How TMS Targets Brain Circuits

Transcranial Magnetic Stimulation (TMS) is a non-invasive therapy that targets brain regions involved in mental health conditions such as depression and OCD.

At Clear Path Psychiatry, we use BrainsWay H coils, designed to provide deep, broad stimulation.

The Coils We Use at Clear Path

We use Brainsway H coils, including the H1 coil and the H7 coil:

H1 Coil: Targets both dorsolateral prefrontal cortices (DLPFCs), with a preference for the left side. The H1 coil is FDA-cleared for major depressive disorder and “anxious depression.”
H7 Coil: Targets the medial prefrontal cortex (MPFC) and anterior cingulate cortex (ACC) located in the front of the brain. The H7 coil is FDA-cleared for OCD and depressio
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These brain regions are interconnected and can be thought of as a circuit—we can selectively target distinct parts of the circuit to alleviate symptoms of depression or OCD.

How TMS Treatment Works

Your provider will assess your symptoms and determine which coil, target, and protocol are best suited to treat your depression or OCD.

The first day of treatment, your provider will perform a mapping procedure and assess your “motor threshold.”

     During the mapping, the coil will be moved around to determine the optimal spot that causes a part of your body to twitch.

After finding the best location, the intensity of the impulse is adjusted until it causes the body part to twitch 50% of the time.
      This intensity is known as your motor threshold and differs between individuals.
      (TMS is administered at an intensity related to your individual motor threshold.)
After the mapping procedure is complete and motor threshold assessed, the coil is moved to the treatment location.

Standard TMS Protocols

With once-daily TMS, most people notice benefit by the 3rd or 4th week, and improvement gradually continues through the twice-weekly phase[1]

TMS and Brain Circuits

TMS targets the dorsolateral prefrontal cortex (DLPFC), a brain region that plays a central role in mood, focus, and decision-making.
By restoring balance in this area and its connected networks, TMS can reduce rumination and improve emotional regulation.²

                          Explore the brain networks involved:

Abnormal communication among these circuits can lead to constant rumination, self-criticism, and negative focus.

The DLPFC connects to key networks implicated in depression:

• Salience network – decides what to focus on or ignore

• Default mode network – active during mind-wandering and rumination

• Executive network – guides planning, decision-making, and impulse control

The left DLPFC (LDLPFC) also connects to the limbic system—the brain’s emotional center (amygdala, hippocampus, striatum).
Stimulating the underactive LDLPFC has been consistently shown to improve depression symptoms, while in some cases, suppressing an overactive right DLPFC (RDLPFC) provides additional benefit.²

TMS and Neuroplasticity

Studies show TMS can stimulate neurons to grow new dendrites and forge stronger connections — a process called neuroplasticity.

TMS doesn’t just improve symptoms—it also promotes this neuroplasticity which is the brain’s ability to rewire and adapt.
This helps the brain adapt, regulate mood, and improve cognitive flexibility.

By encouraging new connections between brain regions involved in mood and cognition, TMS helps restore healthier communication patterns.[3]

                         Explore the science behind TMS and neuroplasticity:

Using magnetic fields to activate specific brain regions, TMS induces neuroplasticity, the brain’s natural capacity to adapt.
In the context of mental illness, this process strengthens communication between regions linked to mood regulation, cognition, and emotional processing, helping the brain build new pathways and regulate symptoms more effectively.[3]

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Appendix — Brain Areas

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ACC = anterior cingulate cortex 

DLPFC = dorsolateral prefrontal cortex 

MPFC = medial prefrontal cortex 

Ready to explore TMS therapy?

Schedule a consultation with Clear Path Psychiatry and learn how our expert team can help.

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References:

[1] - Lefaucheur J-P, Aleman A, Baeken C, Benninger DH, Brunelin J, Di Lazzaro V, Filipović SR, Grefkes C, Hasan A, Hummel FC, Jääskeläinen SK, Langguth B, Leocani L, Londero A, Nardone R, Nguyen JP, Nyffeler T, Oliveira-Maia AJ, Oliviero A, Padberg F, Palm U, Paulus W, Poulet E, Priori A, Rossi S, Rossini PM, Rothwell J, Schönfeldt-Lecuona C, Siebner HR, Slotema CW, Stagg C, Valls-Solé J, Ziemann U. Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS). Clinical Neurophysiology. 2014;125(11):2150–2206. doi:10.1016/j.clinph.2014.05.021.

[2] - U.S. Food and Drug Administration. Repetitive Transcranial Magnetic Stimulation (rTMS) Systems – Premarket Notification (510(k)) Clearances. Clinical Neurophysiology. Available at: FDA.gov.

[3] - Vaidya MV, Knudsen GM, Østergaard M, Espenhahn S, Dyrby TB, Drasbek KR. Repetitive Transcranial Magnetic Stimulation Reduces Depressive-like Behaviors, Promotes Formation of Dendritic Spines, and Strengthens Synaptic Connectivity in the Frontal Cortex and Dentate Gyrus. Translational Psychiatry. 2021;11(1):29. doi:10.1038/s41398-021-01332-3.