Major depression is commonly treated with a combination of antidepressants and psychotherapy, but many patients experience little or no improvement with treatment. A recent randomized trial evaluated the efficacy of transcranial magnetic stimulation (TMS) in 199 patients with major depression (current episode < 5 years) that had not responded to up to 4 trials of antidepressant medication. Patients aged 18-70 years were randomized to active TMS vs. sham TMS daily for 15 sessions over 3 weeks. All patients were currently free of antidepressants (with 2 week washout period prior to TMS) and had a Hamilton Depression Rating Scale (HAMD24) score ? 20.
In each 37.5 minute session, treatment was applied to the left prefrontal cortex at 10 pulses per second (120% of resting motor threshold). Patients achieving a drop in HAMD24 score of ? 30% at 3 weeks continued blinded treatment for up to 3 additional weeks. In both groups, patients who did not respond during the initial 3 weeks were given open active treatment for an additional 3 weeks. After stable remission (defined as HAMD < 3 or HAMD24 ? 10 on 2 consecutive measures), TMS was tapered off and antidepressant therapy was begun.
The active TMS group had a significantly higher remission rate at 6 weeks (14.1% [13 patients] vs. 5.1% [5 patients], p = 0.02, NNT 12) ( level 1 [likely reliable] evidence). Patients in the active TMS group were more likely to experience headaches and stimulation site discomfort and were more likely to drop out for adverse events (5.4% vs. 0, NNH 18) (Arch Gen Psychiatry 2010 May;67(5):507).
For more information, see the Transcranial magnetic stimulation for depression topic in DynaMed.