TMS Therapy is a treatment for depression that uses very short pulses of magnetic energy to alter the activity of nerve cells in the brain.
Magnetic fields have been used to modulate the activity of brain tissue for many years and the therapeutic use of this form of brain stimulation now has been examined in a number of clinical research protocols to assess its use as a treatment for major depression. A large, multi-site clinical investigation was conducted by a collaborative team of investigators and supported by Neuronetics., Inc., to evalute the NeuroStar TMS Therapy System. (UCLA was not a participating site in that project.)
The data from that project led to the 2008 clearance by the FDA of the NeuroStar device as a safe and effective method of providing treatment for major depression. Key findings from that trial have appeared in a number of peer-reviewed scientific publications (please see our articles page for details).
We participated in a large, multi-site study of TMS in real-world, care-seeking patients and found improvements not only in the symptoms of depression but also in the quality of life of patients who received TMS (articles page).
Since then, the FDA allowed a second TMS system ("deep TMS" from Brainsway, Ltd.) to be marketed in the United States in 2013. Still other devices and approaches are "in the pipeline" towards review at the US FDA, so the landscape of available TMS neuromodulation therapies is likely going to continue to increase in coming years.
The short pulses of magnetic energy produced by a TMS system are focused at structures in the brain that are involved in the regulation of mood and emotion. Magnetic fields pass unimpeded through the skull and into the top layers of the brain tissue. This facilitates a very focal type of stimulation, minimizing stimulation of brain tissue not involved in mood.
Unlike the static (unchanging) magnetic fields from stationary permanent magnets, the pulsed magnetic field used in TMS exhibits a rapidly changing dynamic, allowing it to induce electrical currents in nearby brain tissue. Although they are small, these induced electric currents in the brain can cause the neurons to fire or become more active. The objective of TMS Therapy is to stimulate (or activate) brain cells as a way to modulate or modify their function. Patients remain awake and alert during a TMS Therapy procedure, and may read, watch video, listen to music, or meditate/relax — whatever will help put an indivdiual in the best possible frame of mind.
Work from our group at UCLA has suggested that, in addition to these aspects of the mechanism of action of TMS, other biologically-important actions may be achieved by lower-energy magnetic fields that use sinusoidal waveforms rather than pulses (please see our articles page). Systems that use this alternative approach to neuromodulation are not approved by the US FDA and, under US Federal Law, are restricted to use in research protocols at this time.