Intranasal Oxytocin Doubles Social Interaction Time in Autism Mouse Model, With Effects Lasting 4 Weeks After Treatment Ends

Daily intranasal oxytocin (0.8 IU/kg for 4 weeks): 2x more social interaction time from week 2. 50% reduced explorative behavior at 4 weeks. 30% reduction in repetitive behavior persisting 4 weeks post-treatment. Effects lasted 4 weeks after treatment ended. However, ~10% increase in social disinterest also observed.

Animal study using Shank3-/- adult mice (genetic autism model). Daily intranasal oxytocin (0.8 IU/kg) for 4 weeks. Behavioral testing during treatment (weeks 2, 4) and post-treatment (4 weeks after cessation). Outcomes: social interaction time, explorative behavior, repetitive behaviors, social disinterest. Published in Molecular Psychiatry.

ASD core symptoms (social deficits, repetitive behaviors) have no approved pharmacological treatment. Oxytocin has long been a candidate, but clinical trial results have been ambiguous. This study in a genetic model shows clear, lasting benefits — but also reveals concerning social ambivalence that may explain mixed clinical results and demands careful investigation.

The persistence of oxytocin's effects for 4 weeks after stopping treatment suggests it may produce lasting changes in social brain circuits, not just acute pharmacological effects. This has important implications for clinical trial design — intermittent oxytocin treatment might be sufficient. However, the social ambivalence finding adds nuance to the simplified narrative of oxytocin as a purely 'prosocial' neuropeptide.

Mouse model — Shank3 knockout represents only a subset of ASD. Behavioral tests may not fully capture human social complexity. The 10% increase in social disinterest is concerning and poorly understood. No dose-response or long-term safety data. Intranasal delivery in mice differs from human nasal anatomy.