The Effects of Four Weeks of Intranasal Oxytocin on Social Responsiveness and Repetitive and Restricted Behaviors in Autism Spectrum Disorders: A Randomized Controlled Trial

The Effects of Four Weeks of Intranasal Oxytocin on Social Responsiveness and Repetitive and Restricted Behaviors in Autism Spectrum Disorders: A Randomized Controlled Trial. Sylvie Bernaerts, Claudia Dillen, Jean Steyaert, and Kaat Alaerts Background: Autism spectrum disorders (ASDs) are characterized by impairments in social interaction and repetitive and restricted behaviors (RRBs). To date, no pharmacological treatment exists targeting the core symptoms of ASD, yet the pharmacological use of the neuropeptide oxytocin (OT) has gained interest from the research community to explore its potential for elevating social deficits in ASD. Methods: A double-blind randomized placebo-controlled trial with thirty-four young adult men with ASD (17 OT/17 Placebo) was conducted to assess behavioral effects of OT therapy (i) at baseline; (ii) after four weeks of therapy; and (iii) four weeks post-treatment (follow-up). Doses of 24 IU oxytocin (Syntocinon®, Sigma-tau) or placebo nasal spray were administered daily for four weeks. Primary outcome measures included the social responsiveness scale (SRS) and the repetitive behavior scale (RBS-R). Secondary outcome measures included questionnaires assessing attachment, mood state and quality of life. Results: After four weeks of OT administration, self-reports on RRBs showed tentative reductions in the OT group (F(1,31)=3.83, p=0.06) and this effect persisted until one month after treatment F(1,31)=4.02, p=0.05). No significant changes in social responsiveness were observed immediately after the four-week OT treatment, but interestingly, at the 1-month follow-up session, significant improvements were revealed for the informant-based SRS report, indicating clear improvements in reports of social motivation (F(1,22)=4.71, p=0.04) and social communication (F(1,22)=7.39, p=0.01). For the secondary outcome measures, only tentative effects were revealed. Conclusions: The observed improvements after the four-week OT treatment in social responsiveness and RRBs indicate that OT can induce long-term behavioral changes in individuals with ASD.status: publishe