Is Transcranial Stimulation / Noninvasive brain stimulation Safe?
Transcranial direct current stimulation (TDCS) INVOLVES APPLYING A WEAK ELECTRICAL IMPULSE OR CURRENT TO THE SCALP, THEREBY ENHANCING OR DIMINISHING EXCITABILITY OF THE CEREBRAL CORTEX UNDERNEATH THE AREA OF STIMULATION. THERE IS A GROWING BODY OF SCIENTIFIC EVIDENCE THAT SUPPORTS ITS EFFECTIVENESS FOR USE IN CERTAIN NEUROLOGICAL AND PSYCHIATRIC CONDITIONS. Healthy individuals that use it also claim it ENHANCes COGNITION.
IS IT SAFE?
The thousands of articles published on transcranial stimulation over the past 20 years record no serious adverse effects. The only common side effects encountered included pain, skin redness, or tingling at the site of stimulation. Here is what we currently know about the safety of tDCS:
No formal safety guidelines. TDCS is NOT FDA approved for medical therapy of any kind.
The most common side effects reported are mild to moderate pain, skin redness or tingling near the site of stimulation.
Rare reports of mania or hypomania reported in patients with depression.
Should not be used in people with a history of seizures. A single seizure reported when tdcs was performed on a pediatric patient, although it is unclear whether the tDCS actually caused the seizure (as the patient had previously been diagnosed with a seizure disorder). Thus tDCS is still considered safe (Matsumoto and Ugawa, 2016).
Should not be used in persons with bioelectric devices such as cochlear implants, pacemakers, surgically implanted vagal nerve stimulators, deep-brain stimulators, or responsive neurostimulation devices.
As there is little data on its use in the pediatric population, references have recommended against its use on children.
ARE THERE ANY LONG-TERM SIDE EFFECTS?
Long Term Side Effects are unknown at this time.
Regarding both modalities, the long-term implications of use is currently unknown. Statements have been released by the International Federation of Clinical Neurophysiology (IFCN) and the Annals of Neurology expressing that there are potential risks associated with the use of tDCS that are time and stimulation dose dependent (IFCN, 2015; Monte-Silva et al, 2013). In other words, too long of desired stimulation can potentially lead to the opposite desired effects (IFCN, 2015; Monte-Silva et al, 2013).
Moreover, unplanned results may occur from the ‘build-up effects of multiple sessions or from influence on non-target areas’ (IFCN, 2015). In other words, placing electrodes in the wrong positions may lead to undesired/adverse structural changes over time. This is why it is important for people using tDCS to use it under the guidance of a trained professional.
ICFN Statement on Do-It-Yourself TDCS (December, 2015)
Matsumoto, H. Yokishikazu, U. Adverse events of tDCS and tACS: A review. Clinical Neurophysiology Practice p 19-25. (2017)
Monte-Silva, K., Kuo, M. F., Hessenthaler, S., Fresnoza, S., Liebetanz, D., Paulus, W., & Nitsche, M. A. (2013). Induction of late LTP-like plasticity in the human motor cortex by repeated non-invasive brain stimulation. Brain Stimul, 6(3), 424-432. doi:10.1016/j.brs.2012.04.01
Rossi, S., Hallett, M., Rossini, P. M., Pascual-Leone, A., & Safety of, T. M. S. C. G. (2009). Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research. Clin Neurophysiol, 120(12), 2008-2039. doi:10.1016/j.clinph.2009.08.01
Wexler A (2015). The practices of do-it-yourself brain stimulation: implications for ethical considerations and regulatory proposals. Journal of Medical Ethics 42, 211–215.
Wurzman, R., Hamilton, R. H., Pascual-Leone, A., & Fox, M. D. (2016). An open letter concerning do-it-yourself users of transcranial direct current stimulation. Ann Neurol, 80(1), 1-4. doi:10.1002/ana.2468
Disclaimer: Brain augmentation techniques such as those described in our website are not reviewed or approved by the FDA. The long-term consequences of tDCS are not well understood. However, we accept that use of these techniques occur, and we believe that offering responsible, harm-reduction, and scientifically-recognized information is imperative to keeping people informed. For that reason, the articles, guides, courses, and videos in our website are designed to expand knowledge of those who decide to pursue/research these techniques.
The information and devices displayed on this site are not intended to treat, cure, or prevent any medical disease, and the articles on this website are not medical advice. If a reader decides to purchase and use a tDCS device, it is his or her responsibility to use it correctly and safely.