How TMS Works: A Patient-Friendly Guide to Neuroplasticity.

If you're considering TMS for depression, you may already know the basics: a device delivers magnetic pulses to a specific area of the brain, treatment happens while you're awake, and there is no anesthesia or medication involved in the procedure itself.

But that leaves a bigger question: How can magnetic pulses actually change the way you feel?

The answer may have a lot to do with one of the brain's most remarkable abilities: neuroplasticity.

Neuroplasticity is the brain's ability to change how its cells communicate and how its networks function in response to repeated activity and experience. TMS appears to take advantage of this natural capacity for change by repeatedly stimulating brain circuits involved in depression.

The science is still evolving, and researchers don't yet have a single complete explanation for why TMS improves depression in some people. But decades of research are giving us an increasingly detailed picture of what happens when the brain receives repeated magnetic stimulation.

Here's the patient-friendly version.

First, What Is TMS?

Transcranial magnetic stimulation, or TMS, is a noninvasive form of brain stimulation.

During treatment, a small electromagnetic coil is positioned against the scalp. Very brief magnetic pulses pass through the skull and create a small electrical current in the brain tissue underneath the coil. That electrical current can activate nerve cells in the targeted area.

The magnetic field produced by a TMS pulse can reach roughly the same general range of field strength as a clinical MRI—around 1.5 Tesla in some systems—but the technologies use magnetism very differently. TMS delivers extremely brief, changing magnetic pulses to stimulate a targeted part of the brain.

There is:

• No incision

• No implanted device

• No anesthesia

• No medication administered as part of the treatment

• No sedation

You remain awake throughout the session and can generally return to normal activities afterward. So where does neuroplasticity enter the picture?

What Is Neuroplasticity?

Your brain contains billions of nerve cells called neurons. Those neurons don't function independently. They communicate through enormous networks, passing signals from one cell to another across connection points called synapses. And those connections aren't fixed, your brain is continuously adjusting them.

When you learn a skill, create a memory, practice a piece of music, adapt to a new environment, or recover function after certain kinds of injury, your nervous system changes in response to experience. That ability to change is called neuroplasticity.

At the level of individual synapses, repeatedly using a connection can alter how effectively one neuron communicates with another. One of the best-studied examples is long-term potentiation, or LTP, in which repeated activity produces a longer-lasting increase in the strength of communication between neurons. The opposite process, long-term depression or LTD, can weaken particular connections.

These forms of synaptic plasticity are fundamental to learning and memory and remain an active area of neuroscience research. The simplest way to picture it is to imagine paths through a forest. A path you walk every day becomes defined and easy to follow. A path nobody uses gradually becomes harder to find. The brain isn't literally carving paths through tissue, but its networks can become more or less likely to follow particular patterns of activity depending on how those networks are used.

What Does Neuroplasticity Have to Do With Depression?

Depression isn't located in one single "depression spot" in the brain.

Instead, researchers increasingly understand it as involving networks of interconnected brain regions involved in mood, reward, attention, emotional regulation, motivation and other functions.

Some of those networks appear to function differently in people experiencing depression.

That's important because TMS doesn't have to directly reach every part of a mood network to influence it.

For depression treatment, TMS is commonly directed toward an area near the front of the brain called the dorsolateral prefrontal cortex, or DLPFC. That surface region is connected to deeper areas involved in mood and emotion.

NIMH-supported research has demonstrated that stimulating an accessible area of the prefrontal cortex with TMS can affect activity in deeper connected regions, including the subgenual anterior cingulate cortex, a region strongly implicated in depression. Researchers have also found relationships between changes in this circuit and improvement in depression symptoms.

In other words: TMS targets a specific location, but its effects can travel through a network.

How TMS May Harness Neuroplasticity

Here's one way to understand what researchers think may be happening.

1. A magnetic pulse activates nerve cells

When the TMS coil generates a rapidly changing magnetic field, that field induces a small electrical current in the brain tissue beneath it. That current can cause nearby neurons or their axons to activate. Think of each pulse as a brief nudge to a particular part of a brain circuit. A single pulse can temporarily change neural activity. But therapeutic TMS doesn't deliver just one pulse. It delivers carefully designed patterns of them.

2. Repetition begins to change how the circuit responds

When stimulation is repeated, the effects can last beyond the individual pulse itself. Research suggests that certain forms of repetitive TMS can produce changes in cortical excitability resembling the processes neuroscientists call LTP-like and LTD-like plasticity. In other words, repeated stimulation may make some neural connections more responsive and others less responsive. This is where the forest-path analogy becomes helpful. One TMS pulse is like walking down a path once. Repeated stimulation is more like traveling that route again and again. Over time, the circuit may become more capable of operating in a different pattern.

Importantly, scientists use the term "LTP-like" deliberately. Human TMS research supports changes consistent with synaptic plasticity, but researchers are still working out exactly how those processes translate from individual cells to improvements in depression.

3. The effect doesn't stop at the spot being stimulated

The brain works as a network. When TMS activates neurons in the targeted region, those neurons communicate with other areas to which they're connected. A useful analogy is a transportation system. If you improve the function of one important hub, you can change traffic throughout the network—not just at that station. NIMH researchers have demonstrated this principle directly: although TMS primarily stimulates the outer layers of the brain, its effects can influence deeper brain regions through the connections between them. This network effect is particularly relevant to depression because mood regulation involves multiple interconnected regions rather than one isolated area.

