For most people suffering with major depressive disorder, treatment with medications and psychotherapy usually eases their symptoms. When symptoms do not improve, patients may be diagnosed with treatment-resistant depression.
Transcranial magnetic stimulation, or TMS, is an FDA-approved therapy used for individuals who have treatment-resistant depression.
Transcranial magnetic stimulation
TMS is a therapy option when antidepressant medications have failed or when the side effects of medications are intolerable.
TMS uses a focused electromagnet to stimulate underactive cells in a targeted area of the brain called the left dorsolateral prefrontal cortex. The magnetic pulses generate an electrical current that raises brain activity back to normal levels.
Peter Clagnaz, MD, a psychiatrist at UF Health Jacksonville and medical director of the Brain Stimulation and Treatment-Resistant Depression Program, started offering TMS as a therapy option to patients in fall 2021 at UF Health Jacksonville.
“The doctor-patient relationship is very important,” Clagnaz said. “It’s critical having a trusting, kind, authoritative person with whom you can share information and make decisions together.”
Clagnaz and UF Health Jacksonville psychiatrist Daniel Lewis, MD, have seen patients feel significant relief from their depression, and some even have full remission of their depressive symptoms after treatment.
TMS therapy process
The first therapy session for TMS typically lasts one hour, and involves two steps. First, “motor threshold determination” is completed to identify the level of electromagnetic energy needed to stimulate the patient’s brain. The psychiatrist locates a particular area of the motor cortex and delivers the right amount of energy to cause movement of the patient’s thumb.
Next, a procedure called “mapping” uses a 3D camera to pinpoint the dorsolateral prefrontal cortex — the part of the brain that is underactive in patients with depression. The threshold of energy is then delivered by the TMS device to the left dorsolateral prefrontal cortex.
After the initial hourlong session, subsequent sessions last 30 minutes and are scheduled five days per week over a six-week period. Although Clagnaz has found no cognitive side effects as a result of the brain stimulation, some reported side effects of TMS include minor scalp irritation over the stimulation area and headaches.
Qualifying for TMS
Patients with various devices, including pacemakers, defibrillators or some other metal device or foreign body located inside the head or upper chest, would not qualify for TMS.
Patients who experience seizures are also excluded, as this treatment has the potential to provoke seizures.
“There is hope for people who have not been able to achieve relief of their depression through other methods,” Clagnaz said.