Abstract Details

Autism spectrum disorder (ASD) is characterized by impaired social interaction and communication as well as repetitive behaviors and restricted interests.  Current pharmacotherapy targets psychiatric comorbid conditions, and no agent is proven to target the core features.  Past trials were frequently characterized by a high degree of individual variability of response to drugs. Propranolol is a non-selective beta-adrenergic antagonist, often used to treat performance anxiety. Our previous work found propranolol improved conversational reciprocity in patients with ASD with a single dose psychopharmacological challenge study.  Herein we examine whether psychophysiological measures predict response to propranolol on conversational reciprocity in ASD in an open-label extension of a clinical trial.

Forty-seven ASD participants, age 7-24 titrated propranolol to 100mg a day in divided doses, or a body weight adjusted dose in younger children.  Baseline heart rate variability (HRV) was assessed, and social reciprocity from the General Social Outcomes Measure (GSOM) at baseline and 12-weeks.  HRV measures were correlated with change in performance on social reciprocity from the GSOM, performed separately for participants ages 7-14 and ages 15-24 due to changes in psychophysiology across development.

For 7-14 year old participants, there was a significant negative correlation between change in conversational reciprocity and baseline standard deviation of the heart rate (Pearson’s r = -0.490, p = 0.018, n = 24).  This was not observed in older participants.

Psychophysiological markers associated with arousal and sympathetic/parasympathetic balance appear to predict response to propranolol on aspects of social interaction.  Larger trials will need to confirm the apparent specificity to the younger population, and establish broader understanding of markers predicting best responders to propranolol in ASD.