In a growing trend, some people are using at-home devices that initiate transcranial direct current stimulation (tDCS)—also known as "brain zapping"—in order to reap a range of purported neural and psychological benefits.
Patients are using these devices in hopes of improving mood, memory, creativity, and learning, and also to combat symptoms associated with COVID-19, ADHD, and Alzheimer's disease.
Experts say there are risks involved in using tDCS, and as the devices are not yet approved by the FDA to treat specific conditions, they should be considered a “recreational” device as opposed to a medical device.
Transcranial direct current stimulation (tDCS) devices, which apply low-intensity direct current to the scalp, are becoming popular at-home tools used to improve mental clarity while combating symptoms associated with COVID-19, ADHD, and even Alzheimer's disease.
Research into tDCS has picked up steam in recent decades, leading many to want to take advantage of the purported health benefits. But tDCS is not without its risks. If your patients are interested in so-called “brain zapping,” it’s important to discuss with them both the potential benefits and risks.
A brief history of tDCS
The use of tDCS has a long history, with early studies dating back to the early 19th century.
The use of electrical stimulation for therapeutic purposes has roots in the field of electrotherapy, which has been explored for various medical conditions.
However, the specific technique of tDCS, involving the application of low-intensity direct current to the scalp, gained prominence as a non-invasive brain stimulation method in recent decades. Its potential benefits were first identified in an influential 2000 paper that demonstrated the modulatory effects of tDCS on cortical excitability in humans, sparking further interest and research in the field. Since then, tDCS has been the subject of numerous studies exploring its effects on various cognitive, motor, and neuropsychiatric conditions. Its potential as a research tool and therapeutic approach continues to be investigated and refined, with ongoing advancements in understanding the underlying mechanisms and optimizing stimulation protocols.
All of this “buzz” may be leading patients to purchase devices that can offer tDCS—or “brain zapping”—from the comfort of their own home.
A deeper dive into the mechanics of brain zapping
Transcranial direct current stimulation works by applying a low-intensity direct current to specific areas of the scalp, which modulates cortical excitability and activity in the brain, according to an article in Restorative Neurology and Neuroscience.
The process involves the application of a weak electrical current, typically ranging from 1 to 2 milliamperes (mA). This current flows between two or more electrodes placed on the scalp. The electrodes used in tDCS consist of an anode (positive electrode) and a cathode (negative electrode). The anode is usually positioned over the target region of the brain, while the cathode serves as the reference point.
When the electrical current is applied, it creates a polarization effect. The anode increases the excitability of neurons in the underlying brain area, while the cathode decreases their excitability.
This polarization influences the resting membrane potential of neurons, which is the electrical charge difference between the inside and outside of the neuron. Anodal stimulation increases the neuronal membrane potential, making the neurons more likely to fire, while cathodal stimulation decreases the membrane potential, making the neurons less likely to fire.
By modulating the resting membrane potential, according to the Restorative Neurology and Neuroscience authors, tDCS can affect the firing rates and excitability of neurons in the targeted brain region. This modulation leads to changes in neural activity and communication within the brain networks.
It is important to note that the effects of tDCS are not limited to the stimulated area. The changes in excitability and neural activity can spread to interconnected brain regions, potentially influencing cognitive processes, mood regulation, and other brain functions.
The benefits of this method, as cited by the authors of an article published by JSTOR Daily, include improvements in mood, increased creativity, memory enhancement, and accelerated learning. These benefits are purportedly available to patients at home, upon purchase of any of various tDCS devices, available online for a couple hundred dollars or less.
The devices are compact, handheld machines featuring two electrical leads capped with sponges. When ready to use, users dip the sponges into a saline solution and apply them to the head.
These devices are being used in the hope of achieving a bit of a “boost.” For some patients, this provides them with relief from symptoms associated with depression, ADHD, long COVID, and other conditions, according to an article from Harvard Health Publishing.
Know the risks
Most tDCS devices are not yet FDA approved to treat specific conditions. The FDA has cleared tDCS devices for the treatment of major depressive disorder in adult patients who have failed to respond to antidepressant medications. (Note: FDA clearance means that the device has demonstrated safety and effectiveness for a specific intended use, while approval generally refers to broader recognition of a treatment as safe and effective.)
The specific tDCS device approved for this indication is the Soterix Medical 1x1 tDCS System.
Nevertheless, do-it-yourself tDCS may entail a series of health-related risks.
The article in JSTOR Daily notes that tDCS devices sold for at-home use may produce unintended effects.
“One model tested in a university lab actually impaired memory,” the authors wrote. “Incorrect use and placement of the electrodes can also produce unreliable results. All this could diminish any good effects from tDCS.”
On the other hand, as the authors of an article in Frontiers in Neuroscience note: “There are no reported indications of any serious adverse effects with the use of 1–2 mA tDCS. However, mild temporary side effects may occur, such as headache, a cutaneous sensation at the stimulation sites, moderate fatigue, redness of the skin under the electrode pad, difficulty concentrating, acute mood changes and nausea.”
Effects on different patient populations
In particular, the side effects that tDCS may induce in children are largely unclear.
According to a study published by Frontiers in Human Neuroscience, the “degree of excitability” that tDCS may create in the brains of children is difficult to predict.
As a result, researchers can’t rule out the potential for this treatment to induce seizures in young patients—though they believe it to be unlikely among the majority.
All things considered, tDCS could be a tool that patients can use to enhance memory, boost mood, and fight symptoms of depression and other mental health conditions. Research, however, has yet to confirm the efficacy of at-home tDCS use. For now, you may keep patients informed about the potential benefits—and risks—associated with it.
What this means for you
The use of tDCS to help patients establish brain-behavior relationships has been popularized in the past decade. Some patients now use devices that offer tDCS from the comfort of their home. You may inform patients who are interested in do-it-yourself tDCS about potential side effects, some of which include headache, cutaneous sensations, difficulty concentrating, changes in mood, and nausea. Patients should be informed that the devices being marketed for their ability to enhance brain performance with tDCS have yet to gain FDA clearance.