Health

PREVIOUSLY touted as a possible treatment for migraine, stroke and even coma, transcranial magnetic stimulation (TMS) has been given its first official stamp of approval by the US Food and Drug Administration - as a treatment for depression in people who fail to respond to antidepressant drugs.

In TMS, an electromagnetic coil is held over the patient's head to induce a weak electric current in their brain tissue. Several large trials have suggested it can be useful in treating depression, as the coil's rapidly changing magnetic fields excite cells in the areas of the brain involved in mood regulation. Neuronetics of Malvern, Pennsylvania, says that in the latest trials it submitted to the FDA more than half of depressed people treated showed an improvement in symptoms after receiving five 40-minute TMS sessions per week for four to six weeks.

The FDA's approval may prompt a flood of companies hoping to get TMS approved in other countries. "It is a very significant step forward, as everyone looks to the US as the leader," says Andrew Thomas of the UK-based company, Magstim.

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