I guess I have to eat humble pie. Last year I posted a 'Saturday Quack' pointing out that magnet therapy has no proven medical benefits. At that time the British National Health Authority had approved its use for speeding wound healing, in spite of the lack of any good evidence. Now there's a report in Biological Psychiatry of magnetic stimulation showing effectiveness in major depression.

As many as 40% of patients with major depression are resistant to medication and psychotherapy. Over 300 such patients were randomly allocated to have active transcranial magnetic stimulation (discharge of a time-varying current from an insulated coil placed on the scalp surface) or a similar but sham procedure. Sessions were scheduled 5 times a week for 4-6 weeks. Using two recognized rating scales, symptoms of depression were found to be significantly reduced in the actively treated compared with the sham-treated patients at week 4.

What about side effects, the bane of most antidepressant medications? Magnetic stimulation led to a 4.5% dropout rate for adverse effects; these were generally mild, and limited to temporary scalp discomfort or pain.

So transcranial magnetic stimulation appears to be an effective treatment for resistant depression. The apparatus used is called NeuroStar® and it's made by Neuronetics Inc. However, it will take further studies in a large number of patients before the approach receives FDA approval for general use.