Donald Trump and Betsy DeVos pose for photographs at Trump National Golf Club in Bedminster, N.J. AP Photo/Carolyn Kaster, File The National Advertising Division is recommending that Betsy DeVos' brain-training company remove misleading claims from its website.

Neurocore LLC advertises that it can help treat ADHD, anxiety, and depression without medication.

Such neurofeedback training is gaining popularity worldwide, but the science is far from settled.

An investigative unit overseen by the Better Business Bureau has recommended that secretary of education Betsy DeVos' brain training company, Neurocore LLC, remove claims from its website that suggest it can help treat illnesses without medication.

In a statement released Wednesday, the National Advertising Division took issue with several of the benefits that the neurofeedback company advertises on its website, including that it can help people "overcome ADHD — without drugs," "control anxiety without medication," and "strengthen your brain to fight depression — without medication."

Neurocore's CEO Mark Murrison told Business Insider that the company will appeal NAD’s decision to the National Advertising Review Board, one of the main trade organizations that regulates advertising. NAD also notes in its statement that its recommendation is not a finding of legal wrongdoing — it is ultimately up to Neurocore to remove or modify its claims.

At its core, neurofeedback essentially involves an EEG machine that gets hooked up to a video screen or set of speakers, which in turn change a sound or image in response to your brain's electrical activity. In theory, that real-time feedback could teach people how to control their brain waves and potentially improve conditions that range from ADHD to anxiety. But the science is far from settled.

DeVos maintains a stake in Neurocore estimated to be between $5 and $25 million, according to documents filed with the Office of Government Ethics and reported previously by the New York Times. That makes DeVos and her husband the company's chief investors.

Neurocore estimates that its nine centers in Michigan and Florida have treated some 10,000 clients, many of whom have ADHD, autism, or other serious learning disorders. The founder of Neurocore, Dr. Tim Royer, once served as the Chief Pediatric Psychologist at the Helen DeVos Children's Hospital, where the DeVos family still has a financial stake. Richard DeVos Sr., who owns the NBA's Orlando Magic, is one of Neurocore's most prominent clients.

Betsy DeVos served on Neurocore's board until January 2017, when her involvement raised questions among some senators about potential conflicts of interest.

Neurofeedback and ADHD

One of the most rigorously-studied applications of neurofeedback is ADHD.

But the bulk of research is still more supportive of using traditional medications like Adderall than it is for using neurofeedback training.

Two large and promising recent meta-analyses (reviews of studies) examined neurofeedback and ADHD in children. While both concluded that the treatment helped reduce children's ADHD symptoms, one said it was "probably efficacious" while the other said it was "efficacious and specific." In the first case, that phrasing corresponds to a level three out of five (3/5) on a scale that evaluates biofeedback methods (zero is the weakest and five is the strongest). In the second case, the researchers gave it a five out of five (5/5).

A few years after those studies were published, another equally large review came to the opposite conclusion, finding that the "evidence … currently fails to support neurofeedback as an effective treatment for ADHD."

Regardless, Murrison told Business Insider that Neurocore "is proud of what we do and we stand behind the outcomes we deliver to improve people’s lives."

Practitioners around the globe

Despite the lack of scientific consensus, practitioners around the globe are offering neurofeedback to clients. Many make bold claims about its ability to help treat everything from depression to PTSD.

Biocybernaut claims its neurofeedback can boost creativity and help you focus. Biocybernaut On a recent visit to a London-based neurofeedback facility run by a company called BrainTrainUK, psychologist Zuzana Radacovska explained the technology by pretending she'd just caught a glimpse of herself in a mirror and noticed she was hunching over.

"Imagine yourself standing like this and you don't realize it because you're just tired. Then suddenly you see yourself in the mirror, oops, you know, and you straighten up. This is similar. But in a good way, it's happening in the deeper structures of the brain, so it doesn't require so much conscious effort."

As the company's founder, Stuart Black, told Business Insider in April: "We're giving the brain little hints and rewards in terms of which way we'd like it to go."

Other practitioners claim that neurofeedback can make people smarter, improve their creativity, or even make them better athletes.

One neurofeedback provider, called Biocybernaut, offers exclusive, week-long, $15,000 retreats in Sedona, Arizona; Bavaria, Germany; and Victoria, British Columbia. Participants sit in darkened rooms for 12 to 14 hours a day, doing rotations of auditory and visual feedback designed to sharpen the mind. According to Biocybernaut's founder James Hardt, a week of the program will "expand your awareness more than 20 years of Zen meditation."

The scientific evidence for this type of application of neurofeedback is even more scant.

In a 2009 review, David Vernon, a professor of psychology at Canterbury Christ Church in the UK, concluded that "the notion that alpha neurofeedback can enhance the mood of healthy individuals has yet to be firmly established."

"It sounds like we're selling snake oil," Biocybernaut trainer Alice Miller told Business Insider in April. "‘It does this, does that, it even butters your toast!' But it's true. We see it every single time. [Participants] leave and they say ‘Oh my gosh how come nobody knows about this?'"