A major new study led by King’s College London has found that a device approved in the U.S. to treat ADHD does not help reduce symptoms in children and teens.
The device uses a technique called trigeminal nerve stimulation, or TNS, which was cleared by the U.S. Food and Drug Administration (FDA) in 2019 after a smaller trial showed promising results.
But this new trial, published in the journal Nature Medicine, involved 150 children and teenagers aged 8 to 18 and found no meaningful improvement in ADHD symptoms. Researchers say the FDA should take another look at the earlier data that led to the device’s approval.
TNS works by sending small electrical pulses through a facial nerve called the trigeminal nerve. This nerve connects to areas of the brain involved in attention and alertness. The idea is that stimulating the nerve can help reduce symptoms like inattention and hyperactivity, which are common in ADHD.
The first study, which helped get the device approved in the U.S., tested it on just 62 children and used a simple comparison group that received no stimulation.
There were also questions about how well the study was blinded, meaning whether participants or researchers could tell who got the real treatment. These issues raised concerns that the original results might have been influenced by a placebo effect.
To address this, the new trial used a more careful design. It was conducted at two sites—one in London and one in Southampton—and included a more diverse group of children and teenagers.
Half the participants received real TNS every night for four weeks, with electrodes attached to their foreheads for about nine hours. The other half received a placebo version of the treatment, with the device only turning on briefly each hour at levels that were too low to be effective.
Researchers carefully measured changes in ADHD symptoms, including attention, hyperactivity, mood, sleep, and mind-wandering. The results showed no difference between the real treatment and the placebo. Although the device was safe and most kids didn’t mind using it, it did not lead to any real improvement in symptoms.
Professor Katya Rubia, one of the senior researchers, said the findings highlight how important it is to include a good placebo group in trials of brain therapies. High-tech treatments can create high expectations, which makes it even more important to carefully control for placebo effects.
Dr. Aldo Conti, lead author of the study, explained that this trial fixed the problems seen in the earlier study. It included older children, used better controls, and showed that the earlier positive results may not hold up under stricter testing.
Professor Samuele Cortese, the study lead in Southampton, emphasized that good science is essential when choosing ADHD treatments. Families need to know what works and what doesn’t, and this study gives them better information to make those choices.
The trial involved several NHS mental health services across England and was coordinated by the King’s Clinical Trials Unit. It was one of the largest and most carefully controlled studies of its kind.
While the TNS device is approved in the U.S., it is not currently recommended in the UK by health authorities such as NICE. These new findings suggest that the original FDA approval may need to be reviewed, especially since the device didn’t show clear benefits in this more rigorous trial.
For families and clinicians looking for ADHD treatments, this study serves as an important reminder: even treatments that sound promising need to be tested carefully before they are used widely.
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