Genetic and Environmental Factors Significantly Increase Risk of Postpartum Psychosis in Women with Affected Siblings

Recent research from Mount Sinai has uncovered a crucial link between familial history and the risk of postpartum psychosis, a rare but severe mental health condition that can occur in women after childbirth. The study revealed that women whose sisters have experienced postpartum psychosis are over ten times more likely to develop the disorder themselves compared to those whose sisters have not had it. This groundbreaking finding underscores the importance of genetic and shared environmental influences in the condition's development.

Published in the American Journal of Psychiatry and announced during the American Psychiatric Association's annual meeting, the study analyzed data from over 1.6 million women in Swedish national registries. Among 2,514 women who experienced postpartum psychosis within three months of their first delivery, those with sisters affected by the condition showed a markedly elevated risk.

Beyond the family connection, the research also identified that women with a sister diagnosed with bipolar disorder face double the risk of postpartum psychosis. The highest risk group consisted of women with a sister suffering from both bipolar disorder and postpartum psychosis, with their risk increasing fourteenfold.

It’s important to note that while the relative risk can be high within families, the absolute risk for women with an affected sister remains low at approximately 1.6%. This indicates that postpartum psychosis, although serious, is relatively rare, but familial history plays a significant role in susceptibility.

This study contributes to a growing understanding that postpartum psychosis and bipolar disorder, although related, are distinct conditions. Dr. Veerle Bergink from Mount Sinai emphasized the necessity of increasing awareness among women of childbearing age and healthcare providers regarding familial risk factors. Recognizing these risks early can lead to better prevention, support, and timely intervention.

Further research is underway to explore the genetic underpinnings of postpartum psychosis. Led by Dr. Behrang Mahjani, scientists are using advanced molecular techniques to identify specific genes involved. Understanding the genetic and biological mechanisms could pave the way for developing targeted treatments and preventative strategies, ultimately reducing the incidence of this life-threatening condition.

These findings highlight the importance of family history in postpartum mental health and stress the need for clinicians to incorporate familial risk assessment into postpartum care routines. Increased awareness and understanding can facilitate early diagnosis and intervention, improving outcomes for mothers at risk.

For more detailed information, see the study: Adrianna P. Kępińska et al, "Familial Risk of Postpartum Psychosis," American Journal of Psychiatry (2025).