In the world of psychology, deep brain stimulation (DBS) is a rising star for those in the medical field, attempting to find new and effective treatments for mental disorders. Now, new feats in engineering and technological innovations allow for notable leaps in the management of depression.
The National Institute of Mental Health calls depression and depressive illnesses “disorders of the brain.” With varied roots in environment, genetics, and elements of psychology, there has never been a one-size-fits-all method of treatment for depressive symptoms. However, DBS has produced primarily positive results with far fewer side effects than many pharmaceutical drugs, and it’s less time-consuming than endless therapy for those who have long struggled with depression and exhausted all other options.
At first glance, studies promoting DBS read like science fiction. Unlike electroconvulsive therapy (ECT), DBS targets specific areas of the brain, sending impulses aplenty through the brain via electrode stimulation. The stimulators are implanted in the brain, with a battery-operated generator placed in the chest. Like an outlet in a wall, this allows the body to be tuned into a new world of power-generated sensory input—and possibly an escape from longstanding depression, as well as post-traumatic stress disorder, obsessive compulsive disorder, and many other mental health issues.
Extremely thin, hollow tubes called cannulas are inserted for DBS electrodes, and connected wirelessly with a generator, placed inside the chest. These tubes are the method of transportation for specialized levels and frequencies of electrodes, set to activate various regions of the brain.
In 2012, an article entitled Treating Depression With Electrodes Inside the Brain, by Dr. Sanjay Gupta and Andy Segal of CNN, reported on the effective use of stimulator implants. Focusing on the case of Edi Guyton, who had struggled with depression for forty years before seeking experimental treatment half in the hopes that she might simply die in the process of finding a “cure,” Segal and Dr. Gupta describe the work of professionals like neurologist Helen Mayberg.
Though full FDA approval for implants is still pending, Mayberg said there have been many signs of progress for those undergoing DBS treatment. A small structure within the brain, commonly called Area 25, around the infralimbic cortex, is the target of deep brain stimulation. This area, associated with the release of stress hormones controlling fight or flight responses, is vital to the processing and managing of emotion-prompting stimuli. Area 25 is found to be more active in depressed patients, thus doctors hypothesize that DBS may essentially be pushing a mental reset button for the brain, perhaps serving to activate genes that had been dormant. Conversely, it could also act to suppress those components causing the psychological ruckus.
This past year, Charles Q Choi of LiveScience wrote of an improvement in this experimentation. Ada Poon, an electrical engineer and Stanford study author, explained how the testing process began on rodents, thus necessitating small and less cumbersome devices so that the observation could be accurate. Knowing that the wires would affect the behavior of the mice, engineers were insistent upon building implantable brain stimulators that were wireless, sleek and functional—and they succeeded.
At less than 3 millimeters in width, the stimulator is miniscule, and it works by using the energy of the host to gather and maintain energy. It is essentially a harvesting, recycling mind control device that puts a damper on overactive areas of the brain that cause (or at the very least, promote) depression.
Jim Morna of Draper Laboratory at Cambridge elaborated on the process, explaining, “We’re taking a wall of computers, basically, and putting it into something that would easily fit inside a box of Tic-Tac.” Morna is referring to the battery-operated generator inserted in the chest. But how does a battery and a stimulator treat a disorder that presents differently in various individuals, without a great degree of flexibility itself? Well, the device itself must be customized to any given person’s cognitive needs.
To accomplish this, scientists study “neural signatures,” or brain activity patterns, thus learning the proper settings for activation or suppression of particular regions. For instance, the amygdala can be overactive in PTSD. Therefore, activating the ventromedial prefrontal cortex—which would suppress it, may be just what the doctor orders.
Dr. Darin Dougherty of Massachusetts General Hospital, the director of neurotherapeutics, together with his co-leader of the Boston-located implant team, neurosurgeon Dr. Emad Eskander, currently head a military-funded study allowing researchers to track results and progress of patients with brain implants. With over $69 million backing the research, procedures, and charting, it’s no small step in medical and scientific exploration.
Like any job worth doing, half of the success lies in its foundation. Between research and prep work, the process of inserting electrode stimulators is no easy feat. Dr. Emery Brown of MIT compares the whole pre-implant brain-mapping to a smartphone’s GPS system, complete with the occasional need for rerouting.
“If I see that your brain activity is starting to move into that state indicative of you not feeling well…then I’m going to stimulate to correct that,” says Dr. Brown.
Once this process has been directed towards satisfactory results, the implant theoretically takes the wheel in attaining and holding positive results. But it’s no cakewalk from there. Depression is acknowledged to be a serious and complex mental health issue, and no one physical or psychological root has been established.
Scientific American published findings both in 2005 and 2012 hailing the strides taken in DBS but also cautioning overly-optimistic hopes for a magical “rewiring” of the brain. In other words, a cure for depression does not exist.
The brain can be reset, it seems, but not recreated. Impulse control is a multi-faceted rather than simplistic possibility. Ultimately, even technology must work with the ingredients available.