Transcranial magnetic stimulation (TMS) is a noninvasive procedure that uses magnetic fields to stimulate the brain. It’s often used for treatment-resistant major depressive disorder. Unlike medication, TMS does not travel through the bloodstream, and it does not require anesthesia or sedation. Here is some information about how TMS therapy works:
Generates a Magnetic Pulse
Each TMS session uses a device with an electromagnetic coil, and the coil delivers magnetic pulses to the brain. Before your first treatment, a clinician measures your motor threshold. This is the lowest energy level that causes a small twitch in your thumb or fingers when the coil is placed over the motor area of the brain. The measurement sets the pulse strength for your treatment plan.
Once the settings are in place, the coil rests against your scalp, usually over the left prefrontal cortex. This region sits near the front of the head and helps regulate mood and decision-making. When electrical current passes through the coil, it produces a brief magnetic field. The field is similar in strength to the one used in an MRI machine, but it lasts only a second and targets a small area.
Stimulates Neurons
The magnetic field passes through the skull without resistance. It reaches a few centimeters into the brain, which affects the outer layer of the cortex. As the field moves through this tissue, it creates a small electrical current; this process is called electromagnetic induction.
Neurons communicate using electrical signals, and these signals carry information throughout the nervous system. When the induced current reaches them, the cells depolarize and fire. Repeated pulses delivered in rapid sequence prompt groups of neurons in the targeted area to activate together. This synchronized activity may strengthen connections between neurons.
The frequency of the pulses matters in TMS therapy. High-frequency stimulation tends to increase activity in the targeted region, and low-frequency stimulation decreases it. Your provider selects the frequency based on your diagnosis, and the treatment plan may be adjusted based on your response.
Normalizes Circuits
Brain regions do not work in isolation. The prefrontal cortex connects to deeper structures, which play a role in emotional processing. In many people with depression, there’s lower activity in the left prefrontal cortex and altered communication between these connected areas. TMS aims to adjust this pattern over time. A single session produces only short-term changes, so a typical course includes multiple sessions per week for several weeks. Repeated stimulation may encourage neuroplasticity, which is the brain’s ability to strengthen or reorganize connections between neurons. As the targeted region becomes more active, the effects should extend along linked networks.
Learn More About TMS Therapy
TMS therapy works through three connected steps: a coil generates a magnetic pulse, the pulse stimulates neurons, and repeated sessions influence brain circuit activity. Whether it is a suitable option depends on your current symptoms and past treatments. A qualified provider reviews these details during an evaluation, and they recommend a tailored treatment plan. Contact a mental health clinic today to schedule a consultation.
