Month: October 2022

Imagine this as a morning routine that replaces your first cup of coffee:

You wake up feeling a bit foggy, so you slip on a wearable device that looks like an extra-thick headband. You turn on the power source and settle in while electrical current flows into your brain. Twenty minutes later, feeling more focused and energized, you start your busy day feeling grateful for this new technology.

If this scenario sounds strange to you, I’m with you. And yet, hype around transcranial direct current stimulation (tDCS) is growing for an expanding list of conditions such as depression, ADHD, and even Alzheimer’s disease. A recent ad for one tDCS device urges you to “elevate your performance.” But before you give this a try, read on.

What is transcranial direct current stimulation?

Brain stimulation therapies aim to activate or inhibit parts of the brain. tDCS has been around for years, but its popularity has spiked over the last decade.

tDCS devices use headgear that may look like a swim cap or headband to position electrodes against the scalp. When a power source is switched on, the electrodes deliver low levels of electrical current to the brain. A typical session lasts 20 to 30 minutes and may be repeated over days or weeks.

Three better-known brain stimulation therapies are:

• Transcranial magnetic stimulation (TMS): A device worn over the forehead stimulates specific areas of the brain by changing nearby magnetic fields. TMS is cleared by the FDA to treat depression that hasn’t responded to standard medicines, and for obsessive-compulsive disorder.
• Electroconvulsive therapy (ECT): An electric current flowing through electrodes placed at specific locations on the scalp causes a brief seizure while a patient is under anesthesia. In use since the late 1930s, ECT can be highly effective for severe depression that hasn’t responded to standard therapies. It uses higher levels of electrical current than tDCS. That’s why it requires close medical supervision and is generally administered in a hospital or specialized clinic.
• Deep brain stimulation (DBS): Electrodes surgically implanted in specific areas of the brain generate electrical pulses. DBS is used to treat conditions such as Parkinson’s disease, epilepsy, or tremors that don’t improve with medicines.

What claims are made for tDCS?

The brain normally functions by sending and receiving tiny electrical signals between nerve cells. Stimulating specific regions of the brain with low levels of electricity might improve focus or memory, mood, or even dementia, according to tDCS advocates.

Some claims say tDCS can

• improve mental clarity, focus, and memory
• increase energy and motivation
• relieve so-called brain fog following COVID-19, Lyme disease, or other conditions
• reduce depression or anxiety
• reduce cravings among smokers or people with drug addiction
• improve symptoms of ADHD or Alzheimer’s disease.

Does tDCS work?

The jury is still out. Research suggests that tDCS holds promise for certain conditions, but techniques tested through research may differ from devices sold commercially for at-home use. For example, electrodes may be positioned more precisely over an area of the brain, and how current is delivered, session length, or number of sessions may differ.

Currently, small, short-term studies show that tDCS may benefit people with:

• Depression: An analysis of 10 randomized trials found some participants were more likely to report fewer symptoms of depression, or remission of depression, after a course of tDCS treatment compared with sham treatment.
• Alzheimer’s disease: A review of seven studies found that tDCS lasting 20 to 40 minutes improved memory and other cognitive measures in people with mild to moderate Alzheimer’s disease.
• ADHD: One randomized trial of 64 adults with ADHD found improved attention after 30 minutes of tDCS daily for a month.

The FDA has not cleared tDCS for any health condition, and it is considered investigational. More research with positive results and reassuring safety data are needed before tDCS gets a thumbs-up from regulators.

That’s probably why some ads for tDCS note in fine print that it is not a medical device and is only for recreational use.

Does tDCS have downsides?

While the FDA assesses tDCS as safe for adults, there are downsides to consider. For example, treatment may cause itching, irritation, or small burns at the sites of the electrodes. Some users complain of fatigue or headache.

There are no large, long-term studies of tDCS, so overall safety is uncertain. Some experts believe at-home use raises many questions, such as how much of the brain beyond targeted areas is affected, what inconsistent approaches to tDCS use might do, and how long changes in the brain — intended or not — could last.

Very limited research has been done in children. So, the consequences for a child’s developing brain aren’t clear.

Finally, tDCS devices can be expensive (several hundred dollars or more), and generally are not covered by health insurance.

