Psilocybin may make postpartum depression worse, study finds

Psilocybin may heighten anxiety and depression in new mothers rather than help treat postpartum mental health conditions, research suggests.

Scientists found that giving mouse mothers the psychedelic drug – the active compound in magic mushrooms – increased anxiety and depressive-like behaviour linked to perinatal mood disorders, which are mental health conditions that can develop during or after pregnancy.

The results challenge assumptions about psilocybin’s therapeutic use, indicating it may not be suitable for all patient groups.

David E. Olson, director of the IPN and professor of chemistry, biochemistry and molecular medicine at UC Davis, said: “The IPN has done a lot of work demonstrating that a single dose of a psychedelic can lead to long-lasting, beneficial effects.

“But it’s a little more nuanced than that in terms of who can really benefit and who might be at risk.

“There are different patient populations.”

Researchers at the University of California, Davis Institute for Psychedelics and Neurotherapeutics tested the drug in a mouse model of postpartum depression.

In this model, mothers could escape into a separate cage, mimicking the infant avoidance seen in human postpartum depression.

The negative effects persisted for two weeks after a single dose.

More concerning, pups raised by psilocybin-treated mothers also showed anxiety and depression-like symptoms into adulthood, suggesting harmful effects were passed on through lactation and altered brain development.

Co-author Danielle Stolzenberg, associate professor of psychology at UC Davis, said: “One of the things that’s discussed consistently in the clinical literature is that mums often feel like they have trouble bonding with their infants when they’re experiencing depressive symptoms.

“The mouse mums in the social stress paradigm spend significantly more time in the cage without the pups.

“They will often run back and forth to check on them but tend to actively avoid their infants for long periods of time.”

The team had expected positive results given psilocybin’s reported benefits for other mental health conditions.

“Psilocybin was of such interest for us because it’s been demonstrated to be useful across a whole host of mental disorders, including addressing anxiety and depression,” said first author Cassandra Hatzipantelis, a postdoctoral fellow at the IPN.

“We thought it could have the ability to address things that go wrong in postpartum depression, like the parent-infant connection.”

Instead, the mouse mothers continued to avoid their offspring and showed persistent symptoms even after separation.

Psilocybin-treated mice were also at higher risk of behavioural impairments and depressive-like symptoms.

Nine weeks after weaning, both male and female offspring showed heightened anxiety and depression compared with control groups.

Their brains also contained traces of psilocin, the metabolite produced when the body processes psilocybin.

“We now know that even low doses of exposure can impact offspring for long periods of time,” Stolzenberg said.

“These could be really important therapeutics, but we also realise they have limitations, and we have to conduct rigorous science to understand what those limitations are,” Olson added.