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Deep Brain Stimulation: From Parkinson treatment to personality enhancement?

  • Posted On: 3rd June 2014

By Frederic Gilbert

In recent years, Deep Brain Stimulation (DBS) treatments have attracted great interest in the medical community, not only for their effectiveness, but also for their expanded, potential future applications. With these great hopes come various accompanying ethical challenges.

DBS is a psychosurgical invasive intervention commonly used to treat various symptoms of neurodegenerative diseases. For instance, the most common application of DBS treatments has targeted Parkinson’s symptoms such as tremor, rigidity, stiffness, slowed movement, or even walking problems. The technique consists of implanting a battery-operated neuromedical device which delivers an electrical stimulation to a specific area of the patient’s brain. However, due to its invasive nature, in order to qualify for DBS treatment, patients must be in an advanced phases of a neurodegenerative disease and have demonstrated resistance to pharmacological treatment. However, in the future, developments in medical nanotechnologies hold the potential to render the DBS procedure less invasive, thereby expanding the safety and range of applications for these technologies.

Indeed, besides being used to diminish Parkinson’s symptoms, DBS procedures have also been used to treat severe depression, obsessive-compulsive disorder, obesity, epilepsy and Tourette syndrome, among countless other applications. Moreover, in some cases, DBS has been found to be correlated with cognitive (e.g. memory) and mood enhancements (e.g. decrease in major depressive tendencies). These discoveries have sparked great interest. Given these neuroscientific findings, one could ask what if one day, DBS were not strictly reserved for treating patients with neurodegenerative diseases? What if its applications are expanded for cognitive and personality enhancement in healthy subjects? Given this possible extension of the uses of DBS, it behoves us to ask: Is there something intrinsically unethical about using DBS for enhancement purposes with perfectly healthy, fully informed, free, consenting subjects? Is there a risk that these novel technologies may even transform the personal identity, or even the “true nature” of these subjects?

If there is a genuine ethical problem associated with the use of DBS for enhancement of cognitive capacities in healthy subjects, it is not on account of the risks of transformation of personal identity. Indeed, it would be a philosophical blunder to believe that the risks of upsetting personal identity through DBS are categorically different from that which might be achieved through pharmacological enhancements. Concerns that technology may threaten personal integrity are sometimes overstated. Comparatively speaking, a glance at how religion or cultural identity can permanently affect personality tells us that DBS may not be more damaging to the integrity of one’s person than, say, unconscious social pressure in a healthy individual’s life.

Given that every type of medical treatment aims to enhance or improve a patient’s quality of living, it follows that every treatment is a form of enhancement. To speak about the distinction between treatments versus enhancement is neither necessary nor helpful in order to find the appropriate ethical framework for the use of DBS in healthy, informed and consenting subjects. DBS will only be ethically approved for healthy subjects if these subjects make unsolicited and informed decisions; only this approach to conditions for access to DBS will ensure ethical approval for the field. If this procedure were to be made available to a larger population and thus become an elective procedure, the DBS field should avoid being inspired by pure mercantile profit; it should avoid the less-than-noble model of the field of plastic surgery, where recently disorders of what is termed “plastic surgery addiction” have been observed, thus creating a new pathology.

On the other hand, the invasive nature of DBS procedures exacerbates the bona fide concerns of safety as compared to non-invasive pharmacological interventions, such as selective serotonin reuptake inhibitor drugs or beta-receptor blockers. Since pharmacological intake implies less severe risks and adverse complications, both in the short and long term, it stands to reason that a non-invasive method is undeniably preferable to surgical interventions for enhancement. Although the application of DBS does not seem to raise novel ethical problems, significant ethical concerns are nonetheless at stake. Most notably, are the age old concerns of safety tied to the very invasive nature of the involved procedures. Besides the technical difficulties involved in making risk assessments which try to project the likelihood and extent of harms that could result for patients, there are also ethical difficulties to face. These include questions such as: 1. Under what circumstances should patients be rightfully offered DBS? 2. What level of prospective benefit could justify such dangerous, invasive treatments? 3. Are patients who might be interested in DBS desperate, and in this state are they likely to succumb to what is termed the “therapeutic misconception” – the misconception that a treatment holds real promise of either a cure or substantial therapeutic benefit when in fact what is on offer is not proven, but simply a tool being tested as a function of research? 4. How should DBS be regulated in such a way to assure first and foremost patient safety, without stopping the research altogether in this field? These questions require detailed ethical analysis and should receive answers based on the bioethical principles of beneficence— promoting well-being or benefit— and Non-maleficence—refraining from harm. These questions must be thought through and given serious ethical attention, before applications for DBS can be approved for use in healthy human subjects.

Concerning the principle of beneficence, it must be proven that DBS, in fact, enhances mood and cognitive abilities in healthy subjects; additionally, DBS has to be proven more effective than pharmacological measures. Concerning the principle of non-maleficence, severe short- and long-term effects have to be eradicated on both a physical and psychological level before DBS can be considered a viable option for healthy subjects. Yet, to meet the ethical requirements of beneficence and non-maleficence, DBS must prove itself, and part of doing so means that it must pass scientific muster. At this point, assurances of the safety and efficacy of DBS are not borne out in the literature. In this regard, current reporting on DBS is particularly vulnerable to researcher/investigator bias because of an excessive reliance on single-patient case reports. Although the risk selective publishing poses is by no means unique to DBS, it is essential for safety and efficacy to be proven, and for this higher powered studies will be needed. Ethical patient selection for such studies will of course be a challenge. Alternatively, without higher powered studies, investigator bias and wrongful suasion may drive development of this research.

Acknowledgement: Canadian Institutes of Health Research; MOP 77670, Therapeutic Hopes and ethical concerns: Clinical research in the neurosciences and NNF 80045, States of Mind: Emerging Issues in Neuroethics.


Frederic Gilbert, Ph.D.
Dalhousie University

Brenda Wiederhold About Brenda Wiederhold
President of Virtual Reality Medical Institute (VRMI) in Brussels, Belgium. Executive VP Virtual Reality Medical Center (VRMC), based in San Diego and Los Angeles, California. CEO of Interactive Media Institute a 501c3 non-profit Clinical Instructor in Department of Psychiatry at UCSD Founder of CyberPsychology, CyberTherapy, & Social Networking Conference Visiting Professor at Catholic University Milan.

Written by Brenda Wiederhold

President of Virtual Reality Medical Institute (VRMI) in Brussels, Belgium. Executive VP Virtual Reality Medical Center (VRMC), based in San Diego and Los Angeles, California. CEO of Interactive Media Institute a 501c3 non-profit Clinical Instructor in Department of Psychiatry at UCSD Founder of CyberPsychology, CyberTherapy, & Social Networking Conference Visiting Professor at Catholic University Milan.