Researchers from the Cleveland Clinic and Brown University’s Butler Hospital will present results of a study that shows deep brain stimulation (DBS) to be a potentially effective treatment option for people with major depression.

An estimated 9.5 percent of the population, or about 18.8 million American adults, suffer from a depressive disorder each year. The financial impact of these disorders is very high, costing as much as $40 billion annually in the American workplace. The United States is not alone in experiencing this major public health crisis. The World Health Organization rates major depression as the top cause of disability worldwide. While many patients with major depression find relief through a combination of psychotherapy and medication, some people are left severely disabled.

The results of this study, Deep Brain Stimulation for the Treatment of Intractable Major Depression: Preliminary Results from a Multi-Center Prospective Trial, will be presented by Ali R. Rezai, MD, 11:30 to 11:45 a.m. on Tuesday, April 25, 2006, during the 74th Annual Meeting of the American Association of Neurological Surgeons in San Francisco. Co-authors are Gerhard Friehs, MD, Donald A. Malone, MD, Linda L. Carpenter, MD, Andre G. Machado, MD, PhD, Audrey R. Tyrka, MD, PhD, Lawrence H. Price, MD, Steven Rasmussen, MD, Cynthia S. Kubu, PhD, and Benjamin D. Greenberg, MD, PhD. “Since 2001, this team of investigators has been using DBS for treatment of obsessive compulsive disorder (OCD). Because DBS for OCD showed significant benefits in improving patient’s anxiety and obsessions, as well as improvements in co-morbid depression, the research team initiated a new study analyzing the effects of DBS on patients with major depression,” stated Dr. Rezai.

DBS has been used to treat intractable pain for several decades, and more recently, use of this technology has expanded to the FDA-approved indications for Parkinson’s disease and other movement disorders. DBS is also under investigation in the treatment of epilepsy and other debilitating neurological conditions. DBS surgery involves the placement of tiny implantable electrodes into specific parts of the brain that are functioning abnormally. These electrodes emit tiny pulses of electrical stimulation to block the abnormal activity in the brain, which causes a variety of symptoms -  such as pain, tremors, movement problems; as well as obsessions, moods and anxieties associated with psychiatric disorders. The success of DBS is dependent on the surgical team’s ability to precisely pinpoint the specific brain area for stimulation. The advantage of DBS is that it is reversible, nondestructive, and can be modified by adjustment of the stimulator settings after implantation.

This study was conducted with Institutional Review Board (IRB) and Food and Drug Administration (FDA) Investigational Device Exemptions (IDE) approval. Six patients, four females and two males, with an average age of 48, were enrolled in the study from 2003 to 2005. All six patients had a history of being highly resistant to other treatments, including medication, psychotherapy, and electroconvulsive therapy (ECT). Bilateral DBS leads were implanted stereotactically in a region of the brain known as the ventral anterior internal capsule. Participants underwent standardized and detailed psychiatric, quality-of-life, and neuropsychological assessments on a regularly scheduled basis, both pre- and postsurgically.

At a minimum of six months postsurgery, four of the six patients showed a clinically significant reduction in depression severity of 50 percent or greater on the Montgomery-Asberg Depression Rating Scale. Quality-of-life measures improved as well, and patients showed progressive improvements in mood and functioning over time. One patient experienced persistent occipital pain that was alleviated with repositioning of a subcutaneous connector wire.

“Overall, preliminary results indicate that bilateral DBS of the anterior limb of the internal capsule holds promise for the treatment of intractable major depression,” stated Dr. Rezai.

Results of the first study, Deep Brain Stimulation for the Treatment of Intractable Obsessive Compulsive Disorder: Long-Term Outcome from a Multi-Center Prospective Trial, will also be presented by Dr. Rezai at the AANS meeting, 2:45 to 3:00 p.m., Monday, April 24, 2006. Co-authors of this study are Gerhard M. Friehs, MD, Donald Malone, MD, Steven A. Rasmussen, MD, Cynthia S. Kubu, PhD, Andre G. Machado, MD, PhD, Paul F. Malloy, PhD, and Benjamin D. Greenberg, MD, PhD.

While OCD is not as prevalent as depression, it does affect 2 to 3 percent of the United States population, and at least 10 percent of patients have disabling cases that are resistant to treatment. “In following nine patients for a minimum of two years, we concluded that bilateral DBS of the anterior limb of the internal capsule is a safe and effective therapy for patients with intractable OCD that were previously unresponsive to all other available therapeutic alternatives,” remarked Dr. Rezai.

Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 6,800 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons (Neurosurgery) of Canada or the Mexican Council of Neurological Surgery, AC. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system, including the spinal column, spinal cord, brain and peripheral nerves.