January 6, 2012

Deep Brain Stimulation for Depression

(Ivanhoe Newswire) — Bipolar spectrum disorder affects both men and women; and often signs of the disorder began to surface between the ages 15 — 25. Bipolar spectrum disorder, most times referred to as manic-depression, is characterized by bouts of mania or hypomania alternating between episodes of depression. These bouts or "mood swings" between mania and depression can happen rather quickly and are typically very intense; there is also a high risk of suicide. A major challenge in treating bipolar depression is that many antidepressant medications may cause patients to "switch" into a hypomanic or manic episode, but there is hope.

A new study led by Helen S. Mayberg, MD, professor in the Departments of Psychiatry and Behavioral Sciences and Neurology at Emory University School of Medicine, with co-investigators Paul E. Holtzheimer, MD, lead psychiatrist, and neurosurgeon Robert E. Gross, MD, PhD, shows that deep brain stimulation (DBS) is a safe and effective intervention for treatment-resistant depression in patients with either unipolar major depressive disorder (MDD) or bipolar II disorder (BP).

Seventeen patients participated in this study and most of the participants were already experiencing bouts of depression for many years. Each study participant was implanted with two thin wire electrodes, one on each side of the brain. The other end of each wire was connected under the skin of the patient´s neck to a pulse generator implanted in the chest–similar to a pacemaker–that directs the electrical current. DBS uses high-frequency electrical stimulation targeted to a predefined area of the brain specific to the particular neuropsychiatric disorder. Participants received single-blind stimulation for four weeks (patients did not know if the DBS system was on or off), followed by active stimulation for 24 weeks. Patients were evaluated for up to two years following onset of active stimulation.

The study showed a significant decrease in depression and an increase in function with continued stimulation. Remission and response rates were 18 and 41 percent after 24 weeks; 36 and 36 percent after one year; and 58 and 92 percent after two years of active stimulation. Patients who achieved remission did not experience a spontaneous relapse nor a manic or hypomanic episode.

"Depression is a serious and debilitating medical illness," says Mayberg. It disables as well as causes many of those affected to feel isolated and alone. Mayberg and her colleagues continue their efforts to refine their intervention. Some of their current studies include demographic, clinical and imaging predictors of response and remission, and introduction of psychotherapeutic rehabilitation. Why and how this treatment works is the primary focus of ongoing research.

Mayberg and her colleagues´ hope says Holtzheimer is "to optimize the rate of improvement by using a model of care that provides psychotherapeutic rehabilitation built on evidence-based psychotherapy but tailored to the specific individual´s situation."

SOURCE: Archives of General Psychiatry, January 2012.