5 December 2006

Oxytocin Touted As Autism Treatment

by Kate Melville

The annual meeting of the American College of Neuropsychopharmacology has been told that oxytocin may have significant positive effects on adult autism patients. The study examined the effects of oxytocin - sometimes referred to as the trust drug - on repetitive behaviors and aspects of social cognition in adults with autism.

Researcher Eric Hollander, from the Mt. Sinai School of Medicine, believes that autism could be a good candidate for treatment with oxytocin as it presents with the types of symptoms that have been found to be associated with oxytocin. "[Past] studies with animals have found that oxytocin plays a role in a variety of behaviors, including parent-child and adult-to-adult pair bonding, social memory, social cognition, anxiety reduction and repetitive behaviors," said co-researcher Jennifer Bartz, also from the Mt. Sinai School of Medicine.

In the study, adults with autism or Asperger's disorder received an intravenous infusion of pitocin (synthetic oxytocin) or placebo (saline solution) over a four-hour period. During that time, participants were monitored for repetitive behaviors that are hallmarks of autism spectrum disorders including need to tell/ask, touching, and repeating. These behaviors were assessed at a baseline and throughout the course of the infusion. "Repetitive behaviors are often overlooked as symptoms of autism in favor of more dramatic symptoms like disrupted social functioning," explained Hollander. "However, early repetitive behavior is often the best predictor of a later autism diagnosis."

The study found that the infusion produced results that were both clinically and statistically significant. Hollander noted a rapid reduction of repetitive behaviors over the course of the oxytocin infusion, whereas no such reduction occurred following the placebo infusion.

The researchers also looked at the effects of oxytocin on social cognition (autism patients are often unable to detect or read emotion in others through facial and voice cues). To test the participants' ability to assign significance to speech, participants listened to pre-recorded sentences with neutral semantic content that were presented with different intonations such as anger, sadness, or happiness. Participants were then asked to identify the emotion. Interestingly, participants who received oxytocin on the first testing day retained the ability to assign affective significance to speech when they returned approximately two weeks later. This effect was not found among participants who received the placebo on the first testing day.

Hollander and his colleagues are among the first to have used both intravenous and nasal delivery to study the behavioral effects of oxytocin in autism spectrum disorders. Though the findings are promising, Hollander cautions that this research is still very preliminary. "Our findings will need to be replicated in large scale, placebo controlled trials to fully explore treatment potential," said Hollander. "And, though both intravenous and intranasal approaches have been well tolerated, we need to understand more about the safety of these potential treatments, particularly before these effects are explored in autistic children."

Source: American College of Neuropsychopharmacology