TMS vs ECT

So how is TMS different from ECT? Both treatments use some form of electricity to stimulate the brain. But apart from this similarity there are a number of important differences. For one thing ECT is always given under general anesthesia. TMS is always given while a person is awake. A course of TMS is a bit longer than an average course of ECT, but it's a lot more convenient since it's always done as an outpatient procedure. And because there's no anesthesia used, patients can drive themselves to and from treatment. It's also a lot less expensive. But the most important difference is that TMS is virtually free of side effects.

ECT always causes temporary confusion. And it often causes temporary--but sometimes significant--memory problems. Plus, it has significant effects on the cardiovascular system which can be an issue for some patients. TMS causes none of these problems.

These different side effect profiles are due to the different ways in which these two treatments act upon the brain.

ECT stimulates the entire cerebral cortex. TMS stimulates only a small part of the cortex. And whereas ECT stimulates the entire brain, from the cortex all the way to the brainstem, TMS stimulates only the outer layers of the cortex and primarily the pyramidal cells in layer 5. But these pyramidal cells communicate with other cells. Although the magnetic field doesn't penetrate deeply, ultimately TMS treats depression by acting on the deep limbic mood circuits.