Doctor Uses Brain Stimulation to Treat Depression
New York (Nov 26, 2009)
Research at NewYork-Presbyterian Hospital and other centers has led to the recent FDA approval of transcranial magnetic stimulation (TMS) for the treatment of depression in patients who do not respond to a single antidepressant medication trial. The approval has opened the door to new treatment options for the more than 50% of patients who fail to respond to an initial course of antidepressant medication.
How TMS Works
In transcranial magnetic stimulation, magnetic fields are sent through the scalp and skull to a particular area of the brain. When the magnetic field enters the brain it creates a small electrical current. This electrical current stimulates the brain cells (neurons) in a targeted brain area and causes them to fire (or send an electrical impulse). For example, if TMS is focused on the part of the brain that is associated with movement of the right thumb, the activated neurons cause the right thumb to twitch.
For the treatment of depression, the brain area stimulated is known as the left dorsolateral prefrontal cortex, an area on the left side of the forehead. Magnetic resonance imaging studies have shown that this area is underactive in patients with depression. By stimulating that area with TMS, the area may become more active.
“We find that when TMS treatment is given for a period of weeks, people begin to feel a difference in their mood, sleep, appetite, and ability to concentrate, and the symptoms of depression begin to resolve. It takes four to six weeks to see a complete resolution of symptoms, which is about as long as it takes for a medication to work,” explained Sarah H. Lisanby, MD, Director of the Brain Stimulation Service Line at NewYork-Presbyterian Hospital/Columbia University Medical Center. Side effects most commonly include headache and scalp discomfort.
Building on Previous Research
Building on previous findings showing the safety and efficacy of TMS in the treatment of major depression, Dr. Lisanby and colleagues investigated in a study whether some patients are more likely than others to benefit from TMS.
The research involved 301 patients with nonpsychotic unipolar major depression from 23 centers who were randomized to active or sham TMS. Active treatment consisted of TMS at the left dorsolateral prefrontal cortex (an area of the brain linked to mood) at 10 pulses per second, 120% of motor threshold, for a total of 3,000 pulses per day for four weeks. The sham (or placebo) treatment was similar to the active treatment except that the TMS coil had a shield to block the magnetic field from entering the brain.
In this study, people who had failed to respond to a single antidepressant medication before entering the study were significantly more likely to respond to TMS than those who failed two to four antidepressant medication trials. This finding, on which the FDA labeling was based, suggests that patients who do not respond to multiple medication trials may benefit from more potent treatments like electroconvulsive therapy. Unlike electroconvulsive therapy, TMS does not stimulate a large enough number of neurons to cause a seizure when given in accordance with safety guidelines.
Continued Research at NewYork-Presbyterian Hospital
Dr. Lisanby and colleagues at NewYork-Presbyterian Hospital are conducting ongoing research on TMS in the treatment of depression as well as for other uses that are not currently FDA-approved including bipolar disorder, schizophrenia, panic disorder, obsessive-compulsive disorder (OCD), Tourette’s Syndrome, depersonalization disorder, autism, and cerebral palsy. “We have a broad spectrum of studies that are using TMS and other forms of brain stimulation techniques to provide help when medications fail and for disorders that don’t have effective treatments, like autism,” Dr. Lisanby said. “What distinguishes NewYork-Presbyterian from other programs is that we conduct research that contributed to the approval of TMS in the treatment of depression and we are continuing to do studies on ways to augment the efficacy of TMS. The clinical care that we offer is evidence-based and informed by the latest cutting edge research.”