A Randomized, Placebo-Controlled, Blinded, Crossover, Pilot Study of the Effects of Dextromethorphan/Quinidine for the Treatment of Neurobehavioral Symptoms in Adults with Autism.

Prior studies have demonstrated successful irritability treatment using dopaminergic antagonists in autistic patients. The purpose of this pilot study was to assess the effect of dextromethorphan/quinidine (DM/Q) in autistic adults (18-60 years of age). This was a randomized, blinded, crossover, study of 14 patients randomized to DM/Q or a placebo for 8 weeks, washed out for 4 weeks, then crossed over to the opposite treatment.