By Ryan Purcell
Deep brain stimulation (DBS) is an extraordinarily popular topic in neuroethics. In fact, you could fill a book with all of the articles written on the subject just in AJOB Neuroscience alone (and the editors have considered doing this!). A special issue on the topic in AJOBN can be found here. Among the most widely discussed neuroethical issues in the DBS arena are concerns over the effects on patient identity and authenticity. But perhaps one perspective that has not been fully represented in the academic literature is that of the patients for whom this is actually their last hope to find a way out of a profound, debilitating and often years-long episode of depression. At February’s Neuroethics and Neuroscience in the News journal club, Dr. Helen Mayberg spoke passionately about the approach that led her team to attempt DBS for major depressive disorder (MDD), the ensuing media response, and how that has affected her ongoing work to improve the technique, better understand the etiology of MDD, and allow patients to get back to their lives.
|Reconstruction of DBS electrode placement, image courtesy|
The DBS for depression story goes back more than a decade and began in Toronto. Dr. Mayberg’s group consistently found cingulate area 25 to be differentially active in mood studies; it was tonically active in depressed patients and became transiently activated when healthy subjects were saddened while in the PET scanner (Mayberg, 1997). The idea was put forward that if the activity of this area could be reduced, perhaps it may lift some patients who had exhausted all other options out of the depths of the most debilitating degrees of depression. By this time, deep brain stimulation of the basal ganglia had become a mainstream treatment to calm tremors resulting from some motor disorders, particularly those resulting from Parkinson’s Disease.
|Dr. Helen Mayberg|
Neuroethicists have written at length about the potential effects of DBS on patient identity (Baylis, 2013), what it means for authenticity, and also ideas such as alienation (Kraemer, 2013). These are important issues as Parkinson’s patients undergoing DBS for motor symptoms, for example, have on occasion had serious negative post-operative side effects including mania and suicidal ideation (Kraemer, 2013). Perhaps the most central questions to neuroethicists are 1) is the device infringing on or altering patient autonomy and 2) is the patient’s identity or authentic self fundamentally changed by the so-called brain pacemaker. However, hearing Dr. Mayberg describe patients who have been completely debilitated by the disease, who can no longer care for themselves or others and think of little other than suicide, ethical concerns about whether a potential treatment might compromise the patient’s authenticity seem absurd. If your authentic self essentially cannot function any longer then is there any other option but to alter it? Still, post-operatively some patients describe an anxiety or fear that the efficacy of the stimulation will erode over time and that at any moment, the disease that, in Deanna’s case, came on without warning, could re-emerge. Dr. Mayberg, though, contends that successful DBS procedures return patients to who they really are, that identity could be better defined as “who are you without depression.” This can be difficult to ascertain for the researchers, however, because their first impression of the patient is always in a profoundly depressed state, and they can only see that pre-depression identity through the eyes of their family and friends.
|Location of area 25, image courtesy of Wikipedia|
The neuroethical discussions over how to understand the many applications of DBS and its consequences for patients will continue and, it now seems, so will the medical and scientific debates over the effectiveness of the procedure. The multi-site BROADEN clinical trial was halted and there has been some degree of blowback on other blogs criticizing the early enthusiasm surrounding DBS for MDD. The potential physical and nonphysical harms of such an intervention, the critics argue, are not worth the risks given the absence of a consistent benefit. But perhaps now is the best time, as researchers continue to push forward in the pursuit of understanding MDD’s underlying mechanisms and how DBS might help patients with MDD, to also reconsider the approaches to evaluating patients’ perspectives and views on the value and risks of the intervention.
Baylis, F. (2013). “I am who i am”: On the perceived threats to personal identity from deep brain stimulation. Neuroethics, 6(3), 513–526. http://doi.org/10.1007/s12152-011-9137-1
Choi, K. S., Riva-Posse, P., Gross, R. E., & Mayberg, H. S. (2015). Mapping the “Depression Switch” During Intraoperative Testing of Subcallosal Cingulate Deep Brain Stimulation. JAMA Neurology, 72(11), 1–9. http://doi.org/10.1001/jamaneurol.2015.2564
Kraemer, F. (2013). Authenticity or autonomy? When deep brain stimulation causes a dilemma. Journal of Medical Ethics, 39(12), 757–60. http://doi.org/10.1136/medethics-2011-100427
Mayberg, H. S. (1997). Limbic-cortical dysregulation: a proposed model of depression. The Journal of Neuropsychiatry and Clinical Neurosciences, 9(3), 471–81. http://doi.org/10.1176/jnp.9.3.471
Mayberg, H. S., Lozano, A. M., Voon, V., McNeely, H. E., Seminowicz, D., Hamani, C., … Kennedy, S. H. (2005). Deep Brain Stimulation for Treatment-Resistant Depression. Neuron, 45(5), 651–660. http://doi.org/10.1016/j.neuron.2005.02.014
Synofzik, M., Schlaepfer, T. E., & Fins, J. J. (2012). How Happy Is Too Happy? Euphoria, Neuroethics, and Deep Brain Stimulation of the Nucleus Accumbens. AJOB Neuroscience, 3(May 2012), 30–36. http://doi.org/10.1080/21507740.2011.635633
Want to cite this post?
Purcell, R. (2016). When it comes to issues of identity and authenticity in DBS, let patients have a voice. The Neuroethics Blog. Retrieved on , from http://www.theneuroethicsblog.com/2016/03/when-it-comes-to-issues-of-identity-and.html