On World Maternal Mental Health Day, Lisa Jones, Professor of Psychological Medicine, discusses her research into postpartum psychosis.

It is not uncommon for new mothers to become mentally unwell.  Up to 20%, or 1 in 5, women will experience mental ill-health during pregnancy and in the year after childbirth (known as the postpartum period).  The most common postpartum mental illnesses are anxiety, depression, or a combination of both.  This is perhaps unsurprising given the number and scale of physical, psychological and social changes that accompany the arrival of a new baby.  What may be more surprising is that mental illness is the most common of all health problems affecting women during pregnancy and childbirth in the UK, and very sadly, that suicide is one of the leading causes of death of new mothers in the UK.

 

A pregnant woman holding her stomach

Some women will experience a particularly severe form of postpartum mental illness called postpartum psychosis, which typically starts suddenly and very soon after childbirth, usually within the first few days or weeks.  This is much rarer than postpartum depression, affecting around 1-2 of every 1000 new mothers (0.1-0.2%).  The symptoms of postpartum psychosis are varied and changeable but usually include delusions (believing things that are not true), hallucinations (seeing or hearing things that are not there), extremely high or irritable mood, feeling perplexed and confused, and unusual out-of-character behaviour such as being excessively talkative and over-familiar with other people. 

Postpartum psychosis is a medical emergency, which, in most cases, requires admission to hospital for specialist care and treatment.  It can be frightening, shocking and distressing for the whole family when a member experiences mental illness, and this is elevated during the period after childbirth when expectations on new mothers are often high.  EastEnders viewers may remember that Stacey Slater experienced postpartum psychosis after the birth of her baby, Arthur, a few years ago.  The producers ensured a sensitive and accurate portrayal of postpartum psychosis by seeking input from experts, especially from women who have experienced the illness.

Investigating the Causes

A pregnant lady is holding her bump with both hands and sitting in a field.

For many years my research group has been investigating the causes and triggers of a serious mood disorder called bipolar disorder.  We have recruited the largest sample of people who have bipolar disorder in the world.  Over 7000 individuals from all over the UK have participated in our studies to date, and continue to help us with our research.  We have shown that women who have bipolar disorder are at much higher risk of postpartum psychosis than women in the general population.  One in five women with bipolar disorder who had given birth in our sample experienced postpartum psychosis, or 20% which is one hundred times higher than the 0.2% women in the general population.  We have also shown that women who have bipolar disorder are especially at risk of postpartum psychosis after having their first baby, if they have previously had postpartum psychosis and if they have a close biological relative who has had postpartum psychosis.  

Importantly, some of the known risk factors for postpartum depression, such as women having a personal history of childhood trauma, were not associated with increased risk for postpartum psychosis in our sample, showing that the causes of postpartum depression and postpartum psychosis are not the same.

Our Current Research

While we have made some progress with understanding the causes of postpartum psychosis there is much still to learn about this complex illness which is under-researched.  For example, many women with bipolar disorder who are trying to become pregnant or are pregnant choose to stop taking their bipolar disorder medication because they are concerned about possible harms to their foetus.  It is possible that coming off medication might contribute to the high rate of postpartum psychosis in women who have bipolar disorder.  In order to address this question and others, we are currently undertaking the largest and one of the first ever follow-up studies of pregnant women who have bipolar disorder.  Over 130 women have so far joined our study, and allowed us to interview them during early pregnancy, again just before they give birth and at 3 months after their baby is born. 

We are indebted to the women who are helping us with our research by allowing us access to their lives at what is already a complicated and challenging time for many of them and their families. 

Our results are still at a very early stage, and we need many more women to join the study because every woman’s experience is unique, but our emerging findings suggest that having an episode of mental ill-health during pregnancy and having a particular type of bipolar disorder, called bipolar I disorder, may increase the risk of having postpartum psychosis.  Our data also suggest that having postpartum psychosis is not associated with lack of emotional support from the woman’s partner and family.

A baby wearing a woolly hat is yawning

The reason we are working to understand more about the causes of postpartum psychosis is so that women, their families and clinical teams can have accurate information based on high-quality research.  Our findings will inform the difficult decisions that women who have bipolar disorder have to make about whether or not to start, continue with, or change medication during pregnancy for example, and will help women who are at particularly high risk of postpartum psychosis to be identified early and given the extra support and care they may need to ensure the best possible outcomes for them and their babies. 

Women and their partners can often feel guilty and blame themselves when postpartum mental illness happens, but our research shows this is misplaced.  Postpartum psychosis is not caused by something the woman and her partner have or have not done or thought.  The primary factors involved in whether or not a new mother experiences postpartum psychosis are biological, including genetic make-up.  We therefore hope that our research can also help to reduce feelings of guilt and shame and encourage new mothers who are concerned about their mental health to talk to a health professional without delay.

I would like to thank all our research participants without whose help and support our research could not happen, and my colleagues, Dr Katherine Gordon-Smith and Amy Perry, who work closely with me on all aspects of our postpartum psychosis research.  You can find out more about our research here.

 

Professor Lisa Jones and members of her research group teach and supervise research projects about mental illness on many courses at the University of Worcester, including Psychology BSc (Hons), Midwifery BSc (Hons), Nursing BSc (Hons), Physician Associate MSc, and Paramedic Science (BSc Hons).