Left to Their Own Devices: Issues in the Informed Consent Process for Transcranial Direct Current Stimulation

There is a growing trend for patients to obtain and use tDCS devices without the interposition of a psychiatrist filling the traditional medical-legal role of learned intermediary. The authors explore various issues.

Emerging nonpharmacological somatic modalities aimed at ameliorating psychiatric illnesses, such as ECT, deep brain stimulation (DBS), and transcranial magnetic stimulation (TMS), were initially considered dangerous, invasive treatments of last resort.1,2 Yet accumulating evidence and continued advancements in neuromodulation have demonstrated their potential to quickly relieve, or even reverse, the symptoms of certain mental illnesses -most notably depression.3

While there are well-documented risks and adverse effects with ECT, DBS, and TMS, they have an overall favorable safety profile that is comparable, or even superior to, many standard pharmacotherapies.4 This track record of safety and efficacy has brought about an encouraging shift in professional judgment and public opinion regarding these modalities.

With any new discovery in science and medicine, especially those in fields such as psychiatry where new treatments for devastating diseases are urgently sought, there is always an ethical concern for the adequacy of the informed consent process. In this article, we suggest that a coalescence of social, cultural, legal, economic, and technical forces has shifted the power of scientific information in dramatic ways, cutting out the clinician while leaving consumers to their own devices when it comes to neuromodulation.

With its legal grounding and associated regulatory enforcement potential, informed consent can be a mechanism that safeguards patients from coercive forces to maximize autonomous treatment decisions. With the exponential pace of technological development in neurostimulation techniques, even the most up-to-date and conscientious psychiatrist may face unrecognized barriers, which can thwart his or her attempts to conduct a high-quality informed consent discussion about these technologies. Among the most insidious of these barriers are the American desire for a quick, inexpensive, and relatively painless cure, and a permissive regulatory environment in which curative or restorative treatments can be directly marketed to patients for a price.

The ubiquity of information available about neurostimulation in the digital age and the often-altruistic tendency to share and recirculate information -regardless of its veracity -has only exacerbated this concern, creating a more broadly informed, but not necessarily better informed, society in search of medical miracles. This poses a further complexity as patients may adopt an overly optimistic, possibly myopic view of nascent biomedical technologies. If clinicians are unaware of just how easy it is for patients to obtain -or even manufacture -medical devices intended for self-neurostimulation, they will not have an opportunity to provide patients with a balanced, evidence-based estimation of the therapies as would occur in the usual course of clinical care.

Transcranial direct current stimulation (tDCS)

While these issues are pertinent to other forms of neuromodulation, this article focuses on transcranial direct current stimulation (tDCS). We chose this modality because there is a growing trend for patients to obtain and utilize tDCS devices without the interposition of a psychiatrist filling his traditional medical-legal role of learned intermediary. tDCS devices stimulate the brain via electrodes that are applied directly to the scalp. Scientists have long suspected that this kind of neurostimulation can assuage anxiety and depression while also enhancing cognition and overall performance. For example, a peer-reviewed paper written by 2 prominent neurophysiologists nearly 2 decades ago found that a low-intensity electric current passed through the motor cortex enhanced performance on various motor tasks.5 Despite such continued exciting findings, researchers warn that transcranial stimulation extends well beyond the regions beneath the electrodes, and can affect unintended areas of the brain. Therefore, while the term “deep brain stimulation” has been reserved for a specific neurosurgery, tDCS may necessitate a rethinking and redefining of depth in what has heretofore been thought of as a noninvasive technique.6

The marketing of tDCS to consumers synergizes 2 other cultural trends: the explosion of information available to patients and the over-valuation of neuroimaging. Studies that promote neuroscientific breakthroughs are no longer reserved for biomedical journals but are increasingly published electronically in non-professional or quasi-professional venues.7 It will come as no surprise that a cursory online search of neurostimulation yields results that are scientifically incorrect, reductive, or misleading by omission.

