Treatments for depression have come a long way over the last two centuries with remedies that have included plant-based and pharmacological preparations, but scientists and professionals find some depressive disorders continue to resist treatment. However, if enough successful clinical trials take place, the Food and Drug Administration in the U.S. and Canada (FDA) may soon be able to approve a more physically invasive treatment that has been showing tremendous promise for severe depression sufferers.
The hopeful treatment is called deep brain stimulation (DBS) and is an experiment in brain surgery. In a 2009 article for the Monitor, a publication of the American Psychological Association, staff writer Michael Price explained that DBS was not originally identified as a treatment for depression. “DBS was first recognized as a treatment for motor symptoms of Parkinson's disease,” he wrote, “but now researchers are harnessing the procedure to normalize misfiring brain circuits in people whose depression won't respond to behavioral therapy or medicine.”
In fact, in June 2015 and February 2016, the U.S. FDA and Canadian FDA, respectively, approved the use of deep brain stimulation devices to help reduce the symptoms of Parkinson’s disease and essential tremor. Experiments in DBS for chronic depression began back in 2003 lead by Canadian neuroscientist Andres Lozano, M.D., Ph.D., who is also a professor at the University of Toronto.
In 2005, Lozano and a colleague, Helen Mayberg, PhD, a neurologist at Emory University in Atlanta, GA, began questioning how people with depression that was resistant to medication and/or behavioral therapy would respond to DBS.
According to Price, Mayberg said, “The study was motivated by a shift in the way science looks at depression. Now we don't think about many brain diseases as being low on some chemical or purely some psychological complex,” she said. “Researchers are paying closer attention to the circuits that connect different areas of the brain.”
In a study of more than 60 people who, since 2005, had undergone DBS for “mood disorders previously resistant to treatment", Price quoted Lozano who explained that approximately 60 percent of those participants saw a "striking improvement in their symptoms of depression."
Lozano explained that researchers believe depression sufferers have certain areas of the brain with an activity set point turned up higher than normal. "It's as if the thermostat in your house is set at 100 degrees instead of 70 degrees," he said. "For genetic reasons or environmental reasons or both, the set point is high in this mood area of the brain. We think that their sadness is in overdrive." Researchers like Lozano believe DBS can help lower the thermostat.
Writer Kylie Gionet, in an article last week for The National Post, described the surgical procedure Lozano performs to produce the deep brain stimulation in patients with depression. “A surgeon drills a small hole into the skull and directs an electrode down into a region called Brodmann area 25, . . . what [Lozano] has referred to as the sadness centre of the brain,” Gionet explained.
“The other end of the electrode is tunnelled down under the skin to a battery, or pacemaker-like device, in the chest,” she added. “Doctors then use a remote control to turn up or down . . . the amount of electricity delivered to that area of the brain.”
Gionet’s article also cites statistics from the World Health Organization that said based on world-wide numbers, depression is the predominant cause of disability. And analyses of people suffering from treatment-resistant depression demonstrates a 33 percent failure to respond to “multiple medications and treatment, such as psychotherapy and electroconvulsive therapy”.
In DBS, the brain stimulation is actually more likened to tapping the brakes of a car. It “puts the brakes on sadness and, over time, sets other areas of the brain in drive,” Gionet explained.
But, “the real work happens afterwards,” Lozano explained. “DBS is not a cure. If stimulation stops, the depression will return. It’s also not a quick-fix.”
An initial clinical trial established by Lozano and Mayberg showed little improvement in depression in the group of participants who received DBS. However, in the second phase of the study, 77 of the original 90 patients took part in a four-year follow-up that showed long-term positive improvement in previously treatment-resistant depressions, suggesting the invasive DBS treatment may take time—a long time—to show progress.
The two scientists’ data showed that, at the two-year mark, 48 percent of the 77 patients had a positive response to the DBS and 25 percent “achieved remission” of their depression symptoms. Of the two parts of the study, Mayberg said, “A failed trial is not a failed treatment . . . It may take longer to get better the more chronically ill you are.”
Although more convincing proof of its efficacy is needed before DBS will be approved for widespread use, the technique is also being used in other studies in an attempt to treat severe cases of another mental health issue—eating disorders, specifically anorexia.
In a Reuters article, reprinted by the Huffington Post, writer Kate Kelland discussed the recent work of scientists who conducted a small test in which 16 participants with severe anorexia found some improvement from “implanting stimulation electrodes into [their] brains”. Although results looked good, Dr. Andres Lozano, also involved in this study, indicated more research—and more patients--will still be needed to test the technique.
References
Gionet, K., (December 21, 2017). National Post. Could an experimental brain surgery make you happier? http://nationalpost.com/news/canada/could-an-experimental-brain-surgery-make-you-happier
Holtzheimer, P.E., & Mayberg, H. S., (April 29, 2015). National Center for Biotechnology Information. PubMed. Deep Brain Stimulation for Psychiatric Disorders. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4413475/
Kelland, K., (February 24, 2017). Huffington Post. Scientists Test Deep Brain Stimulation As Potential Anorexia Therapy. https://www.huffingtonpost.com/entry/scientists-test-deep-brain-stimulation-as-potential-anorexia-therapy_us_58b06122e4b0a8a9b781a218
Price, M., (2009). American Psychological Association. A pacemaker for your brain? http://www.apa.org/monitor/2009/03/pacemaker.aspx
