External trigeminal nerve stimulation versus sham stimulation for attention deficit hyperactivity disorder in children and adolescents aged 7-17 years: study protocol for a pilot and feasibility randomized clinical trial

External trigeminal nerve stimulation (eTNS) is a non-invasive technique involving external cutaneous stimulation of the trigeminal nerve. In 2019, the Monarch eTNS device was approved as a treatment for children with attention-deficit/hyperactivity disorder (ADHD). The Monarch eTNS device is designed to be applied at home, which offers a certain level of convenience but also necessitates a high degree of compliance and acceptability from the families. To assess the feasibility of - and pilot a larger randomized clinical trial investigating the Monarch eTNS device versus sham for patients aged 7 to 17 years with ADHD. We will conduct a parallel-group, sham-controlled, feasibility randomised clinical trial. We will include 60 children and adolescents (aged 7 to 17 years) diagnosed with ADHD from three clinical sites in Denmark. Patients will be randomised to 4 weeks of active versus sham eTNS. Feasibility outcomes include completion of the trial; the number of eligible participants who consent to inclusion; treatment compliance; acceptability of the intervention and completion. Adverse events will be monitored throughout the trial. Exploratory clinical outcomes include ADHD core symptoms (primary) and several secondary outcomes. Autonomic functions will be evaluated by means of heart rate variability, using a heart rate sensor. This trial will allow us to evaluate the feasibility of conducting a larger randomised clinical trial investigating the use of eTNS as a home-based, non-pharmacological intervention for children and adolescents diagnosed with ADHD.Trial registration: ClinicalTrials.gov ID: NCT06655610. Registered 23.10.2024.