The first large-scale, sham-controlled study of transcranial magnetic stimulation shows that it is effective as monotherapy for major depression resistant to other antidepressant therapies, according to an article in the December 1 issue of Biological Psychiatry.

Co-author Philip Janicak, MD, professor of Psychiatry at Rush University Medical Center, said the treatment may be an option for patients with major depression who have not responded to conventional antidepressant medications.

Transcranial magnetic stimulation, a noninvasive technique that excites neurons in the brain by magnetic pulses introduced through the scalp, has previously been identified as a potential new treatment for depression but prior, smaller studies produced conflicting results.

The current study was the first large-scale, multi-center, double-blind, sham-controlled study of treatment for people with depression who had not responded to prior antidepressants and who were not taking antidepressant medications during the study.

In the study, 301 patients who were medication free at time of enrollment and whose major depression had not responded to prior treatment were randomized to active or sham transcranial magnetic stimulation over the left dorsolateral prefrontal cortex five times per week for four to six weeks.

Primary outcome was the symptom score change assessed at week 4 with the Montgomery-Asberg Depression Rating Scale (MADRS). Secondary outcomes included changes on the 17- and 24-item Hamilton Depression Rating Scale (HAMD17 and HAMD24) and response and remission rates with both scales. Response rates were significantly higher at week 4 and week 6 with all three scales; remission as assessed at week 6 were approximately twofold higher with active treatment and significant on the MADRS and HAMD24 scales (but not the HAMD17 scale).

The study was also associated with a low dropout rate of 4.5 percent, due to generally mild side effects such as scalp pain, indicating that the treatment was well-tolerated by patients.

John P. O'Reardon, MD, the corresponding author and associate professor of Psychiatry at the University of Pennsylvania, explained, "These results indicate that transcranial magnetic stimulation provides a novel and attractive treatment option for patients with major depression who have not responded to conventional antidepressant medications."

John H. Krystal, MD, editor of Biological Psychiatry, highlighted the significance of this article's findings: "This study provides new support for the efficacy of transcranial magnetic stimulation as a 'stand alone' treatment for depression. This finding could be particularly important for patients who do not tolerate antidepressant medications, for whom they are not safe, or who have not benefited from other alternative treatments."

O' Reardon added, "As indicated by recent large scale, government-sponsored, studies of existing treatment options for major depression conducted by the National Institute of Health (the STAR-D reports), there is a great need to develop new effective treatments for patients, especially those not benefiting from first line interventions. The results of this study indicate that transcranial magnetic stimulation offers new hope to patients in this regard."