Health IT, Hospitals

Safety concerns spur doctors, scientists to engage brain stimulation technology hackers

At the center of the scientists’ concerns is the lack of studies of transcranial direct stimulation at the frequencies many end users experiment with — for example, stimulating daily for months or longer.

The rise of the do-it-yourself brain stimulation movement has long been a source of consternation in the medical community. So-called transcranial direct stimulation (tDCS), also known as “brain zapping,” involves delivering small currents of electricity to the brain via electrodes placed on the head. Such devices are easy to make at home.

Recently 39 doctors and academics signed an open letter to the tDCS community in the Annals of Neurology, warning of the risks of the approach to (hopefully) improving cognition or treating conditions like depression.  The authors are concerned that their studies are unintentionally driving interest in tDCS among everyday people, leading to the creation of a “movement” that could end up harming its subjects. They felt an “ethical obligation” to inform “both professionals and DIY users to some of these issues.”

“We realized that there was a big disconnect between the academic interpretation of the literature and the way lay-users interpret things,” said letter co-author Dr. Michael Fox, assistant professor of neurology at Harvard Medical School and director of the laboratory for brain network imaging and modulation, in a phone interview.

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At first I was a little skeptical that ordinary people would read articles in the journals like Frontier in Systems Neuroscience, but then I realized that websites like Reddit provide a conduit for dissemination of articles and interpretations (and misinterpretations). Check out this thread on whether tDCS can treat atrial fibrillation.

Fox said that while DIYers are inspired by the latest experimental results, they don’t perform the technique in the same way as in studies. “We have never formally studied tDCS at the frequencies many DIY users experiment with—for example, stimulating daily for months or longer. Because we know that stimulation from just a few sessions can be quite lasting, we infer that changes induced by these protocols may be even more so. We do not know yet whether such changes are reversible, and the possible risks of a cumulative dose over years or a lifetime have not been studied,” the letter says.

Other issues to be resolved include the effect of stimulation on unintended areas of the brain, the effect of tDCS parameters on outcomes and the variability of tDCS across different people.

Several companies are aiming to capitalize on the rise of noninvasive brain stimulation by offering their own commercial devices., maker of “the world’s most advanced electrical brain stimulator,” did not respond to a request for comment, while Thync said its wearable head patch does not perform tDCS.

The device also modulates the brain, but uses transcranial pulsed ultrasound, instead of electrical stimulation.

Neither device is regulated by the FDA because they are considered “lifestyle products,” and not intended to diagnose or treat any disease. says its device can enhance the odds of lucid dreaming, while Thnyc’s motivation vibe will encourage you to “get off the couch and get pumped to crush your workout,” according to the website.

“There is a different level of acceptable risk when trying to treat a brain disease versus enhancing a brain that’s already healthy,” Fox said, though he wouldn’t take a position on FDA regulation of commercial devices.

Unintended consequences pose some of the biggest risks. “It’s possible that whatever we do or treat with tDCS will come at the cost of something else,” he said, adding, “There’s data to suggest that those tradeoffs might be more common than we think.”

For example, among the myriad studies cited in the open letter is one which found that tDCS “can enhance the rate of learning new material, but at the cost of processing learned material, and vice versa, depending on the stimulation site.”
Certain tradeoffs may be acceptable to treat depression, but the less drastic (and more difficult to prove) benefit of improvement in cognition is more easily overwhelmed by potential harm to the brain, Fox explained.

“It’s not always obvious what the modulation is doing,” he said.

While the authors claim the letter is meant for both professionals–who use iontophoresis devices on an off-label basis to perform their research on tDCS–and the DIY community, it’s fair to say that the latter group is the intended audience.

In fact, one of the authors sparked a rollicking conversation on Reddit by initiating a thread about the letter. He emphasized that the point of the document was not to tell people what to do, but to provide information.

Some do-it-yourself movements have proven constructive, like the one in the diabetes community, whose ideas and innovations are being integrated into commercial products. So perhaps the academics’ outreach to the lay people will prove fruitful.

While its role as a lifestyle enhancer is unproven and controversial, non-invasive brain stimulation continues to gain ground in specific therapeutic areas. The FDA just approved the first focused ultrasound device for the treatment of essential tremor in patients who have not responded to medication.

Photo: Flickr user Yumlkrum