TMS results are not permanent. For most people treated for depression, the benefits of a standard course of transcranial magnetic stimulation last roughly five months before the risk of relapse begins to climb. That said, the effects aren’t fleeting either. Many patients maintain meaningful improvement for months, and repeat treatments or maintenance sessions can extend those gains considerably.
How Long TMS Results Typically Last
After completing a standard acute course of TMS (usually daily sessions over four to six weeks), responders can generally expect a stable period of symptom relief. The relapse rate stays relatively low for the first several months, then begins rising around the five-month mark, when approximately 20% of patients who initially responded see their symptoms return.
This timeline varies from person to person. Some people stay well for a year or longer without additional treatment. Others notice symptoms creeping back sooner. The key point is that TMS doesn’t work like a one-time cure. It’s more like pressing a reset button on brain activity patterns that had become stuck, and over time, those patterns can drift back without reinforcement.
Why the Effects Fade
TMS works by delivering magnetic pulses to specific areas of the brain, triggering changes in how nerve cells communicate. These changes happen through a process called synaptic plasticity: the brain strengthens or weakens connections between neurons based on the stimulation it receives. High-frequency pulses tend to boost activity in underactive regions, while low-frequency pulses calm overactive ones.
During a treatment course, repeated sessions build on each other, reinforcing new patterns of neural communication. This is similar to how practicing a skill gradually rewires the brain. The stimulation also appears to influence neurotransmitter production and gene expression at the cellular level, contributing to longer-lasting shifts in mood regulation. Some of these structural and chemical changes persist for weeks to months after treatment ends, with certain effects lasting up to 60 minutes per session and accumulating over the full course.
But the brain is constantly adapting. Without ongoing reinforcement, the strengthened connections can weaken over time, and older patterns of activity may reassert themselves. This is why depression can return even after a successful round of TMS.
What Affects How Long Results Last
Several factors influence whether someone stays well for three months or twelve. Age is one of the most consistent predictors: younger patients tend to get stronger, longer-lasting responses. As age increases, the antidepressant effect of TMS generally decreases, likely because the brain’s capacity for forming new neural connections declines with age.
Treatment history matters too. People who have tried and failed many antidepressants before turning to TMS (a pattern called high treatment resistance) tend to have shorter-lasting results than those with less treatment resistance. Gender may also play a role. Studies with strong TMS outcomes have tended to include more female patients, suggesting women may respond somewhat more favorably, though the reasons aren’t fully understood.
Taking an antidepressant medication alongside TMS appears to be a positive factor. Concurrent antidepressant use is associated with better outcomes, possibly because the medication helps maintain the neurochemical shifts that TMS initiates. Personality traits like persistence (a tendency to keep working toward goals despite frustration) have also been linked to better treatment response, though this is based on smaller studies.
Maintenance Sessions Can Extend the Benefits
Because TMS effects aren’t permanent, clinicians have developed maintenance protocols designed to preserve the initial gains. The idea is straightforward: instead of waiting for a full relapse and starting over, you receive periodic “booster” sessions to reinforce the brain changes from your original treatment course.
Maintenance approaches vary. Some involve weekly sessions for an extended period, while others use a tapering schedule that gradually spaces sessions further apart. A randomized clinical trial published in JAMA Network Open tested weekly maintenance sessions over 24 weeks following successful acute treatment. The evidence for maintenance TMS is still building, and current clinical guidelines rate it as a level 3 recommendation (meaning there’s supporting evidence, but not yet from large-scale trials).
There’s no universally agreed-upon schedule yet for how often maintenance sessions should happen or how long they should continue. Your provider will typically base the plan on how you responded initially and how quickly symptoms tend to return.
What Happens if Symptoms Come Back
One of the reassuring aspects of TMS is that it can be repeated. If you responded well to your first course but symptoms eventually return, a second round of treatment is a reasonable option. Clinically, patients who responded the first time are generally expected to respond again, which makes TMS different from some medications that lose effectiveness over time.
A re-treatment course is typically shorter than the initial one. Rather than the full four-to-six-week protocol, many providers use an abbreviated series to get you back to where you were. This is another reason the “not permanent” label isn’t as discouraging as it sounds: the door stays open for effective retreatment.
Long-Term Safety of Repeated Treatment
If you’re considering TMS as an ongoing part of managing depression, safety over the long haul is a fair concern. The data here is reassuring. The most common side effects are headache (affecting about 7% of patients) and discomfort at the stimulation site (about 3%). These are typically mild and tend to diminish over the course of treatment.
Serious adverse events are rare, occurring in roughly 1.5% of patients in studies of older adults, who are generally more vulnerable to side effects. No deaths have been attributed to TMS in any published study. The treatment doesn’t require anesthesia, doesn’t cause memory loss, and doesn’t carry the systemic side effects associated with many antidepressant medications.
What researchers still lack is large-scale data tracking patients over many years of repeated TMS courses. The existing evidence shows a stable safety profile through multiple treatment rounds, but truly long-term longitudinal studies are still limited in number.
A Realistic Expectation
Think of TMS less like a permanent fix and more like a highly effective tool that may need to be used periodically. For many people, a single course provides months of meaningful relief. For some, that relief stretches well beyond a year. When symptoms do return, maintenance sessions or retreatment can restore the benefits. The combination of strong initial efficacy, a favorable safety profile, and the ability to repeat treatment makes TMS a durable option for managing depression, even if the word “permanent” doesn’t quite apply.