The bottom line

It’s not yet clear how tDCS should be used, or who is most likely to benefit from it. If you’re interested in pursuing tDCS, understand that there’s still a lot we don’t know.

If you’re more skeptical and risk-averse (like me), you may want to wait for more definitive research regarding its benefits and risks — and for now, stick with your morning coffee to clear your mind.

Follow me on Twitter @RobShmerling

About the Author

Robert H. Shmerling, MD,

Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

It used to be that doctors would automatically recommend treating all men with prostate cancer, even if their initial biopsies suggested the disease would grow slowly (or at all). But during the last several decades, the pendulum on treatment has swung the other way.

Doctors are now likely to advise active surveillance for low- to intermediate-risk cancers that may never turn deadly over the course of a man’s life. Active surveillance involves routine PSA checks, follow-up biopsies, and more recently, magnetic resonance imaging of a patient’s tumor. Treatment is initiated only when — or if — the disease shows signs of progression.

Recent evidence from Johns Hopkins University shows that the long-term risks of metastasis and death from low-grade prostate cancer among men on active surveillance averages just 0.1%. But doctors who care for such men also face a nagging question: which of their patients might have more aggressive cancer that should require closer monitoring? New findings published by the Johns Hopkins team in January provide useful insights.

The researchers’ approach

The researchers in this case zeroed in on the prognostic value of so-called perineural invasion, or PNI, on tumor biopsy samples. PNI simply means that cancer cells are moving into the perineural space between nerves in the prostate and their surrounding tissues. A finding of PNI raises red flags because the perineural space “provides a conduit by which tumor cells can potentially escape the prostate and grow elsewhere in the body,” says Dr. Christian Pavlovich, a urologic oncologist at Johns Hopkins who led the research.

Dr. Pavlovich’s team wanted to know if PNI detected on initial or follow-up biopsies would be associated with higher risks for cancer progression. So they analyzed long-term follow-up data from 1,969 men who had enrolled in an active surveillance research protocol at Johns Hopkins between 1995 and 2021. All the men were diagnosed initially with Grade Group 1 prostate cancer (the least risky form of the disease) and had undergone at least one follow-up biopsy since then.

What did the results show?

Among the 198 men with PNI, 44% of them (87 men in all) eventually progressed to Grade Group 2 prostate cancer, which is a more advanced form of the disease with an intermediate risk of further spread. Conversely, just 26% of the remaining 1,771 men without PNI (461 men) had progressed to Grade Group 2.

Pavlovich emphasizes that despite the new findings, PNI “does not make patients ineligible for active surveillance.” Importantly, the research showed that PNI was not associated with high-risk features, such as cancer in the lymph nodes of patients who wound up having surgery, or post-surgical elevations in PSA that show cancer still lurks in the body.

“What we’ve really shown here is that PNI puts men at a slightly higher risk of extraprostatic extension (cancer cells located just beyond the confines of the prostate),” Pavlovich says. “This is not necessarily a new finding. But PNI only occurs in about 10% of Grade Group 1 patients, and this is the boldest statement yet from the largest study conducted so far.” Pavlovich and his colleagues concluded that PNI provides an inexpensive and readily available indicator for identifying which men on active surveillance will benefit from more intensive monitoring protocols, including MRI and genetic tests.

Dr. Marc B. Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, agrees, while pointing out that PNI evaluations aren’t performed often enough. A PNI analysis of pathology specimens, he says, “along with emerging and sophisticated genetic testing of the tissue samples, may lead to more certainty in our recommendations to patients.”

About the Author

Charlie Schmidt, Editor, Harvard Medical School Annual Report on Prostate Diseases

Charlie Schmidt is an award-winning freelance science writer based in Portland, Maine. In addition to writing for Harvard Health Publishing, Charlie has written for Science magazine, the Journal of the National Cancer Institute, Environmental Health Perspectives, … See Full Bio View all posts by Charlie Schmidt

About the Reviewer

Marc B. Garnick, MD, Editor in Chief, Harvard Medical School Annual Report on Prostate Diseases; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Marc B. Garnick is an internationally renowned expert in medical oncology and urologic cancer. A clinical professor of medicine at Harvard Medical School, he also maintains an active clinical practice at Beth Israel Deaconess Medical … See Full Bio View all posts by Marc B. Garnick, MD