Published in The Lancet medical journal, the research, led by researchers in the Division of Psychological Medicine and Clinical Neurosciences at Cardiff University, has substantiated differences between postpartum psychosis and bipolar disorder for the first time.
For more than 150 years postpartum psychosis has been shrouded in controversy, hindering research.
It’s caused considerable confusion for clinicians and women, with potentially negative consequences.
We aimed to explore whether bipolar disorder and postpartum psychosis are as similar in symptoms, prognosis and risk factors as thought to be.
Similar conditions, but different
There are some differences as some women with first-onset postpartum psychosis are less likely to relapse.
We therefore wanted to compare the genetics for these disorders to better understand their differences and similarities.
We compared women with first-onset postpartum psychosis, where postpartum psychosis was their first psychiatric episode, and women with bipolar disorder, who had a recurrence during the postpartum and a group of control women.
The UK study involved 203 women with first onset postpartum psychosis, along with 1,225 women with bipolar disorder who had given birth, and 2,809 control women from the general population who did not experience the conditions.
We specifically looked at their genetic risk for schizophrenia, major depression and bipolar disorder.
When looking at their risk for schizophrenia and bipolar disorder, women with bipolar disorder and women with first-onset postpartum psychosis had similar levels and was higher than controls.
But if we looked at risk for major depression, women with first-onset postpartum psychosis had similar levels to controls, yet were lower than women with bipolar disorder.
Establishing differences for the first time
Our research suggests that postpartum psychosis may be partially genetically distinct from bipolar disorder with a postpartum recurrence, where these experiences had previously been considered to be comparable.
In the past, researchers have shown that there are clinical differences between the two, but this is the first time these differences have been substantiated.
It suggests that there are different but overlapping biological mechanisms at work in the two disorders.
Research leading to better treatment for women
This provides evidence to suggest that women with bipolar disorder who have a postpartum recurrence and women with first-onset postpartum psychosis may benefit from different treatment and management programmes.
We hope it will also help to raise awareness of postpartum psychosis and support its recognition as its own disease entity within the bipolar disorder spectrum.
In future research we’re hoping to expand on this study by collecting a larger sample of women with postpartum psychosis, collecting samples globally, as this sample was made up of people of European ancestry only.
We’re also hoping to develop assessment tools for postpartum psychosis which can be used in different countries and cultures, with the help of healthcare professionals and women with lived experience.
Read the full paper: Postpartum psychosis and its association with bipolar disorder in the UK: a case-control study using polygenic risk scores
Resources
- NCMH leaflet | Planning your pregnancy
- NCMH leaflet | Bipolar Disorder, pregnancy and childbirth