Study compares settings of vagus nerve stimulation for treatment-resistant depression

SAN ANTONIO (Aug. 22, 2008)— A team in the UT Health Science Center San Antonio Department of Psychiatry is assessing the effectiveness of three treatment settings of Vagus Nerve Stimulation (VNS) TherapyTM in patients with treatment-resistant depression (TRD) as part of a multi-site research study.

Major depression is a leading cause of suicide, and many who suffer from it do not respond to conventional treatment. “The more agents that do not help a depressed person, the more at risk that person is to harm himself,” said Peter M. Thompson, M.D., San Antonio study principal investigator and associate professor of psychiatry at the Health Science Center. “People with depression are 35 times more likely to commit suicide. Chronic depression can lead to the same sense of hopelessness that chronic pain or cancer does. That is why this study is important.”

VNS Therapy represents new hope for this subset of patients with TRD, Dr. Thompson said. The U.S. Food and Drug Administration approved VNS Therapy in 2005 as an adjunctive long-term treatment for chronic or recurrent depression in patients, age 18 or older, who are experiencing a major depressive episode and have not had an adequate reaction to four or more antidepressant treatments. It is the only device ever studied and approved for TRD.

VNS Therapy is delivered from a small pacemaker-like device implanted in the chest area that sends mild pulses to the brain via the vagus nerve in the neck.

The implant procedure lasts one to two hours and is performed by Daniel D. Tamez Jr., M.D., in the Baptist Health System, San Antonio. Several patients are already enrolled in the research study, and Dr. Thompson continues to enroll subjects at the UT Health Science Center.

The researchers hope to learn which treatment setting gives patients the most relief from their depression while being the best tolerated. Patients must be 18 or older. To ask about eligibility, call Anna Hernandez, R.N., research study coordinator in the Department of Psychiatry, at (210) 567-0780. The four-year study is sponsored by Cyberonics Inc.



The University of Texas Health Science Center at San Antonio is the leading research institution in South Texas and one of the major health sciences universities in the world. With an operating budget of $576 million, the Health Science Center is the chief catalyst for the $15.3 billion biosciences and health care sector in San Antonio’s economy. The Health Science Center has had an estimated $35 billion impact on the region since inception and has expanded to six campuses in San Antonio, Laredo, Harlingen and Edinburg. More than 23,000 graduates (physicians, dentists, nurses, scientists and allied health professionals) serve in their fields, including many in Texas. Health Science Center faculty are international leaders in cancer, cardiovascular disease, diabetes, aging, stroke prevention, kidney disease, orthopaedics, research imaging, transplant surgery, psychiatry and clinical neurosciences, pain management, genetics, nursing, allied health, dentistry and many other fields. For more information, visit

Share This Article!