Magnetic Stimulation May Be as Effective as Electroconvulsive Therapy in Treating Severe Depression.
Repetitive transcranial magnetic stimulation, or rTMS, which delivers brief but intense magnetic pulses to the brain, may be as effective as traditional electroconvulsive therapy in treating severe depression, according to a University of Illinois at Chicago study.
That's good news, said Dr. Philip Janicak, medical director of UIC's Psychiatric Clinical Research Center and head of the clinical trial, because rTMS appears to produce fewer harmful side effects than electroconvulsive therapy, better known as shock treatment.
The preliminary results of the UIC trial will be published in a forthcoming issue of Biological Psychiatry. An abstract of the paper is currently available online at www.elsevier.com/locate/biopsych.
In rTMS, a physician uses a hand-held wire coil to produce a controlled, rapidly fluctuating magnetic field with a strength of 1.5 to 2 Tesla, about the same strength used in magnetic resonance imaging but more focused. The coil is placed over the left prefrontal cortex, an area of the brain behind the forehead that in depressed patients typically shows abnormal electrical activity and decreased blood flow. The magnetic pulses pass through the skull into this targeted area. The procedure lasts about 10 to 15 minutes, during which about 1,000 stimulations occur.
Compared with electroconvulsive therapy, which works by inducing a seizure, rTMS is relatively benign, according to Janicak. Sedation is not required, and patients do not appear to experience deterioration in memory or cognition, standard side effects of shock treatment. However, there is a very small risk of an inadvertent seizure.
"Patients might feel their facial muscles contract at the time of treatment and may have a mild headache afterward, but that's all," Janicak said.
A total of 25 patients with either bipolar depression (also known as manic depression) or unipolar depression have thus far participated in the UIC study. They were randomly assigned to undergo a course of either transcranial magnetic stimulation (10 to 20 treatment sessions) or bitemporal electroconvulsive therapy (4 to 12 treatments).
Following treatment, the patients were assessed using the Hamilton Depression Rating Scale, a widely used psychological test that evaluates mood, feelings of guilt, agitation, sleep problems, work capacity and interest, as well as other symptoms of depression.
Both groups of patients showed significant improvement in their baseline depression scores, with a 55 percent reduction on the Hamilton Depression Rating Scale for the rTMS group and a 64 percent reduction for the electroconvulsive therapy group. The difference between the two groups was not statistically significant.
The two groups also performed similarly on other clinical measures of mood and behavior.
"rTMS is a promising alternative, particularly for the many severely depressed patients who do not benefit from or tolerate current established treatments," said Janicak.
According to Janicak, how rTMS works is still not clear. One theory suggests that the magnetic stimulation increases blood flow and chemical activity in the affected area of the brain.
Depression is common in the United States. Up to 20 percent of the population will experience at least one episode of depression over a lifetime. Further, as many as one-third of these episodes will be severe or not managed adequately by existing treatments.
