A widely-available medication may be able to significantly improve conversation skills in individuals with autism with as little as one dose, a new study suggests.

Those with high-functioning autism who took the beta-blocker propranolol showed greatly improved communication abilities just an hour after taking a 40-milligram dose, according to findings published online recently in the journal Psychopharmacology.

“While its intended use is to treat high blood pressure, propranolol has been used off-label to treat performance anxiety for several years. However, this is the first study to show that a single dose of propranolol can improve the conversational reciprocity skills of individuals with autism,” said David Beversdorf, an associate professor at the University of Missouri and a senior author of the paper.

For the study, 20 people with autism were given either the dose of propranolol or a placebo. An hour later, researchers had a conversation with the study participants who got to choose whether to chat about their plans for the weekend or hobbies.

The individuals with autism were assessed on their ability to stay on-topic, share information, maintain eye contact, participate in nonverbal communication, share the conversation and deal with transitions or interruptions. Participants were also monitored using electrocardiography and they completed questionnaires about their anxiety level before and after taking the medication.

Subsequently, study participants came for a second visit where they were given propranolol or a placebo – whichever they did not receive the first time – and assessed again.

Overall, researchers found that scores on nearly every measure of conversation skills improved when the individuals had taken propranolol as compared to the placebo.

“Though more research is needed to study its effects after more than one dose, these preliminary results show a potential benefit of propranolol to improve the conversational and nonverbal skills of individuals with autism,” Beversdorf said. “Next, we hope to study the drug in a large clinical trial to establish the effects of regular doses and determine who would most likely benefit from this medication.”