THURSDAY, Jan. 22, 2026 (HealthDay News) -- External trigeminal nerve stimulation (TNS) seems safe but does not demonstrate clinical efficacy for attention-deficit/hyperactivity disorder (ADHD) in children, according to a study published online Jan. 16 in Nature Medicine.Aldo Alberto Conti, Ph.D., from the Institute of Psychiatry, Psychology & Neurosciences King's College London, and colleagues conducted a confirmatory multicenter, double-blind phase 2b randomized controlled trial to examine the short- and long-term efficacy of real versus sham TNS in 150 children and adolescents with ADHD (mean age, 12.6 years). Participants were randomly assigned to receive real and sham TNS (75 participants in each group) nightly for about nine hours for four weeks. V1 trigeminal branches were targeted by bilateral stimulation using battery-powered electrodes applied to the forehead, while in sham TNS, 30 seconds of simulation per hour was delivered at lower frequency and pulse width.The researchers observed no significant differential treatment effects on ADHD symptoms in the intention-to-treat analysis. There were no reports of serious adverse events and no between-group differences in side effects."Our study shows how important it is to design an appropriate placebo condition in clinical trials of brain therapies," senior author Katya Rubia, Ph.D., also from the Institute of Psychiatry, Psychology & Neurosciences King's College London, said in a statement. "There is a large placebo effect with high-tech brain therapies, in particular for patients and families that have an expectation that they can adjust brain differences associated with ADHD. It is hence paramount to control for placebo effects in modern brain therapies to avoid false hopes."Several authors disclosed ties to the pharmaceutical and biotechnology industries.Abstract/Full Text.Sign up for our weekly HealthDay newsletter