A systematic review on the efficacy of the neuropeptides oxytocin and vasopressin in the treatment of autism spectrum disorder

Abstract

The aim of this review is to examine the efficacy of neuropeptides OXT and Vasopressin administration on amelioration of core symptoms of ASD as a pharmacological treatment. The objectives are to assess the effect of the mentioned two neuropeptides on the ASD core symptoms, to provide an understanding of the hypothetical neural mechanism underlying the action of OXT and Vasopressin, and to critically evaluate existing data from RCTs to interpret efficacy compared to placebo among individuals with ASD. The search methodology for RCTs were supplemented from PubMed and from manual searching in the bibliographies of relevant papers. 9 RCTs were included in this review which examined social cognition and repetitive behavior as target symptoms of ASD. In terms of oxytocin, only 2 studies reported improvement in key symptoms and for vasopressin, one study used arginine-vasopressin and demonstrated a trend of improvement while the outcomes from rest 3 studies that utilized vasopressin antagonist as treatment intervention suggested minor advancements in social communication but no significant between group differences. The studies included in this paper had a medium to high risk of bias. Our review yielded mixed findings about the efficacy of vasopressin and oxytocin, and due to the small number of RCTs included, our findings should still be seen as tentative.