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In A Nutshell
• A brain stimulation device cleared by the FDA in 2019 failed to beat placebo in a rigorous 150-participant trial of children and teens with ADHD
• Both real and fake treatments led to major improvements (26% and 29%, respectively), likely due to strong placebo effects from believing in neurotechnology
• The device is safe with mostly mild side effects, but safety alone doesn’t justify using an ineffective treatment
• The findings reveal problems with FDA clearance based on small studies with weak control groups, leaving families investing in treatments that may not actually work
Parents searching for alternatives to ADHD medication are sure to be disappointed by this report. A major trial found that a nerve stimulation device cleared by the FDA in 2019 performed no better than a placebo at reducing symptoms in children and teenagers with attention-deficit/hyperactivity disorder.
The study tested external trigeminal nerve stimulation, or TNS, which works by sending electrical pulses through patches placed on the forehead during sleep. The device received FDA clearance based on promising results from a small pilot study of 62 children. However, when researchers tested it among 150 kids and teens over four weeks (half with the real treatment and half with a fake placebo), both groups improved by almost exactly the same amount.
Parents reported symptoms dropped by 26% in the real treatment group and 29% in the placebo group. That’s right, the fake treatment actually performed slightly better, though the difference wasn’t statistically meaningful.
Why Parents Wanted This to Work
It’s easy to understand the appeal. ADHD medications like Ritalin and Adderall help about 70% of kids, but they can cause appetite loss, sleep problems, and mood changes. Teenagers especially tend to stop taking their pills over time. A device you wear during sleep, avoiding daily medications entirely, sounds like an attractive solution.
The science behind TNS made sense too. The device targets nerves on the forehead that connect to brain regions involved in attention and arousal. Researchers thought stimulating these nerves might activate the locus coeruleus, a brain structure that releases noradrenaline and helps with focus.
Unfortunately, the hypothesis didn’t pan out. The study, published in Nature Medicine, tested everything from parent ratings and vigilance tasks to wrist-worn sensors measuring actual movement. Nothing showed real benefits over fake treatment. Kids who got real TNS did report less mind-wandering, but that single finding among many measures tested may be a statistical fluke.
The Power of Believing in Technology
Interestingly, both groups improved dramatically, far more than you’d typically see with a placebo in ADHD medication trials. The placebo group’s improvement was equivalent to what researchers call a “large effect size” of 0.9, more than twice the usual placebo response.
Why? The researchers point to something called “neuro-enchantment.” When families think they’re getting cutting-edge brain stimulation technology, that belief alone can create real changes. Parents might notice improvements more readily. Kids might feel more confident and focused simply because they’re doing something high-tech to help their brains.
The earlier 2019 study that convinced the FDA suffered from a critical flaw: its placebo treatment delivered zero actual stimulation. Parents and kids could probably tell they were in the placebo group because they felt nothing at all. This new study fixed that by having the placebo device deliver brief, low-intensity pulses once per hour. Both groups felt something, making it nearly impossible to guess who got what. Once participants truly couldn’t tell if they were receiving the real treatment or not, the placebo effect skyrocketed.
After four weeks, most participants genuinely didn’t know which treatment they’d received. Neither did the researchers doing the assessments. That’s good science, but it revealed an uncomfortable truth: the real device didn’t outperform the fake one.
What Happened During the Trial
Researchers recruited 150 children and adolescents with confirmed ADHD from clinics around London, Southampton, and Portsmouth. All had moderate to severe symptoms. About 40% were taking ADHD medications, while 60% were medication-free. Half got real TNS, half were given placebo treatments, and everyone wore devices each night during sleep over four weeks.
Compliance was high. Some 93% of families stuck with it, and most reported no side effects or only mild ones. The most common complaints were headaches (reported by about 20% in both groups) and sleep problems (20% in the real group, 9% in the placebo group). Six kids stopped using the device early (three in the real group due to nightmares, sleep issues, or increased hyperactivity), though all stayed in the study.
What This Means for Families
The negative findings align with other disappointing results from brain stimulation techniques tested for ADHD. Transcranial magnetic stimulation hasn’t panned out. Neither has transcranial direct current stimulation. At some point, the pattern becomes clear.
Perhaps the bigger issue is what this reveals about FDA clearance. The agency greenlit this device based on that small 2019 study with weak blinding. When researchers did a proper test with better controls, the initial promising results evaporated. That’s a problem for families who invested time, hope, and money into a treatment that ultimately doesn’t work.
For parents exhausted by medication side effects or kids who refuse to take pills, this may be frustrating news. The appeal of a nighttime device that works while your child sleeps is obvious. While the benefits families saw were real (both groups improved significantly), since the groups improved equally, those gains likely came from placebo effects and being in a study rather than from the device itself. The search for effective non-medication ADHD treatments continues.
Disclaimer: This article is for informational purposes only and is not intended as medical advice. Parents and caregivers should consult with qualified healthcare providers before making decisions about ADHD treatment options. Do not stop or modify prescribed medications without consulting your child’s doctor.
Paper Summary
Limitations
The study had an 80% rate of missing data for teacher ratings because few teachers participated in providing assessments. Parent ratings can be influenced by various biases including parental stress and demographic factors. Although adherence was very high at 93%, it relied on self-reported nightly sleep diaries rather than objective device logging, as device-logged usage data proved unreliable. The inclusion of medicated children (40% on stable stimulant medication) could theoretically have masked treatment effects, though subgroup analysis of unmedicated children showed the same null results. The trial was limited to four weeks of treatment and a six-month follow-up, so longer-term effects beyond this period remain unknown.
Funding and Disclosures
This project was funded by the Efficacy and Mechanism Evaluation Programme (NIHR130077), a Medical Research Council and National Institute for Health and Care Research partnership. Additional support came from the NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. Several authors received funding from other NIHR grants, the Medical Research Foundation, and the Rosetrees Foundation. The design, management, analysis, and reporting of the study were independent of the funders and device manufacturers. Samuele Cortese reported honoraria from Medice. Mitul Ashok Mehta reported research funding and consulting relationships with pharmaceutical companies including Takeda, Johnson and Johnson, Lundbeck, Boehringer Ingelheim, and Nxera. Paramala Santosh reported research funding, consulting fees, and stockholdings related to various pharmaceutical companies and HealthTracker, Ltd. Ben Carter received funding from LifeARC and Mundipharma. Other authors declared no competing interests.
Publication Details
Aldo Alberto Conti, Natali Bozhilova, Irem Ece Eraydin, Dominic Stringer, Lena Johansson, Robert Marhenke, Andrea Bilbow, Sahid El Masri, Joshua Hyde, Giovanni Giaroli, Holan Liang, Federico Fiori, Mitul Ashok Mehta, Paramala Santosh, Ben Carter, Samuele Cortese, and Katya Rubia. “External trigeminal nerve stimulation in youth with ADHD: a randomized, sham-controlled, phase 2b trial.” Published January 16, 2026 in Nature Medicine. DOI: 10.1038/s41591-025-04075-x. Author affiliations include Department of Child & Adolescent Psychiatry at King’s College London, Centre for Innovation in Mental Health at the University of Southampton, and multiple other UK and international institutions.
