Public Release: 

Treatment-Resistant Depression: Results of Latest Electromagnetic Stimulation Study Show Promise

Emory University Health Sciences Center

WASHINGTON, D.C. -- An investigational treatment employing electromagnetic stimulation relieved depression in 25 patients whose depression failed to respond to conventional treatment, report Emory University researchers at this week's American Psychiatric Association meeting.

Scores on depression rating scales administered to study subjects before, during and after the new treatment "were significantly improved at all time points compared to baseline," says first author Yvonne M. Greene, M.D., in the abstract; Dr. Greene is a neurosciences fellow at the Emory University School of Medicine and has collaborated on the open trial with William McDonald, M.D., associate professor of psychiatry and behavioral sciences at the Emory University School of Medicine, and others.

"Sixty-four percent of patients were rated 'very much improved' or 'much improved' on the (CGIC) Clinical Global Impression of Change and 40 percent of patients had an equal to or greater than 50 percent decrease in HDRS (Hamilton Depression Rating Scale) scores at the end of treatment week two. Forty percent of patients were rated 'very much improved' or 'much improved' on the CGIC and 32 percent of patients had an equal to or greater than 50 percent decrease in HDRS scores at the end of the four-week followup.

"These results suggest rTMS (repetitive transcranial magnetic stimulation) may be a viable option for patients with treatment-resistant depression," the authors say.

Prior to receiving rTMS, "There were an average of seven antidepressant failures per patient and eight patients had failed electroconvulsive therapy (ECT)," they say.

"rTMS involves passing current through an electromagnetic coil to generate a magnetic field," they explain. "The magnetic field acts as the medium between electricity in the coil and induced electrical currents in the brain. The current depolarizes neurons in the brain up to a depth of about two centimeters below the brain's surface. Unlike ECT for depression, rTMS does not require anesthesia or analgesics."

Study subjects were antidepressant-free for one week prior to rTMS and received 10 daily treatments (10 trains of five seconds each, 25 seconds apart) at a frequency of 10 Hz. Seventy-eight percent of patients experienced mild-moderate discomfort at the site of stimulation, two patients who experienced severe pain in the treatment site dropped out of the study and eight percent of patients experienced a posttreatment headache.

The mean age of patients treated was 52 years. " rTMS seems most promising for older adults and for treatment-resistant patients with depression," says Dr. McDonald, who directs the Fuqua Center for Late-Life Depression at Wesley Woods.

Also collarborating on the study were Charles M. Epstein, M.D., associate professor of neurology at Emory; Liquong He, M.D., formerly with Emory; Autumn L. Clark, B.S., study coordinator in Emory's department of psychiatry and behavioral sciences; Fred A. Marstellar, Ph.D., associate professor of psychiatry and behavioral sciences at Emory; and John Woodard, Ph.D., of the Georgia State University Memory Assessment Clinic.

The study was supported by a private grant from the Fuqua Foundation.


b a c k g r o u n d - - - (originally issued April 1998)


  • In addition to mood, transcranial magnetic stimulation has been used to evaluate brain function in vision, memory, attention, speech and movement, including Parkinson's disease.

  • Medical University of South Carolina professor Mark George conducted early work applying rTMS to the treatment of depression while he was at the National Institute of Mental Health. He reported in 1994 that two of six treatment-resistant patients improved after prefrontal cortex stimulation by rTMS.

  • Alvaro Pascual-Leone, currently at Brigham and Women's Hospital in Boston, conducted a crossover placebo controlled study with five different treatment conditions. His team reported in 1996 that 11 of 17 patients under 60 years of age with psychotic or drug-resistant depression benefited from left pre-frontal electromagnetic stimulation.
    Charles M. Epstein, M.D., Gary S. Figiel, M.D., William M. McDonald, M.D., Jody Amazon-Leece, MS, GNP, and Linda Figiel, RN, MSN "Rapid Rate Transcranial Magnetic Stimulation in Young and Middle- Aged Refractory Depressed Patients" Psych Annals 28:1/January 1998.

  • Thirty-two patients were enrolled (16 women, 16 men) in the study and 28 completed the five days of rTMS treatment administered by Emory University School of Medicine physicians at Wesley Woods Geriatric Center. Ages ranged from 22 to 64 years with a mean age of 40. All patients met DSM-IV criteria for a major depressive episode.

  • Sixteen patients (56 percent) responded positively to the treatment. Those patients who benefited from rTMS did not differ from nonresponders with respect to age, sex or pretreatment scores on the Hamilton Depression Scale.
    Gary S. Figiel, M.D., Charles Epstein, M.D,. William M. McDonald, M.D., Jody Amazon-Leece, M.S., GNP, Linda Figiel, RN, MSN, Aida Saldivia, M.D., Susan Glover, M.D. "The Use of Rapid Rate Transcranial Magnetic Stimulation (rTMS) in Refractory Depressed Patients" Jrl Neuropsych & Clin Neurosci, March 1998.

  • The largest patient series at that time applying rTMS to depression.

  • Fifty-six patients with medication-resistant depression enrolled in the study and 50 (26 women and 24 men) completed the course of five rTMS treatments. Patients ranged in age from 22 to 89 with a mean age of 60. The 28 subjects under age 65 were placed in the "young" group and the remaining 21 were classified as members of the "elderly" group. Among subjects in the young group, 56 percent responded positively to the treatment, compared with 23 percent in the elderly group.

  • "We have previously reported on the increased incidence of structural brain changes in elderly depressed patients and that elderly patients with late-onset (first episode occurring after age 65) depression have the most severe structural brain changes. These findings may explain the poor response from rTMS observed in our elderly, depressed patients. At our institution, we are currently examining whether pre-existing structural brain changes in the depressed elderly may predict a poor response from rTMS," the authors report. Patients were considered responders if they showed significant improvement in depressive symptoms as measured by a series of standard questionnaire-based mood rating scales administered before and after rTMS. In total, 21 (42 percent) of the 50 study participants responded to rTMS.

  • Study subjects who responded positively to rTMS tended to be younger. Responders did not differ from nonresponders in regards to gender or pretreatment scores on the Folstein Mini Mental Examination, another mood-rating scale.

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