Investigational device-based therapies will lead to entirely new treatment options for patients with chronic depression as early as late 2006, according to a symposium on treatment-resistant depression at the annual meeting of the American Psychiatric Association.

Researchers said that brain stimulation techniques under development such as transcranial magnetic stimulation, vagal nerve stimulation, and deep brain stimulation are emerging as significant treatment options for the millions of patients "poorly served" by existing therapies. Of the 14 million U.S. adults who experience a major depressive disorder each year, 7.2 million receive treatment, and roughly 4 million get little to no relief from existing therapies or are unable to tolerate antidepressant drugs.

"Despite major advances in disease awareness, delivery of care, and safer, more tolerable pharmacologic options, the effectiveness of drug therapy for major depression is fundamentally no better than it was two decades ago," said Dr. Mark A. Demitrack, Chief Medical Officer of Neuronetics, Inc. and chairman of the symposium.

One such emerging therapy, transcranial magnetic stimulation, produces pulses of magnetic energy that are directly targeted at the part of the brain believed to control mood, with the goal of improving the function of these key brain pathways. A clinical trial is currently underway in the US.

"The safety of transcranial magnetic stimulation is well documented in the clinical literature. If the results of the current study show positive antidepressant effects, and if the U.S. FDA clears the technology for marketing, physicians will have an entirely new tool to combat major depression." The company anticipates seeking FDA approval in 2006.