So now there is a published study, sponsored by the NIH, that used a good double-blind method. It used a sham procedure that mimics the sensation of active treatment, while blocking the magnetic field. It was a multicenter study that included 190 patients. The conclusion: "Daily left prefrontal rTMS as monotherapy produced statistically significant and clinically meaningful antidepressant therapeutic effects greater than sham." Sounds good, right?
Daily Left Prefrontal Transcranial Magnetic Stimulation Therapy for Major Depressive Disorder
A Sham-Controlled Randomized Trial
Arch Gen Psychiatry. 2010;67(5):507-516.
So yes, the conclusion sounds good. The study was done carefully, using acceptable methodology. Skeptics, however, may find reason to cast doubt: although the study was funded by an impartial agency, some of the authors do have industry connections, for example:
Context Daily left prefrontal repetitive transcranial magnetic stimulation (rTMS) has been studied as a potential treatment for depression, but previous work had mixed outcomes and did not adequately mask sham conditions.
Objective To test whether daily left prefrontal rTMS safely and effectively treats major depressive disorder.
Design Prospective, multisite, randomized, active sham-controlled (1:1 randomization), duration-adaptive design with 3 weeks of daily weekday treatment (fixed-dose phase) followed by continued blinded treatment for up to another 3 weeks in improvers.
Setting Four US university hospital clinics.
Patients Approximately 860 outpatients were screened, yielding 199 antidepressant drug-free patients with unipolar nonpsychotic major depressive disorder.
Intervention We delivered rTMS to the left prefrontal cortex at 120% motor threshold (10 Hz, 4-second train duration, and 26-second intertrain interval) for 37.5 minutes (3000 pulses per session) using a figure-eight solid-core coil. Sham rTMS used a similar coil with a metal insert blocking the magnetic field and scalp electrodes that delivered matched somatosensory sensations.
Main Outcome Measure In the intention-to-treat sample (n = 190), remission rates were compared for the 2 treatment arms using logistic regression and controlling for site, treatment resistance, age, and duration of the current depressive episode.
Results Patients, treaters, and raters were effectively masked. Minimal adverse effects did not differ by treatment arm, with an 88% retention rate (90% sham and 86% active). Primary efficacy analysis revealed a significant effect of treatment on the proportion of remitters (14.1% active rTMS and 5.1% sham) (P = .02). The odds of attaining remission were 4.2 times greater with active rTMS than with sham (95% confidence interval, 1.32-13.24). The number needed to treat was 12. Most remitters had low antidepressant treatment resistance. Almost 30% of patients remitted in the open-label follow-up (30.2% originally active and 29.6% sham).
Conclusion Daily left prefrontal rTMS as monotherapy produced statistically significant and clinically meaningful antidepressant therapeutic effects greater than sham.
Dr. George reports receiving research grants in the past 5 years from Brainsway, Cephos, Force Protection, GlaxoSmithKline, and Jazz Pharmaceuticals. He has been an unpaid adviser to Brainsonix, Neostim, Neosync, and Neuronetics Inc (because they make products related to TMS) and a paid adviser to Cyberonics, Jazz, Neuropace, and Puretech ventures. The full amount of his advisory income has never been more than 10% of his university salary. The Medical University of South Carolina has 2 patent applications in Dr George's name on combining TMS with magnetic resonance imaging.
This sort of connection is not unusual, but it is wise to not completely ignore it when interpreting the study.
How good were the results? Active treatment was associated with a remission rate of 14.1%, compared to 5.1% in the sham-treatment group. This is not a startlingly great remission rate. However, it is a lot better than doing nothing.
Comments
Pretty nice. It must be one of the largest studies of tms treatment of depression. Unfortunately, each paper on treatment of psychiatric conditions with TMS comes with different TMS parameters (frequency, intensity, duration, etc) so it's hard to compare across studies.
Posted by: mxh | May 26, 2010 11:47 PM
interesting, that was one of the most aggressive studies too in terms of stimulation, it's frustrating they did not post the response rate in the abstract as opposed to remission which is usually rarer; I would imagine that to be much higher, does anyone know the actual response rate?
Posted by: John Princiotta | August 11, 2010 11:14 PM
This TMS is really expensive and it's hard to get insurance companies to pay for it, given the lack of replicated studies with larger sample sizes. For my less well-heeled patients interested in this, I suggest buying huge, industrial grade magnets and putting them under their pillows. Should be the same, right?
Posted by: LottieM | August 29, 2011 2:51 AM