An estimated one in 68 children in the United States is diagnosed with autism spectrum disorder (ASD). This neurodevelopmental condition affects social interaction and communication and is typically managed with behavioral interventions and, in some cases, medications; there is no cure. Researchers at the University of Missouri have now reported that propranolol, a medication commonly prescribed for high blood pressure and heart rhythm problems, may improve certain social communication skills in people with autism.
David Beversdorf, M.D., associate professor in the departments of radiology, neurology and psychological sciences at the University of Missouri and senior author of the study, noted that propranolol was first observed to benefit language and sociability in people with autism in 1987, though that initial report was not a randomized, controlled trial. Propranolol has also been used off-label for performance anxiety, but there has been limited rigorous investigation of its effects on autism-related social functioning until now. According to Beversdorf, this study provides the first controlled evidence that a single dose of propranolol can enhance conversational reciprocity in individuals with ASD.
In a pilot, double-blind, placebo-controlled crossover study led by Rachel Zamzow, a graduate student at the MU Center for Translational Neuroscience, 20 individuals with ASD participated in two test sessions. Each participant received either a single 40-milligram dose of propranolol or an identical placebo in one session, and the alternate treatment in the other session. One hour after administration, researchers conducted a structured conversation with each participant and rated performance across six conversational domains: staying on topic, sharing information, conversational reciprocity, managing transitions and interruptions, nonverbal communication, and eye contact.
The study found that total communication scores were significantly higher after propranolol than after placebo, with notable improvement in the nonverbal communication domain. These preliminary findings suggest that an acute dose of propranolol can enhance conversational reciprocity in people with autism, although the magnitude of effect and the mechanisms remain to be fully characterized.
Beversdorf emphasized the need for further research to determine the effects of repeated dosing and to identify which individuals are most likely to benefit. “These initial results are encouraging, but larger clinical trials that examine regular dosing schedules and longer-term outcomes are necessary before clinical recommendations can be made,” he said. Future studies could also investigate predictors of treatment response and explore how propranolol might complement behavioral therapies aimed at improving social communication.
The research team included Rachel Zamzow and Bradley Ferguson from the MU Center for Translational Neuroscience; Janine Stichter, Ph.D., from the MU Department of Special Education; Eric Porges, Ph.D., from the Department of Aging and Geriatric Research at the University of Florida; Alexandra Ragsdale from the MU Department of Biological Sciences; Morgan Lewis from the MU departments of biological sciences and psychological sciences; and senior author David Q. Beversdorf.
Funding: This work was supported by the Health Resources and Services Administration under award number 1R40MC19926. The authors note that the content is their responsibility and does not necessarily reflect the official views of the funding agency.
Source: Derek Thompson – University of Missouri-Columbia
Image Credit: The image is in the public domain
Original Research: Abstract for “Effects of Propranolol on Conversational Reciprocity in Autism Spectrum Disorder: A Pilot, Double-blind, Single-dose Psychopharmacological Challenge Study” by Rachel M. Zamzow et al., published in Psychopharmacology.
Abstract
Effects of Propranolol on Conversational Reciprocity in Autism Spectrum Disorder: A Pilot, Double-blind, Single-dose Psychopharmacological Challenge Study
Objectives
This pilot study evaluated whether a single dose of propranolol could acutely improve conversational reciprocity in individuals with ASD. The investigators also explored whether autonomic measures or anxiety levels moderated or mediated the drug’s effects, given known links between autonomic function, anxiety, and ASD.
Methods
Using a within-subject crossover design, 20 participants with ASD completed two double-blind sessions in counterbalanced order. In each session they received either 40 mg of propranolol or a placebo. One hour after ingestion, participants took part in a brief structured conversational task scored across domains of social communication. Autonomic activity and self-reported anxiety were measured before and after drug administration.
Results
Acute administration of propranolol produced a significant improvement in overall conversational reciprocity (effect size d = 0.40) and specifically in the nonverbal communication domain compared with placebo. Measures of autonomic activity and anxiety were not significantly associated with the observed drug response in this sample.
Conclusions
A single acute dose of propranolol improved conversational reciprocity in this small sample of individuals with ASD. These preliminary results warrant further study with serial dosing, larger samples, and investigation into which clinical or biological factors predict response.
“Effects of Propranolol on Conversational Reciprocity in Autism Spectrum Disorder: A Pilot, Double-blind, Single-dose Psychopharmacological Challenge Study” by Rachel M. Zamzow, Bradley J. Ferguson, Janine P. Stichter, Eric C. Porges, Alexandra S. Ragsdale, Morgan L. Lewis, and David Q. Beversdorf. Published online January 14, 2016; doi:10.1007/s00213-015-4199-0