4. Repeated treatment may encourage longer-lasting changes

This is one of the most interesting—and still actively researched—parts of TMS. Laboratory research suggests that repeated magnetic stimulation can affect processes involved in synaptic strength, neurotransmission, inhibitory and excitatory signaling, and other mechanisms associated with plasticity. Animal and cellular studies have also observed changes involving dendritic spines and other structures through which neurons communicate.

In humans, brain-imaging and neurophysiology studies show that TMS can change activity and connectivity within brain networks, including networks involved in depression. It would be an oversimplification to say that scientists have watched TMS simply "rewire the brain." A better description is: Repeated TMS appears capable of shifting how neurons and brain networks communicate, and neuroplasticity is thought to be an important part of how those changes can outlast an individual treatment session.

Why Doesn't One TMS Session Fix Depression?

If the goal involves creating lasting changes in the way a brain circuit functions, repetition makes sense. Think about going to the gym. One workout can activate a muscle, but it doesn't create lasting strength. Or think about learning the piano. Playing a scale once won't make the movement automatic. Practicing repeatedly allows the nervous system to become increasingly efficient at performing it. TMS follows a similar principle.

Each treatment exposes the targeted circuit to another pattern of stimulation. Over repeated sessions, those effects can accumulate. That is one reason standard TMS treatment for depression has traditionally been delivered on weekdays over a period of several weeks. Newer approaches, including theta-burst and accelerated protocols, can deliver stimulation in different patterns and on different schedules, but repetition remains central to the treatment.

And clinically, improvement often isn't instantaneous. Some people notice changes within the first couple of weeks, while for others improvement emerges later in the treatment course.

What Might Neuroplasticity Feel Like?

You don't feel your synapses changing. There isn't necessarily a moment when your brain suddenly "switches" from depressed to not depressed. For some patients who respond to treatment, change may appear more gradually. You might notice that:

• Getting out of bed feels a little easier.

• You start answering texts again.

• Something that normally feels overwhelming feels manageable.

• Music sounds interesting again.

• You find yourself wanting to go somewhere.

• You realize you laughed without forcing it.

• Your concentration improves.

• You feel more like participating in your own life.

Those experiences don't prove that a particular synapse or network has changed, of course. They're examples of the kinds of functional changes that matter when clinicians assess whether depression treatment is helping.

What Does TMS Feel Like While It's Happening?

The neuroscience may sound complicated. The treatment itself is comparatively straightforward. You'll sit in a treatment chair while the TMS coil is positioned against your scalp. During the pulses, you'll generally hear clicking and feel a tapping sensation on the scalp. Hearing protection is typically provided because of the sound generated by the device. You're awake throughout treatment. There is no psychedelic or altered state associated with TMS. And because there's no anesthesia or sedation, most patients can drive themselves and continue with their normal day after the session. Treatment schedules vary depending on the protocol prescribed. Traditional courses are often delivered five days per week for several weeks, while some newer protocols use much shorter sessions or multiple sessions in a day.

So, Does TMS Really “Rewire” Your Brain?

You'll sometimes hear TMS described that way. It's an appealing shorthand, but neuroscience is more nuanced. There is good evidence that repetitive TMS can change brain activity, influence connected networks and produce effects that continue after stimulation ends. Research also supports LTP-like and other plasticity-related mechanisms as part of that process.

What scientists are still determining is precisely how changes at the cellular, synaptic and network levels combine to create lasting symptom improvement—and why one person's brain may respond differently from another's. A comprehensive 2025 consensus review* endorsed by major TMS and clinical neurophysiology organizations describes rTMS as a safe and effective treatment for depressive disorders while also noting that research continues into ways of enhancing its effects through targeting and neuroplasticity. So instead of thinking of TMS as mechanically "rewiring" a broken brain, it may be more useful to think of it as giving targeted brain networks repeated stimulation that can help change how they function and communicate.

And your brain does the changing.

Three Questions to Ask Your TMS Care Team

If you're considering treatment, understanding the science is helpful—but understanding your treatment plan matters even more. Ask your care team:

How many sessions will my treatment plan involve?
Different TMS protocols use different stimulation patterns and treatment schedules.

How soon might I notice a difference?
Response varies. Improvement can emerge gradually, and your treatment team should track symptoms throughout the course.

What results are realistic for my condition?
No treatment works for everyone. Your clinician can help put the research into the context of your diagnosis, previous treatments, health history and goals.

Exploring TMS in Santa Fe

At Anew TMS in Santa Fe, we believe understanding why you're receiving a treatment should be part of receiving it.

TMS involves sophisticated neuroscience, but the basic idea is surprisingly intuitive:

The brain can change. Repeated activity helps shape that change. TMS gives us a way to stimulate specific brain circuits deliberately and noninvasively.

For people whose depression hasn't improved enough with medication or psychotherapy, that creates another evidence-based avenue to explore.

If you're in Santa Fe, Albuquerque, or elsewhere in New Mexico and want to learn whether TMS might be appropriate for you, start with Is TMS Right for Me? or explore Your Patient Journey to see how treatment works at Anew.

You can also [schedule a consultation with Anew TMS] to discuss your treatment history and whether TMS belongs among the options you consider next.

This article is intended for general educational purposes and does not replace individualized medical advice, diagnosis, or treatment from a qualified healthcare professional.

*Trapp, N. T., Purgianto, A., Taylor, J. J., et al. (2025). Consensus review and considerations on TMS to treat depression: A comprehensive update endorsed by the National Network of Depression Centers, the Clinical TMS Society, and the International Federation of Clinical Neurophysiology. Clinical Neurophysiology, 170, 206–233. https://doi.org/10.1016/j.clinph.2024.12.015