Beyond stimulants: a systematic review of randomised controlled trials assessing novel compounds for ADHD

Introduction: Despite stimulants being highly efficacious in short-term randomized controlled trials (RCTs), not all patients respond or can successfully tolerate them. A number of novel non-stimulant options are currently in the pipeline for the treatment of attention-deficit/hyperactivity disorder (ADHD). Areas covered: The authors conducted a systematic review of RCTs registered in ClinicalTrials.gov in the past 5 years (January 2014 and February 2019), supplemented by searches in PubMed, Web of Science, and drug manufacturer websites to find recent RCTs on novel non-stimulant ADHD medications. Expert opinion: The authors found 28 pertinent RCTs of compounds acting on a variety of biological targets, including Dasotraline, Viloxazine (SPN-812), Centanafadine SR (CTN SR), OPC-64005, Fasoracetam (NFC-1, AEVI-001), Metadoxine (MDX), Vortioxetine, Tipepidine Hibenzate, Oxytocin, Sativex (delta-9-tetrahydrocannabinol (THC) plus cannabidiol), Mazindol, and Molindone hydrochloride (SPN-810). Given the high effect size found in RCTs of stimulants in terms of efficacy on ADHD core symptoms, it is unlikely that these novel agents will show better efficacy than stimulants, at the group level. However, they may offer comparable or better tolerability. Additionally, agents acting on etiopathophysiological targets disrupted in specific subgroups of patients with ADHD will move forward the pharmacotherapy of ADHD from a 'one size fits all' to a 'precision medicine' approach.