Many of these websites contain impressive colorful brain scans purporting to demonstrate dramatic clinical improvement with tDCS for serious psychiatric disorders such as depression and ADHD.8 An online article aimed at describing the unknown harms may unintentionally convey misleading information merely through its choice of language. Even more balanced media coverage of tDCS may leave patients, especially those with low scientific literacy and refractory illness, with unrealistic expectations in which benefits are amplified and risks attenuated.

FDA approval and exceptions

The publication of promising findings that enter popular discourse may correlate with the increase in direct-to-consumer marketing of myriad neurostimulation devices, some of which boast FDA compliance certification. For example, Caputron Medical (Caputron) describes itself as “the leading worldwide distributor of home, clinical and research neurostimulation technology, such as tDCS, TMS, CES and EEG . . . committed to improving the field through the development and distribution of novel therapeutics and supporting innovative research devices.”9 Relying on the product description alone, however, may not sufficiently convey critical treatment information that a consumer who lacks administrative law expertise could easily overlook, but about which a clinician would have likely educated the patient during an individually tailored, thorough informed-consent process.

While many cranial electrotherapy stimulation CES products are appealing in their optimism, mental illnesses often require more than “a little help.”

Although technically and legally accurate, product descriptions that use simple language to convey complex phenomena risk deception via reduction. For example, the popular product mindGear is described as “the gentle, FDA cleared drug free CES [cranial electrotherapy stimulator] treatment for depression, anxiety, and insomnia” that, “based on decades of research at the nation’s [sic] best medical centers and with thousands of satisfied users, provides you fast-acting relief, without the complications of drugs, in the privacy of your home or work. mindGear applies a gentle energy to your brain, allowing you to help yourself feel relief. Sometimes all you need is a little help. mindGear is there when you need it.”10

While many cranial electrotherapy stimulation (CES) products are appealing in their optimism, mental illnesses often require more than “a little help.” Downplaying the severity of any illness or creating the conditions in which one is reasonably led to believe that suffering can be overcome by a machine that poses little to no risk may delay obtaining professional medical attention. Moreover, consumers who are unaware of the intricacies of FDA regulations may conflate FDA 510(k) clearance with FDA approval in the mindGear product description. 510(k) clearance is a significantly less burdensome process that demonstrates equivalence to existing devices compared with the rigorous administrative procedure that demands evidence of efficacy and safety. The FDA’s 510(k) scheme allows CES device developers to avoid the premarket approval process if they can demonstrate substantial equivalence to a predicate device.

In bringing so many TMS, CES, DBS, and tDCS devices to the market, manufacturers say they “are able to help bridge the gap between research and consumer.”9 We argue that the gap being bridged here is not an intentional withholding of effective treatments; rather, the gap creates necessary distinctions, division of roles, and expectations between a fully informed patient, a fully informed human research subject, and a fully informed consumer.


Regulatory oversight and neuroenhancement

Easily accessible information about tDCS and similar devices, combined with thousands of popular articles flaunting myriad benefits, has spawned a growing online do-it-yourself (DIY) tDCS community where anonymous users post about their self-experimentation on a host of mental illnesses, including depression, OCD, and bipolar disorder. As Wexler11 documents, isolated mentions of DIY tDCS became an entire online community during 2011 and 2012, thanks to the ease of venues like REDDIT and subsequent user-generated blogs dedicated exclusively to self-stimulation technology and administrative techniques, such as optimizing electrode placement, dosage, and frequency. A little creative Googling and you, too, can learn how to build your own tDCS device in less than 10 minutes, thanks to a YouTube tutorial that manages to keep the cost within a $10 budget.

Because tDCS devices can be purchased from the Internet and manufactured with simple tools and basic electronic parts at home, such as a standard 9-volt battery and dish sponges, their use has grown exponentially. Techniques are refined, and information is distributed and redistributed among anonymous users.

