Treatment-resistant depression responded to magnetic brain stimulation in trial

Treatment-resistant depression responded to magnetic brain stimulation in trial

A treatment that uses magnetic currents to stimulate parts of the brain appeared to induce remission in patients with treatment-resistant depression, concluded researchers who tested the method in a randomized trial.

You can read a report on the National Institute of Mental Health funded trial online in the May issue of Archives of General Psychiatry. The research was the work of first author Dr Mark S. George, from the Brain Stimulation Division, Department of Psychiatry, at the Medical University of South Carolina, Charleston, and colleagues from this and other research centers in the US.

For some patients with depression, a disabling disease that is costly to treat, psychotherapy and drugs don't work, and some researchers have suggested that daily transcranial magnetic stimulation (rTMS) of the left prefrontal brain may be an effective alternative.

However, while rTMS has been studied as a potential treatment for depression, the quality of previous research is questionable, said the authors, explaining that one of the problems is how to mask the "sham" condition.

When designing a trial to test a device as opposed to a drug, the equivalent to controlling for the placebo effect is to mask the "sham" condition, ie hiding from participants whether they are receiving "real" exposure or a "sham".

To mask the "sham" condition in this study, George and colleagues blanked off the magnetic field with a metal plate inserted in the rTMS device. Thus some participants were exposed to a "real" magnetic field (the treatment group), and others were exposed to a "sham" magnetic field (the control group), but none of them knew which group they were in.

They recruited 190 patients with depression who were not on medication and ramdomly assigned 92 to the treatment group and 98 to the control or "sham" group. The patients were attending 4 US university hospital clinics.

The treatment group received magnetic stimulation of the left prefrontal cortex for 37.5 minutes every day for three weeks.

The control group received a sham treatment that gave them the same sensory feeling of being stimulated using a similar coil and electrodes attached to the scalp but no exposure to a magnetic field: the plate was in place inside the device.

86 per cent of the treatment group and 90 per cent of the sham group completed the treatment. Among these the results showed that:

  • For 14.1 per cent of the treatment group, their depression went into remission.
  • This compared with 5.1 per cent in the sham group.
  • The odds of achieving remission were 4.2 times greater in the treatment group.
  • In other words, for every 12 patients receiving this treatment, 1 would remit from depression.
The researchers concluded that:

"Daily left prefrontal rTMS as monotherapy produced statistically significant and clinically meaningful antidepressant therapeutic effects greater than sham."

They noted that "patients, treaters, and raters were effectively masked", and in fact this was one of the most important aspects of the study:

"... no one who knew the randomization status of the patient ever came in contact with the patient or interacted with the data," they wrote, explaining that they developed a new sham system that simulated the stimulation experience so it felt the same as the real thing.

At the end of the treatment phase, patients, treaters and clinical raters (who assessed the patients' depression) were asked to guess which group they were in: the treatment or the sham group. Only the treaters guessed at a rate that was more accurate than chance, but they were not very confident of their responses, said the authors.

"Daily Left Prefrontal Transcranial Magnetic Stimulation Therapy for Major Depressive Disorder: A Sham-Controlled Randomized Trial."

Mark S. George; Sarah H. Lisanby; David Avery; William M. McDonald; Valerie Durkalski; Martina Pavlicova; Berry Anderson; Ziad Nahas; Peter Bulow; Paul Zarkowski; Paul E. Holtzheimer III; Theresa Schwartz; Harold A. Sackeim.

Arch Gen Psychiatry, Vol. 67, No. 5, May 2010.

Source: JAMA/Archives.

Bipolar Disorder & Bipolar Depression Treatment with TMS (Video Medical And Professional 2020).

Section Issues On Medicine: Psychiatry