Deep brain stimulation can durably improve depression symptoms in people who don’t respond well to other treatments, according to a study. The findings, based on up to eight years of data from 28 people wearing brain-stimulating implants, showed that most people receiving the therapy responded well and maintained their improvements over time. Deep brain stimulation, or DBS, involves implanting a small neurostimulator into a patient’s brain to send out electrical impulses to specific brain regions. The approach is approved by the US Food and Drug Administration to treat epilepsy and Parkinson’s disease, among other conditions, but has long been controversial in depression treatment due to mixed findings of the treatment’s effectiveness in the last couple decades.
Robust and sustained’ response
For the new study, the researchers analyzed data that they had collected over 4–8 years on 28 people participating in an open label clinical trial of deep brain stimulation of SCC for depression that had not responded to other treatments. Of the participants, 20 had major depressive disorder, and seven had bipolar II, a form in which the manic episodes, or “highs,” are less extreme. The 28th participant had an initial diagnosis of major depression but then received a diagnosis of bipolar II. The results showed that response rates stayed at or above 50%, while remission rates stayed at or above 30% during 2–8 years of follow-up.
Just over one-fifth (21%) of the participants showed continuous response to treatment for the whole of their follow-up after the first year. In addition, for three-quarters of the group, a robust response to treatment held for at least half of their follow-up. Of the 28 participants, 14 completed at least 8 years of follow-up, and another 11 completed at least 4 years. “While clinical trials generally are structured to compare active and placebo treatments over the short term,” observes first and corresponding study author Dr. Andrea L. Crowell, “our research results suggest that the most important strength of [deep brain stimulation] in this hard-to-treat clinical population lies in its sustained effects over the long term.”