Brain stimulation device found ineffective for managing pediatric ADHD

New research published in Nature Medicine has indicated safety but not efficacy for an FDA-cleared brain stimulation device toward managing attention-deficit/hyperactivity disorder (ADHD) symptoms.¹

The FDA cleared this device in 2019 based on results from a small study, but the device has not been approved for UK use by the National Institute for Health and Care Excellence. This larger, multicenter trial revisits the original evidence toward the efficacy of a trigeminal nerve stimulation (TNS) device for ADHD treatment.¹

“Our study shows how important it is to design an appropriate placebo condition in clinical trials of brain therapies,” said Katya Rubia, PhD, professor at King’s Collefe London.¹ “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.”

Comparing real vs sham TNS

Participants were recruited between September 2022 and November 2024, then randomized 1:1 to either an active TNS or sham TNS group based on sex, medication status, site, and age.² These patients were aged 8 to 18 years at recruitment and diagnosed with ADHD.

Additional eligibility criteria included an ADHD Rating Scale (ADHD-RS) score of at least 24, IQ greater than 70, and being able to speak English. Patients with any major psychiatric comorbidity, enuresis and encopresis, alcohol and substance abuse, traumatic brain injury, neurological abnormalities, dermatitis, or TNS contraindications were excluded.²

A 2- to 3-hour assessment was performed at baseline, during which participants measured ADHD symptoms alongside depression and anxiety, sleep, mid-wandering, emotional dysregulation, and suicidality. Neurocognitive tasks were also completed, with children receiving pupillometry during one of these tasks.²

Additional assessments and device description

Investigators also collected participant vital signs, height, and weight. Following the baseline assessment, participants completed 20- to 30- minute sessions online once a week, providing ADHD ratings from caregivers, side effects, and adverse events.²

The TNS device was returned at week 4, during which baseline tasks were completed. The assessments were also repeated at a 6-month follow-up.²

Both real and sham TNS were performed with the Monarch TNS System (NeuroSigma, Inc.), which was used for approximately 8 hours per night during sleep. The stimulator was connected to patients’ foreheads using disposable self-adhesive patch electrodes to bilaterally stimulate V1 trigeminal nerve branches.²

Stimulation with the real TNS was completed using 120-Hz repetition frequency. Weekly side effects were reported to indicate safety, while the parent-rated ADHD-RS total score was reported as the primary outcome. Teacher-rated ADHD-RS, alongside other behavioral questionnaires, were reported as secondary outcomes.²

Participants and efficacy results

There were 150 children aged a mean 12.6 years included in the final analysis, 64.7% of whom were male, 79.3% White, and 60.7% off medication. Stable stimulant medication was being taken by 39.3% of the study population at baseline, while other psychotropic medication was being taken by 12.6% and other types of medication by 13.3%.²

Both the real and sham TNS groups reported declines in ADHD-RS scores at week 4. These declines did not significantly differ, with an adjusted mean difference (aMD) of 0.83. Significant differences were also not reported at the 6-month follow-up, with an aMD of -0.29.²

Most other secondary outcomes also did not differ between groups, except for the Mind Excessively Wandering Scale total at week 4. This score was significantly improved in the real TNS group vs the sham TNS group, with an aMD of -2.17.²

Side effects and implications

Most side effects were mild and included trouble sleeping, drowsiness, headaches, and feeling nervous or hyper. Additionally, rates of side effects did not significantly differ between groups. Overall, the results indicated safety from a TNS device, but no clinical efficacy for managing pediatric ADHD.²

“It is hence paramount to control for placebo effects in modern brain therapies to avoid false hopes,” said Rubia.¹

References

1. Brain stimulation device cleared for ADHD in the US is overall safe but ineffective. King’s College London. January 16, 2026. Accessed February 3, 2026. https://www.eurekalert.org/news-releases/1112531
2. Conti AA, Bozhilova N, Eraydin IE, et al. External trigeminal nerve stimulation in youth with ADHD: a randomized, sham-controlled, phase 2b trial. Nat Med. 2026. doi.org/10.1038/s41591-025-04075-x