Editorial: Targeting the Core Symptoms of Autism Spectrum Disorder With Mechanism-Based Medications.

Medications can help manage behavioral problems associated with autism spectrum disorder (ASD), but no pharmacological treatment has proved effective for the core symptoms of the disorder. The article by Sprengers et al.1 in this issue of the Journal reports the primary results of the randomized clinical trial Bumetanide in Autism Medication and Biomarker (BAMBI), which tested the efficacy of bumetanide, a loop diuretic acting as a selective antagonist of the chloride importer NKCC1, for the core symptoms of ASD in 92 children 7-15 years of age.1 The study by Sprengers and colleagues was carefully designed and powered to detect a medium treatment effect size. Great attention was paid to protecting the blindness of the experiment in light of the adverse effects of the medication. After the 3-month treatment, bumetanide was not better than placebo at decreasing social communication deficits, as measured with the Social Responsiveness Scale-2 (the primary outcome), although a decrease in repetitive behaviors (a secondary outcome) was found. This study attests to the progress from clinical serendipity to pathogenesis-driven treatment research in ASD and is remarkable in a number of ways.