It is easy to see the appeal. Psychiatry is a profession criticized -albeit often unfairly -for using coercion. tDCS offers individuals the opportunity to freely exercise their autonomous medical decision-making authority by not only choosing but also making and administering state-of-the-art mental health treatment. Individuals who wish to avoid the cost and stigmatization of psychiatric care and the ostensible risks of pharmacotherapies -also hyped in the media -are attracted to neuromodulation alternatives for bona fide psychiatric disorders and increasingly for purposes of neuroenhancement. tDCS offers a near-perfect option for the high-technology version of cognitive self-improvement.

Voarino and colleagues12 explore ethical issues of informed consent and privacy and safety that arise when tDCS is used for the non–FDA-approved indication of memory enhancement. The inevitability of expanded use of tDCS for neuro- enhancement has led many legal analysts to advocate for the devices to be brought under the FDA’s more stringent regulatory framework so that there is at least some amelioration of the risks the devices present. These analysts point out the neuroethics dictum that uses of tDCS for enhancement today will soon become the therapeutic uses of tomorrow -and hence from a legal standpoint should be classified similarly.13

Circumventing informed consent

By circumventing the traditional process of informed consent intended to educate, empower, and protect the patient, tDCS presents complex ethical concerns that warrant further attention. As discussed, this makes it difficult if not impossible for the psychiatrist to engage in the shared decision-making model that is the preferred ethical standard of practice.14 What demands urgent attention, however, is that absent such a consent discussion, patients may either misunderstand or fail to fully appreciate the very real risks of these DIY treatments. For example, in patients with bipolar disorder, tDCS may give rise to hypomanic episodes, which underscores the need for careful psychiatric assessment to rule out previous episodes suggestive of bipolar disorder before using tDCS to treat presumed unipolar depression.3 Steenbergen and colleagues15 provide a good example of a commercially available tDCS system purported to improve cognition that actually impairs it.

This unprecedented form of self-help has drastically undercut not only the informed consent process but also the professional requirements for conducting the fundamentals of a psychiatric evaluation. tDCS may be administered without a mental health professional ever taking a psychiatric and medical history, performing relevant physical and neurological evaluations, ordering and reviewing laboratory tests, or obtaining any of the other traditional inputs to the formulation of a differential diagnosis and individualized treatment plan.16

Similarly, the careful, consistent monitoring of target symptoms and adverse effects, formation of a therapeutic alliance, and empathic exploration of the life circumstances of the patient -all integral to sound clinical practice -are, pardon the pun, short-circuited. Psychiatric illness is deconstructed so that only the brain exists and carries significance. The overall health of the body and the psychosocial context of the illness can be eschewed when promising and powerful treatment is co-opted, operating outside the bounds of professional guidance, oversight, and accountability.


Psychiatrists have a legal and ethical duty to ensure that a fully transparent consent process takes place, and a patient’s decision regarding treatment is freely made. However, when treatment occurs outside the clinical setting and manufacturers deftly dodge regulatory safeguards, those who suffer from the devastating effects of mental illness are literally left to their own devices to find relief. With affordable mental health care in a state of political jeopardy, the financial cost of DIY tDCS may seem small, but the risks of neurostimulation absent adequate clinical oversight render their true cost unquantifiable. Let us hope that in this brave new era of “electroceuticals,” the fastest-growing area in the treatment of neurological and psychiatric disorders, it is the patient who manages to profit.17


Dr. Esplin is Assistant Professor, Department of Humanities in Medicine, Texas A&M University Health Science Center, Bryan, TX. Dr. Geppert is Professor of Psychiatry and Director of Ethics Education, University of New Mexico School of Medicine, and Chief, Consultation Psychiatry and Ethics, New Mexico VA Health Care System, Albuquerque, NM.

The authors report no conflicts of interest concerning the subject matter of this article.


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17. Caputron Medical Announces FDA Cleared mindGear Treatment for Depression, Insomnia and Anxiety. http://www.businesswire.com/news/home/20151201005665/en/Caputron-Medical-Announces-FDA-Cleared-mindGear-Treatment. Accessed September 6, 2017.