Oxytocin does not improve social functioning in children with autism, study finds

Daily intranasal therapy with the hormone oxytocin did not appear to improve social functioning among children with autism spectrum disorder, according to an NIH-funded study, contradicting smaller studies supporting its off-label use.

The new finding, published in The New England Journal of Medicine, is from a 24-week, placebo-controlled phase 2 trial of intranasal oxytocin that enrolled 290 children aged 3 to 17 years and randomly assigned them in a 1:1 ratio to receive oxytocin or placebo intranasally up to twice daily.

Just more than 48% of trial participants included in the efficacy analysis had minimal verbal fluency, and 52% had fluent verbal speech. Most participants were male, at 87%.

All participants were vetted for a score on the Aberrant Behavior Checklist modified Social Withdrawal subscale (ABC-mSW), which includes 13 items and a score that ranges from 0 to 39, with higher scores indicating less social interaction. The researchers said secondary outcomes included two additional measures of social function and an abbreviated measure of IQ. They recorded these scores before and after the trial period and used the least-squares mean change from the initial baseline as their final outcome.

They found that the therapy showed no significant difference between the treatment and control groups on measures of cognitive functioning, as measured over the course of 24 weeks from August 2014 through June 2017.

“Across the 24 weeks of the trial, the least-squares mean change from baseline in the ABC-mSW score (primary outcome) was 3.7 in the oxytocin group and 3.5 in the placebo group (difference, 0.2 points; 95% CI, 1.5 to 1.0; P = 0.61),” they wrote.

The results showed that, rather than as previously reported, oxytocin showed no noticeable improvement in social understanding within the patients.

In a related editorial, Daniel H. Geschwind, MD, PhD, director of the Institute for Precision Health at the University of California, Los Angeles, asked: “What can we conclude from this well-powered, carefully conducted trial?”

“First, we see that oxytocin as administered in previous clinical studies and trials and in a method similar to most off-label use in clinical practice did not improve social function in a generalizable population of persons with autism spectrum disorder,” he wrote. “These results do not support the current off-label use of oxytocin in the treatment of autism spectrum disorder.”

He said the issue would take further research to resolve.

“Looking ahead, as we enter the era of precision medicine in which treatment may be based on genetically informed disease mechanisms, the hope is that we can leverage genetic and molecular biomarkers in trial design and patient selection to improve outcomes in autism spectrum disorder and other neurodevelopmental disorders,” he concluded.

References:

Geschwind D, et al. N Engl J Med. 2021;doi 10.1056/NEJMe2110158.

Oxytocin does not improve social functioning in children with autism spectrum disorder, NIH-funded study suggests. https://www.nih.gov/news-events/news-releases/oxytocin-does-not-improve-social-functioning-children-autism-spectrum-disorder-nih-funded-study-suggests. Published Oct. 13, 2021. Accessed Oct. 14, 2021.