When it comes to issues of identity and authenticity in DBS, let patients have a voice
|Reconstruction of DBS electrode placement, image courtesy
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.
|Dr. Helen Mayberg
The initial DBS for depression study (Mayberg et al., 2005) was a major success and quickly made waves in psychiatry and the news media. To quote Dr. Mayberg, “the term ‘going viral’ didn’t exist in 2006 but it definitely went viral.” In an article entitled “A Depression Switch?”, David Dobbs writing for the New York Times Magazine profiled a patient, Deanna Cole-Benjamin, who was added to the initial study after several years of a devastating, profound depressive episode that had proven resistant to psychotherapy, drugs, and upwards of 100 electroconvulsive therapy sessions. Her experience with DBS, however, was extraordinary and she recounted it this way: “It was literally like a switch being turned on that had been held down for years…All of a sudden they hit the spot, and I feel so calm and so peaceful. It was overwhelming to be able to process emotion on somebody’s face. I’d been numb to that for so long.” Initially, Dr. Mayberg was dismayed by the article’s title, which indicated that this was a quick, almost miraculous fix rather than a long process that requires ongoing brain stimulation delivered long-term using the implanted device and active psychotherapy and retraining on the part of the patient to recover fully. But she recognized that these were, in fact, the patient’s words. Indeed, patients, Dr. Mayberg added, should have more a voice in the neuroethics literature.
|Location of area 25, image courtesy of Wikipedia
In a way, if the hypothesis that over-activity of area 25 is underlying MDD holds up to further testing then, in a simplistic sense, it fits nicely with the “back to your old self” notion. Conceptually speaking, this is not a method intended to overcome a negative with an overabundance of positives in other areas. Instead, the idea is to normalize the activity of a particularly powerful area where the activity somehow went a bit haywire. Researchers have in fact found that DBS of the nucleus accumbens, a key node of the so-called reward circuit, can elicit euphoric feelings (Synofzik, Schlaepfer, & Fins, 2012). Dr. Mayberg stressed that in her view, DBS of area 25 for MDD is different; that it restores more normal function and enables patients to get back to their lives (and rather than activating an area, she likens DBS in area 25 to taking off the brake). For this reason, Dr. Mayberg considers area 25 stimulation as more of a removal of inhibition that does not really create or activate a new identity, but circumvents the barrier to enable one to be their authentic self whoever that may be. But what is also missing from this explanation is how patients view who they are before and after stimulation and ultimately this is an empirical question, which is where Dr. Mayberg’s recent study on intraoperative self-assessment from patients come into play (Choi, Riva-Posse, Gross, & Mayberg, 2015).