Is tACS similar to "shock therapy"/ electroconvulsive therapy (ECT)?

​This is a question many people have. The short answer is "no." ECT is a FDA-cleared treatment for severe depression. ECT is administered under anesthesia and uses much stronger electrical currents than tACS. The purpose of ECT is to elicit brain activities that looks like an epileptic seizure. Scientists are still working on figuring out why ECT helps some patients with severe depression. Some believe it acts as a "reset" of brain activity, others have found that ECT may trigger the brain to grow new neurons and connections between neurons. Some patients report significant side-effects such as impaired memory after ECT. In contrast, tACS uses very weak electricity, does not require anesthesia, and has been safely applied to thousands of research participants. Although it is not yet fully understood how tACS changes electrical signals in the brain, it is clear that it does not "reset" brain activity and that it does not generate unusual activity patterns such as seizures. In fact, the biggest riddle for scientists who study tACS is how such a small amount of electrical current can change brain activity at all. Of note, tACS is currently studied as a potential treatment for illnesses such as depression, however more studies are needed and tACS is, for that reason, not FDA cleared. Thus another major difference is that ECT has been shown to help patients with depression, whereas tACS has not yet cleared that hurdle.

My loved one has a brain illness. Would tACS help?

We understand the burden, worry, and stress for the patient and their loved ones caused by an illness of the brain. Unfortunately, the most direct answer to this question is "we do not know yet." This is of course a very frustrating answer. Clinical trials of tACS in psychiatry have only begun few years ago and the first results were published in 2019 (initial pilot studies in depression, schizophrenia, chronic pain). The development of tACS as a treatment is based on a disease model that a pathological change in brain rhythms causes symptoms. This is notion is not (yet) supported by all scientists. More research is urgently needed.

How can I help to advance the development of tACS as a treatment?

Thank you for asking this question. There are numerous ways how you can support research in general and research of tACS in particular. First, you can become a science advocate by spreading the news about science and its value for the advancement of humanity. Second, you can consider participating in a tACS research study. There are numerous studies that investigate how tACS works in both patients and in healthy people. Given the outstanding safety profile of tACS, we encourage you to consider participating as a research subject. Of course, there are numerous things to consider, including the specifics of a given study that the research personnel will be more than happy to explain and discuss. Third, if you are able and inclined to do so, you can explore financially supporting tACS research.

If the weak electricity of tACS changes brain activity, power lines and cell phones must be dangerous, right?

Many scientists have/had that question, as well. The short answer is "no." The electric field of power lines is much lower than the lowest electric field that may change brain activity. Cell phones use very different signals that cannot be directly compared to tACS. There are patients who report medical symptoms in response to the exposure to electric fields. This is a poorly understood illness and the suffering of these patients is real. However, what we know about tACS cannot explain these symptoms.

Is tACS the same as cortical electrical stimulation (CES), which is marketed as FDA cleared for several indications, including depression and pain?

CES and tACS have one thing in common: both use weak electric current to change electrical activity patterns in the brain. However, this is where the similarities end. The biological mechanism of CES is unclear and mostly unstudied. One theory is that CES stimulates the vagus nerve, one of the major "data highways" that connect the body to the brain. Of note, not understanding how something works at level of biology does not mean that it cannot relieve symptoms. The number of high-quality clinical trials of CES appears to be rather limited. In contrast, tACS appears to directly strengthen brain rhythms by interacting with activity patterns generated by networks of brain cells. However, it is unknown if tACS can treat any illness. Ongoing and future clinical trials following the most stringent scientific standards will help us answer this question. One other distinction to keep in mind is that several CES device companies are pursuing marketing campaigns directly targeting patients. As for any other medical decision, we recommend to discuss all possible treatment options with a trusted and expert healthcare provider.

I have heard that tACS does not work because the amount of current is very weak and is not enough to change brain activity. Is this true?

Any new research field is going through ups and downs, especially at the beginning. Often, something new starts of with lots of excitement, leading to quite a hype. In response, with some delay, excitement is often diminished by studies that seemingly claim the opposite. Unfortunately, the most likely outcome is a split in the field with acrimonious debates and accusations that could make great daytime TV but definitely lead to poor science. In reality, things are more complex and nuanced. But who today has time for details and nuances...
In the case of tACS, the originally hype was dampened by studies that showed that weak electric fields cannot turn on and off neurons (in technical terms: trigger an action potential) at will. This was misunderstood or perhaps on purpose sold as "tACS does not work." In reality, nobody had ever claimed that tACS effectively causes neural activity. Rather, there is quite convincing evidence that tACS adjusts and improves the timing of neuronal activity. As a result, synchronization of electrical signals in the brain is enhanced, which may ultimately be of therapeutic benefit for illnesses such as depression and schizophrenia.

Where can I buy a tACS device to treat my depression/pain/schizophrenia/etc.?

It is important to understand that tACS is not yet FDA cleared for any indication and more research is needed to understand if and how tACS treats any illness. Thus, there are no legitimate tACS devices that can be purchased by people who are not researchers. You may find websites that sell something that sounds like a tACS device. We recommend not to take that route since these devices are of unknown safety. Together with the fact that we do not know if and how tACS treats brain illnesses, we consider the risk of at-home use of such devices outside of established research studies too risky. However, we encourage you to inquire about clinical trials that investigate tACS. Perhaps there is a study that you are eligible to participate in.
Disclaimer: This site is designed to provide general information about tACS. Nothing should be misunderstood as medical advice. This site does not provide medical advice. tACS is not FDA cleared for any treatment and is only used in research studies under stringent oversight of the relevant regulatory bodies.