Oxytocin Treatment on ASD: Long-Term Adverse Effects

Oxytocin (OT) is a hormone that help alter positive social feelings like generosity and trust, social communication and emotional recognition, and self-perception. Hormones are chemical messengers that allow our body cells and organs to communicate with each other and the environment. The treatment use of intranasal OT has been shown to help social developmental disorders that involve social dysfunction, including autism spectrum disorders (ASD) and schizophrenia and related disorders (schizophrenia). It has been shown that intranasal OT can increase willingness to interact socially in patients with autism, and it is already used in many clinical trials and even prescribed by health practitioners in the United States. Although acute use of OT is safe, there is little known about the long-term use of OT and few studies have been done to explore the effects. In other words, OT can produce varying effects based on its dosage and length of treatment, so it is important for finding safe and optimal strategies for future intranasal OT treatment for children with developmental disorders.

In a study done on prairie voles by Bales et al., “Chronic Intranasal Oxytocin Causes Long-Term Impairments in Partner Preference Formation in Male Prairie Voles”, results show that chronic OT treatment does indeed have long-term changes in social behavior. The study was conducted on developing prairie voles, which are rodents that are commonly used to screen potential therapeutic drugs for social disorders such as autism. The weaning voles were given one of three varying dosages of intranasal OT up until their sexual maturity. Social behavior was examined following administration, and after treatment ceased, the long-term changes in social behavior were also examined.

The results of long-term low dose treatment of intranasal OT showed that, in males, there was a decrease in bonding and a reduction of contact with other voles. In other words, social bonding was diminished and there was lower motivation to socially interact. Although there are pro-social effects of intranasal OT, short-term administration may be the safer and more effective treatment compared to chronic administration. Although the mechanism to this is not clear, it this adverse long-term effect of OT could be explained by desensitization of OT receptors in the brain. This is important for parents to know because they may believe that having their children start off with low dosages of any medicine or treatment is safer or better. In the long-term, this is not the case. Therefore, it is important to have more studies in the future to investigate the dosages, developmental timing, and timing of administration that is the best for potential OT use.

Bales KL, Perkeybile AM, Conley OG, et al. Chronic intranasal oxytocin causes long-term impairments in partner preference formation in male prairie voles. Biol Psychiatry. 2013;74(3):180‐188. doi:10.1016/j.biopsych.2012.08.025