Hormone Widely Used as an Autism Treatment Shows No Benefit

Multicenter study finds that oxytocin is safe, but ineffective at boosting social skills among autistic children

Oxytocin, a naturally occurring hormone that acts as a chemical messenger in the brain, showed no evidence of helping autistic children to gain social skills, according to a large National Institutes of Health (NIH)-funded study led by Duke Center for Autism and Brain Development psychiatrist Linmarie Sikich, M.D., an associate consulting professor for Duke University School of Medicine. While disappointing for those holding hope that oxytocin could be beneficial, the long-awaited finding, which appeared in the New England Journal of Medicine, provides clarity for a treatment that has shown mixed outcomes in smaller, less robust studies.

“There was a great deal of hope that oxytocin would be effective,” said Sikich. “All of us on the study team were hugely disappointed, but oxytocin does not appear to improve social abilities in autistic people.”

Oxytocin is typically used to induce labor, but because of its activity in the brain, it has been investigated as a treatment for autism. Evidence has been conflicting, with several smaller studies suggesting it improved social and cognitive function among some children on the autism spectrum, while other studies showed no benefit.

With funding from the NIH, the research team designed the multi-site trial to provide the best evidence yet about whether oxytocin was a safe and effective treatment for autistic children. The study aimed to see if the regimen of oxytocin would have a measurable impact on the children’s social abilities based on screenings and assessments at the start of the trial, midway through the study, and at the end. While the oxytocin was well tolerated and had few side effects, it showed no significant benefit among the group of children who received it compared to those who received the placebo.

“This work underscores our commitment to rigorous research to support families making critical decisions,” explained Sikich. “Thousands of autistic children have been prescribed intranasal oxytocin before it was adequately tested. Now, we have data showing it is safe. Parents and caregivers deserve strong evidence about the safety and benefit of new treatments before they are offered as solutions.” She explained that no further study is likely of oxytocin, given the negative findings.

“Our consensus as investigators is that there is no evidence in this large study that is strong enough to justify more investigation of oxytocin as a general treatment for autism,” said Sikich. “We will continue to examine additional data gathered in the study to see if there are biologic markers or concurrent therapies that are associated specifically with response to oxytocin and not with response to placebo.”

Sikich L, Kolevzon A, King BH, McDougle CJ, Sanders KB, Kim SJ, Spanos M, Chandrasekhar T, Trelles MDP, Rockhill CM, Palumbo ML, Witters Cundiff A, et al. Intranasal oxytocin in children and adolescents with autism spectrum disorder. N Engl J Med. 2021 Oct 14;385(16):1462-1473.