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

Friday, May 12, 2017: 5:00 PM-6:30 PM
Golden Gate Ballroom (Marriott Marquis Hotel)
S. Bernaerts1,2, C. Dillen3, J. Steyaert2,4 and K. Alaerts2,3, (1)Rehabilitation Sciences, University of Leuven, KU Leuven, Leuven, Belgium, (2)University of Leuven, Leuven Autism Research consortium, Leuven, Belgium, (3)Department of Rehabilitation Sciences, University of Leuven, KU Leuven, Leuven, Belgium, (4)Department of Neurosciences, University of Leuven, KU Leuven, Leuven, Belgium

Autism spectrum disorders (ASDs) are characterized by impairments in social communication and interaction and repetitive and restricted behaviors. To date, no pharmacological treatment exists targeting the core symptoms of ASD, yet the past years, the pharmacological use of a neuropeptide, called oxytocin (OT), has gained increasing interest from the research community to explore its potential for elevating the core social deficits in ASD. OT is known to play a pivotal role in a variety of complex social behaviors by promoting a prosocial attitude and interpersonal bonding. Previous studies showed that exogenously administered OT can affect trust and feelings of attachment insecurity, reduce repetitive and restricted behaviors and increase social cognition.


A double-blind randomized placebo-controlled trial with thirty-four young adult men with ASD (17 OT/ 17 Placebo (PL)) was conducted to assess behavioral effects of OT therapy (i) at baseline; (ii) after four weeks of daily nasal spray administration; and (iii) four weeks post-treatment to assess potential retention effects.


Doses of 24 IU oxytocin (Syntocinon®, Sigma-tau) or placebo nasal spray (PL) (saline natrium-chloride solution) (3 puffs in each nostril) were administered daily for four weeks.

Primary outcome measures to assess treatment effects included the Social Responsiveness Scale (SRS) and the Repetitive Behavior Scale – Revised (RBS-R). Secondary outcome measures included assessments of changes in attachment (State Adult Attachment Scale (SAAM); Inventory of Parent and Peer Attachment (IPPA)); assessments of changes in mood state (Profile of Mood States questionnaire (POMS)); and assessments of changes is reports of quality of life (World Health Organization Quality of Life questionnaire (WHOQOL)). All participants were characterized using IQ and ADOS-scales. Thirty-four male individuals with ASD are currently enrolled in the study and recruitment is still ongoing.


After four weeks of OT nasal spray administration, self-reports on repetitive and restricted behaviors (RBS-R) were shown to be tentatively reduced in the OT group, not in the PL group (F(1, 31)=3.83, p=0.06) and of note, the effect of OT persisted until one month after the treatment (retention: F(1, 31)=4.02, p=0.05). Immediately after the four weeks of treatment, we found no significant effects of OT on social functioning as assessed using self- and informant-based reports of the SRS. Interestingly however, at the retention session, a significant effect was revealed for the informant-based SRS (F(1, 22)=4.90, p=0.04), indicating that clear improvements in social responsiveness emerged one month after cessation of the actual treatment (specifically for 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, indicating improvements in self-reports of attachment immediately after the four-week treatment (F(1, 32)=3.32, p=0.08) (IPPA) and improvements in the experience of social relationships at the retention session one-month post-trial (F(1, 31)=3.07, p=0.09) (WHOQOL).


The observed improvements after four weeks of daily treatment with intranasal OT in our primary outcome measures (assessing social responsiveness and repetitive and restricted behaviors) indicate that OT can induce long-term behavioral changes in individuals with ASD that outlast the time of intervention.