Deep Brain Stimulation Offers Hope for Treatment Resistant Patients

On April 19, 2008, during the 76th Annual Meeting of the American Association of Neurological Surgeons in Chicago, researchers from the Cleveland Clinic, Brown University and Massachusetts General Hospital presented the results of a study indicating that deep brain stimulation (DBS) may be an effective option for treatment resistant major depression.

According to Psychiatric Secrets, 2nd ed., treatment resistance is frequently defined as failure to respond to an adequate trial of at least two standard antidepressants. Treatment resistant patients may also initially respond to an antidepressant, but quickly develop a tolerance to it.

DBS is a surgical procedure which involves implanting small electrodes in the areas of the brain with abnormal function. These electrodes emit tiny pulses of electrical stimulation to block the abnormal brain activity.

In order for DBS to work well, surgeons must be able to precisely target the correct area to stimulate.

DBS offers several advantages because it reversible, nondestructive and can be modified by adjusting the settings after implantation.

Lead author Dr. Ali R. Rezai and his colleagues enrolled fifteen chronic and severely depressed patients in their study. These patients had failed multiple medication trials as well as psychotherapy and electroconvulsive therapy (ECT). During the study, the patients underwent DBS implantation on both sides of the brain in the ventral internal capsule/ventral striatum areas.

When they evaluated the patients' outcome, they found that:

• A response was seen in seven out of the 15 patients at six months, five patients of 11 at 12 months and eight out of the 15 at the final follow-up.
• The patients were able to acheive long-term improvement in depression severity and the patients' functioning and quality of life.
• Measures of short-term memory improved.
• The patients had no bleeding, infections or other neurological problems.

“This research substantiates our earlier findings, which indicate that bilateral DBS of the anterior limb of the internal capsule holds promise and hope for select patients suffering from severe and treatment resistant major depression," Dr. Rezai said in a press release. “While about half of this patient group responded to treatment, I feel that as we learn more about this rather new technology, efficacy will continue to improve. It is important to understand that this treatment is not for everyone with major depression and only for those that have tried various medications, psychotherapy and ECT. But, nevertheless, it is very promising news for the many suffering patients and their family members that have virtually given up hope.”

Dr. Rezai will be presenting the results of a similar study involving DBS as a treatment for obsessive-compulsive disorder on April 28.