• Posted May 23, 2025

Family Link For Postpartum Psychosis Discovered

FRIDAY, May 23, 2025 (HealthDay News) — Women are 10 times more likely to develop postpartum psychosis if they have a sister who experienced the condition after an earlier pregnancy, a new study says.

Postpartum psychosis is a rare but serious mental illness that causes severe mood swings, hallucinations, delusions, paranoia and thoughts of self-harm among new mothers.

If left untreated, the condition increases risk of suicide or infanticide, researchers said in background notes.

These new results indicate there might be shared genetic and environmental influences that increase risk of postpartum psychosis, researchers said.

“Every woman of childbearing age and their physicians need to know about the existence of, severity, symptoms and familial risk for postpartum psychosis so it can be promptly diagnosed and, hopefully, prevented,” said co-senior researcher Dr. Veerle Bergink, director of the Women’s Mental Health Center at Mount Sinai in New York City.

“At present, too many women at higher risk don’t know it and are left on their own with a new baby and no support,” she added in a news release.

For the study, researchers analyzed the records of more than 1.6 million Swedish women, identifying more than 2,500 who experienced postpartum psychosis within three months of their first childbirth.

Results showed that a woman had 10 times the relative risk for postpartum psychosis if their sister had suffered it.

Women also had double the risk if her sister had bipolar disorder, researchers found.

The odds were highest in women whose sister had both postpartum psychosis and bipolar disorder — 14 times increased.

However, the absolute risk of postpartum psychosis is still low, even in these women, researchers noted. New moms with an affected sister have an overall 1.6% risk of postpartum psychosis.

“These findings support the view that even though there is overlap between postpartum psychosis and bipolar disorder, these are in fact, distinct conditions,” Bergink said.

“We hope this new data will help move the needle and impart change,” she added. “With wider recognition of this particular condition and risk factors for it, measures can and should be taken to help ease the burden for women during this postpartum period.”

Researchers at Mount Sinai have already begun to explore the genetics behind postpartum psychosis.

“We’re using complex molecular data to investigate the genetic architecture of the disease,” researcher Behrang Mahjani, an assistant professor of psychiatry at the Icahn School of Medicine at Mount Sinai, said in a news release.

“Knowing what specific genes are involved will help us dive into the mechanisms and triggers of postpartum psychosis, and if they’re hormone- or immune-related,” Mahjani continued. “And that, in turn, could lead us to novel treatments and ways to proactively inform women of their risk before they’re faced with a severe health crisis.”

The new study appears in the American Journal of Psychiatry.

More information

The Cleveland Clinic has more on postpartum psychosis.

SOURCE: Mount Sinai, news release, May 15, 2025