Transcranial Magnetic Stimulation (TMS) is a non-invasive procedure that uses magnetic fields to stimulate nerve cells in the brain, primarily to improve symptoms of major depressive disorder. The therapy works by targeting specific regions, such as those often underactive in people with depression. Understanding the time commitment involved is a common concern, as TMS requires a daily commitment over several weeks. The duration of each session and the total timeline are important factors when planning treatment.
Defining the Standard Session Length
The duration of a typical TMS treatment session is standardized for the most common protocols used for depression. Standard repetitive TMS (rTMS) sessions are scheduled to last between 20 and 40 minutes. This range is based on protocol parameters approved by the U.S. Food and Drug Administration (FDA) and used in clinical trials.
The time spent delivering the magnetic pulses is specific to the protocol. A common protocol involves delivering about 3,000 pulses, which takes approximately 37 to 40 minutes of stimulation time. This stimulation is delivered while the patient is awake and seated comfortably, requiring no anesthesia or sedation.
Factors Influencing Session Time
Session duration is affected by the specific treatment protocol selected. The traditional rTMS protocol (20 to 40 minutes) is often contrasted with newer, faster methods. Intermittent Theta Burst Stimulation (iTBS) delivers magnetic pulses in short, high-frequency bursts that mimic natural brain rhythms.
This technique reduces the stimulation time needed, with some iTBS sessions lasting as little as three minutes. The shorter duration of iTBS can make the treatment more convenient and easier to integrate into a patient’s daily schedule.
The first appointment is an exception to the standard daily session length because it is significantly longer. This initial visit requires motor threshold mapping, where the precise location and optimal intensity for stimulation are determined. This mapping involves locating the motor cortex and finding the minimum magnetic pulse strength needed to cause a slight twitch in the hand. This setup and customization process adds an extra 20 to 60 minutes, making the first session last up to 90 minutes in total.
The Complete Treatment Timeline
While individual session times vary, the overall treatment timeline for a full course of TMS therapy is consistent. The standard course for major depressive disorder requires 20 to 36 sessions. These sessions are administered daily, five days a week, typically Monday through Friday.
This schedule means the full course of treatment spans four to six weeks. Patients often begin to notice improvements in their mood or energy levels around the second to fourth week, with the full benefits appearing closer to the end of the six-week period.
After the initial course is completed, the treating physician assesses the patient’s response and determines next steps. Some individuals may require a gradual tapering of sessions or periodic maintenance sessions to sustain improvement. The overall timeline is based on clinical trial data and FDA guidelines, but the physician can adjust the total number of sessions based on the individual’s clinical progress.