Department of Psychiatry conducting depression studies (11-16-99)
Faculty researchers in the Departments of Psychiatry, Pharmacology and Medicine at The University of Texas Health Science Center at San Antonio are conducting two complementary studies on depression.
The first is designed to determine why individuals with major depression have an increased risk of developing ischemic heart disease (a very common heart condition caused by atherosclerosis, or hardening of the arteries). Depressed individuals who have completed that study are then encouraged to join the second study, which offers treatment with antidepressants.
Stephen Stern, M.D., professor of psychiatry, and fellow researchers are seeking both physically healthy patients with major depression and healthy people without depression for a procedure that will measure the sensitivity of their blood vessels to the stress neurotransmitter norepinephrine. "We know that depression affects the stress system," Dr. Stern said. "We need to figure out if thatís how it leads to heart disease."
Previous studies have shown that people with high blood pressure respond differently to norepinephrine than people without hypertension. Norepinephrine can cause blood vessels to constrict and can stimulate platelet activation, which eventually can lead to atherosclerosis in the coronary arteries and to ischemic heart disease.
The Health Science Center study is examining whether depressed patients will have the same reaction to norepinephrine as those with high blood pressure. Using a measure developed by Dean Kellogg, Jr., M.D., Ph.D., assistant professor of medicine, researchers treat the forearm skin of depressed patients and normal control subjects with a small amount of norepinephrine and measure skin blood flow. They also measure blood levels of stress hormones, study platelet activation and evaluate how subjectsí blood clots.
The study will continue through June, Dr. Stern said. It is being conducted at the Frederic C. Bartter General Clinical Research Center, located at the South Texas Veterans Health Care Systemís Audie Murphy Division.
Participants are paid for their time and do not need to be veterans. At the first visit, participants have a thorough psychiatric and medical examination. On the second visit, norepinephrine is applied to the skin and blood samples are drawn. After the second appointment, the depressed subjects are encouraged to seek treatment by participating in a methodological study of antidepressant medications.
The researchers on the second study, Stephen Brannan, M.D., and John Houston, M.D., Ph.D., faculty members in the Department of Psychiatry, and Alan Frazer, Ph.D., chairman of the Department of Pharmacology, are looking at how rapidly people respond to antidepressant medications. They contend that depressed patients begin to show whether or not a medication is working as soon as 10 days after the initial dose, rather than four to six weeks as commonly thought.
Participants are first screened for depression through a psychiatric interview, a test of concentration, and videotaping of facial expression and motor movement. In consultation with the patient, the psychiatrist determines which medication to prescribe, generally a selective serotonin reuptake inhibitor (SSRI). No placebos are prescribed. The subjects make 10 visits to their psychiatrists over the following six weeks.
"How a patient responds after 10 days will determine how that patient is going to react in six weeks," Dr. Brannan said, adding if a study participant is not responding to a medication after 10 days, the psychiatrist can prescribe a different one.
The study will continue for six to nine months, with a possible extension.
For more information on the medication study, call (210) 617-5300, ext. 4472. For the heart disease study, call (210) 567-5463.
Contact: Will Sansom or Jennifer Lorenzo