women will experience a relapse in the early postpartum period and that experience of stress (whether in the form of childhood trauma or stress during pregnancy) will not result in a postpartum relapse for every woman at increased risk of postpartum psychosis. Indeed, many women at risk who experience these stressors will remain well after giving birth.
Nevertheless, my hope is that our research goes some way to improving our knowledge and understanding of the factors that might increase the risk of postpartum relapse in women most at risk of postpartum psychosis.
Understanding the risk factors for postpartum relapse will provide an opportunity to better monitor and support women at risk and ultimately develop targeted treatments and interventions aimed at preventing maternal postpartum mental illness.