Oxytocin

The SOARS-B trial was a multisite, phase II, double-blind, placebo-controlled RCT enrolling 290 children and adolescents (ages 3-17) with ASD, randomized to 24 weeks of intranasal oxytocin or placebo. On the primary endpoint, the least-squares mean change in the Aberrant Behavior Checklist modified Social Withdrawal subscale (ABC-mSW), there was no significant between-group difference (least-squares mean change 3.7 with oxytocin vs 3.5 with placebo). No significant benefit was observed across secondary measures of social or cognitive functioning, and adverse events did not differ substantially between groups. As the best-powered oxytocin trial in autism to date, it provides strong evidence against efficacy of intranasal oxytocin for core social deficits in pediatric ASD.

This was the largest and most rigorous test of whether a daily oxytocin nasal spray helps children and teens with autism become more socially engaged. Over six months, kids who got oxytocin did no better than those who got a placebo (an inactive spray) on measures of social withdrawal and social skills. The spray was generally safe but simply did not improve the core social difficulties of autism. The results were an important, disappointing check on earlier hopes that oxytocin could be an autism treatment.

In this landmark double-blind, placebo-controlled experiment, healthy male participants received intranasal oxytocin or placebo before playing a monetary trust game in the role of investor. Oxytocin significantly increased investors' transfers to trustees, with a substantially higher proportion showing maximal trust compared with placebo. A control risk experiment, in which payoffs depended on a random mechanism rather than a human partner, showed no oxytocin effect, indicating the hormone specifically increased willingness to accept social (interpersonal) rather than general risk. This provided early causal human evidence linking oxytocin to prosocial, trust-related behavior.

Researchers gave healthy men either an oxytocin nasal spray or a dummy spray, then had them play a money game that measures how much they trust a stranger to reciprocate. People who got oxytocin were more willing to hand over their money, trusting their partner more. Importantly, oxytocin did not make people take more risks in general (like gambling on chance), only more willing to trust another person. This influential study helped launch oxytocin's reputation as a 'trust' or social-bonding hormone, though later work shows the effects are less robust than first believed.

This meta-analysis pooled 17 randomized controlled trials (466 participants) testing intranasal oxytocin on social-cognitive outcomes in neurodevelopmental disorders such as autism spectrum disorder. Across studies, oxytocin had no significant effect on emotion recognition (Hedges' g=0.08) and a moderate but non-significant effect on empathy (g=0.49), with only a small significant effect on theory of mind (g=0.21). Effects were not moderated by diagnosis, age, dose, or administration frequency. The authors concluded the therapeutic promise of intranasal oxytocin should be considered tentative, underscoring the mixed and inconsistent nature of the social-behavior literature.

This study combined the results of 17 well-controlled trials to see whether oxytocin nasal spray genuinely improves social understanding in people with conditions like autism. Overall, the evidence was weak and mixed: oxytocin did not reliably help people read emotions, and only showed a small effect on understanding others' mental states. The benefits also did not depend on age, dose, or diagnosis. The authors cautioned that the excitement around oxytocin as a social treatment is not yet backed by strong, consistent results.