Intranasal oxytocin, social cognition and neurodevelopmental disorders: A meta-analysis. — VialBase Research

Summary

Deficits in social cognition are pervasive and characteristic of neurodevelopmental disorders (NDDs), and clinical trials of intranasal oxytocin (IN-OT) intended to remediate them have produced inconclusive results. This meta-analysis pooled randomized controlled trials to quantify the effect of IN-OT across specific social cognitive domains in NDD populations. Medline, PsychINFO, and Scopus were searched for RCTs published through 25 July 2017; seventeen studies met inclusion criteria, comprising 466 participants with a neurodevelopmental disorder. Using a random-effects model, the analysis found that intranasal oxytocin had no significant effect on emotion recognition (Hedges’ g = 0.08), a moderate but non-significant effect on empathy (Hedges’ g = 0.49), and a small but statistically significant effect on theory of mind (Hedges’ g = 0.21). Meta-regression tested whether the effect varied by clinically relevant factors and found that it was not moderated by participant diagnosis, participant age, or the dose or frequency of IN-OT administration — the absence of any dose-response relationship being a notable weakness in the case for a genuine pharmacological effect. The authors concluded that more well-designed RCTs are needed, that it remains difficult to draw conclusions about the potential for IN-OT to improve social cognition in NDDs, and that the promise of intranasal oxytocin should be considered tentative.

Key Findings

• Seventeen randomized controlled trials pooled, comprising 466 participants with neurodevelopmental disorders, from searches of Medline, PsychINFO, and Scopus through 25 July 2017
• Emotion recognition: no significant effect, Hedges’ g = 0.08 — a null result on the most commonly claimed social benefit
• Empathy: moderate but non-significant effect, Hedges’ g = 0.49 — the largest point estimate in the analysis, but it did not reach statistical significance
• Theory of mind: small but statistically significant effect, Hedges’ g = 0.21 — one significant result across three domains, at a small effect size
• Meta-regression found no moderation by diagnosis, age, dose, or frequency of administration — meaning higher or more frequent dosing was not associated with greater benefit
• Authors explicitly characterize the evidence as inconclusive and describe the promise of intranasal oxytocin as “tentative,” calling for more well-designed RCTs

Relevance to Oxytocin

This is the closest thing to a quantitative verdict on Oxytocin for the social and bonding effects that drive most consumer interest, and the honest reading is mixed-to-weak. Of three social cognitive domains, two showed no statistically significant benefit — including emotion recognition, where the effect size was essentially zero — and the one significant result, theory of mind, was small (g = 0.21). The empathy estimate is the sort of finding that gets quoted selectively: g = 0.49 sounds substantial, but it was not statistically significant, and reporting it as a benefit would misrepresent the analysis. Equally important is the meta-regression result: no dose-response relationship was detectable, which undercuts the argument that better outcomes are just a matter of dosing higher or more often. This literature also concerns clinical populations with neurodevelopmental disorders, not healthy adults seeking enhanced bonding, so it does not support that use even to the limited extent it supports a clinical one.

Citation

Keech B, Crowe S, Hocking DR. Intranasal oxytocin, social cognition and neurodevelopmental disorders: A meta-analysis. Psychoneuroendocrinology. 2018;87:9-19. doi:10.1016/j.psyneuen.2017.09.022.

See Also

• Parent compound: Oxytocin