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Lower Dose of Oxytocin Nasal Spray Improved Emotion Recognition in Adults with Autism — Higher Dose Did Not

evidence
The takeaway

A low dose of oxytocin (8 IU) delivered by a specialized nasal device significantly improved emotional face processing in autistic adults, while a higher dose showed no significant effect — the first dose-response study of oxytocin in autism.

8 IU beats 24 IU

low-dose oxytocin significantly improved emotion salience in autism (p=0.02, d=0.63) while the higher dose did not — challenging the assumption that more is better

What the researchers found

Low-dose intranasal oxytocin (8 IU) delivered via a novel Breath Powered device significantly increased emotional salience of faces in adults with autism (P=0.02, d=0.63, η²=0.18), while the higher dose (24 IU) did not reach statistical significance (P=0.12, d=0.4). Remarkably, the 8 IU effects occurred without significantly increasing blood plasma oxytocin levels, suggesting direct nose-to-brain delivery. No significant effects were found on other social-cognitive tasks (reading the mind in the eyes, emotional dot probe, face morphing).

Why it matters

Oxytocin research for autism has been hindered by inconsistent results, partly due to poor nasal delivery and unknown dose-response relationships. This is the first trial to show that less oxytocin may actually work better than more, and that a specialized delivery device can target the brain directly — potentially resolving why previous oxytocin trials in autism produced mixed results.

The numbers in context

n=17 · 8 IU vs 24 IU vs placebo · 8 IU: P=0.02, d=0.63 · 24 IU: P=0.12, d=0.4 · η²=0.18 · no blood plasma increase at 8 IU

How the study worked

Double-blind, crossover, randomized, placebo-controlled trial. 17 male adults with ASD received single doses of 8 IU oxytocin, 24 IU oxytocin, or placebo via a Breath Powered intranasal device in randomized sequence. After each dose, participants completed four social-cognitive tasks measuring emotion salience, emotion recognition, attentional bias, and face processing. Blood plasma oxytocin levels were measured.

Who was studied

17 male adults with autism spectrum disorder

What this study cannot tell us

Very small sample (n=17), all male. Single-dose crossover design cannot assess long-term effects or repeated dosing. Only one of four social-cognitive tasks showed significant improvement. The Breath Powered device is novel and not widely available. The finding of no plasma increase at the effective dose, while interesting, requires replication.

How to read the evidence

This is a well-designed double-blind, randomized, placebo-controlled crossover trial — a strong study design. However, the very small sample size (17 participants) and single-dose administration significantly limit the generalizability and clinical applicability of the findings.

When this study was published

Published in 2017, this was a pioneering dose-response study for oxytocin in autism. Subsequent research has continued to explore optimal dosing and delivery methods, informed by these findings.

The bigger picture

The oxytocin-autism field has been plagued by inconsistent results, with some trials showing benefit and others not. This study suggests two potential explanations: most trials may have used too-high doses, and standard nasal sprays may not deliver oxytocin efficiently to the brain. The Breath Powered delivery device and the finding that lower doses work better could reshape the field and explain previous contradictory results.

Questions still open

  • Would repeated low-dose oxytocin treatment produce sustained improvements in social cognition in autism?
  • Does the Breath Powered delivery device explain the results, or would standard nasal sprays at 8 IU produce similar effects?
  • Would female or non-binary individuals with autism show the same dose-response pattern?

Common questions

What is oxytocin and why is it studied for autism?
Oxytocin is a 9-amino acid neuropeptide naturally produced in the brain that plays key roles in social bonding, trust, and emotion recognition. People with autism often have differences in social processing, and oxytocin has been explored as a potential way to enhance social cognition. However, getting the right dose to the right place in the brain has been challenging.
Why did the lower dose work better than the higher dose?
This counterintuitive finding may be because oxytocin receptors respond best to moderate stimulation — too much oxytocin could desensitize them or activate different pathways. The Breath Powered device may also deliver oxytocin more directly to the brain, meaning a smaller dose achieves sufficient brain levels. This 'inverted U-shaped' dose-response pattern is seen with other neuropeptides.

Read the original research

Dose-dependent social-cognitive effects of intranasal oxytocin delivered with novel Breath Powered device in adults with autism spectrum disorder: a randomized placebo-controlled double-blind crossover trial.

Translational psychiatry, 7(5), e1136

Citation

Quintana, D S; Westlye, L T; Hope, S; Nærland, T; Elvsåshagen, T; Dørum, E; Rustan, Ø; Valstad, M; Rezvaya, L; Lishaugen, H; Stensønes, E; Yaqub, S; Smerud, K T; Mahmoud, R A; Djupesland, P G; Andreassen, O A. (2017). Dose-dependent social-cognitive effects of intranasal oxytocin delivered with novel Breath Powered device in adults with autism spectrum disorder: a randomized placebo-controlled double-blind crossover trial.. Translational psychiatry, 7(5), e1136. https://doi.org/10.1038/tp.2017.103