A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Fall, 2020 | Number 4, Volume 34

Oxytocin may cause long-term amygdala changes, improvements in social functioning in ASD

A new study from Belgium indicates that administering intranasal doses of the hormone oxytocin to adult men with autism spectrum disorders (ASD) may result in long-term improvements in social functioning as well as changes to regions of the brain involved in emotion. 

The double-blind, randomized, placebo-controlled study, conducted by Sylvia Bernaerts and colleagues, included 38 men with ASD, ranging in age from 18 to 35 years. In the study, the researchers measured: 

• The immediate effects of a single dose of intranasal oxytocin. 

• The short- and long-term effects of multiple doses of intranasal oxytocin taken daily for four weeks. 

To measure the effects of oxytocin administration, the researchers asked participants to engage in an emotion-processing task while undergoing functional magnetic resonance imaging. They also assessed the men’s social functioning and repetitive behaviors before and after treatment. 

Bernaerts and colleagues found that oxytocin administration resulted in attenuation of activity in the amygdala, which is part of the brain’s threat-processing circuit. This attenuation was significant four weeks after the treatment and one full year later. 

Furthermore, the researchers say, their analysis showed that “participants with stronger attenuations in amygdala activity showed greater behavioral improvements, particularly in terms of self-reported feelings of avoidant attachment and social functioning.” Improvements in repetitive behavior were also seen. 

The researchers also detected an increase in activity of the posterior superior temporal sulcus (pSTS), which is involved in socio-communicative processing, in response to the single dose of oxytocin. However, they say that “no consistent long-term changes in pSTS activity were induced after the multiple-dose treatment.” 

“Together,” the researchers say, “these findings indicate that a four-week intranasal oxytocin treatment can induce long-lasting neural changes in core social brain regions.” 


Citations

“Oxytocin treatment attenuates amygdala activity in autism: a treatment-mechanism study with long-term follow-up,” Sylvia Bernaerts, Bart Boets, Jean Steyaert, Nicole Wenderoth, and Kaat Alaerts, Translational Psychiatry, November 2020 (free online). Address: Kaat Alaerts, [email protected].