The investigators' specific aim is to examine the effects of serial doses of propranolol on social interaction, and secondarily on language tasks, anxiety, adaptive behaviors, and global function in high functioning adults and adolescents with autism in a double-blinded, placebo-controlled trial. The investigators will also examine whether response to treatment can be predicted based upon markers of autonomic functioning, such as skin conductance and heart rate variability, and whether anxiety predicts treatment response. The investigators' hypothesis is that social functioning and language abilities will benefit from serial doses of propranolol, as the investigators have demonstrated in previous single-dose studies. The investigators also predict that those with the greatest degree of autonomic dysregulation will demonstrate the greatest benefit from the drug.
The purpose of this study is to explore the effects of propranolol on social interaction, and secondarily on language, anxiety, adaptive behaviors, and global function in high functioning adults and adolescents with autism in a double-blinded, placebo-controlled pilot trial.