How Accelerated iTBS Depression Protocols Are Changing TMS Care
Accelerated iTBS depression protocols are reshaping how clinicians think about transcranial magnetic stimulation for major depressive disorder. Traditional TMS is delivered once daily over several weeks. Accelerated intermittent theta burst stimulation compresses that timeline into multiple daily sessions over just a few days, dramatically shortening treatment while maintaining strong antidepressant effects.
The Stanford Neuromodulation Therapy approach helped popularize accelerated iTBS by showing that high dose, carefully targeted stimulation could produce rapid symptom relief in treatment resistant depression. What has remained less clear is how the brain responds during each session and across days when stimulation is delivered at such an intense pace. Understanding those dynamics matters for safety, durability of benefit, and future personalization of care.
Using fNIRS To Track Brain Changes During Accelerated iTBS Depression
A recent open access study addressed this gap by pairing accelerated iTBS with functional near infrared spectroscopy, or fNIRS. Unlike MRI or EEG, fNIRS can be used during stimulation, allowing researchers to track real time changes in blood oxygenation in the prefrontal cortex as treatment unfolds.
The study followed a patient with major depressive disorder who received 50 iTBS sessions over five days, targeting the left dorsolateral prefrontal cortex using neuronavigation. fNIRS measured oxygenated and deoxygenated hemoglobin before, during, and after every session. Depression severity and side effects were tracked daily.
Clinically, the patient experienced a meaningful short term reduction in depressive symptoms with tolerable side effects. Although symptoms partially returned within two weeks, the case offered a rare window into how accelerated iTBS depression protocols affect brain physiology moment by moment.
What The Hemodynamic Signals Reveal About Brain Excitability
The fNIRS data showed clear and consistent changes in both the stimulated and opposite sides of the prefrontal cortex. During and after iTBS sessions, markers of cortical activation increased, suggesting heightened excitability and engagement of mood related networks.
Importantly, these responses evolved over time. As sessions accumulated, the size of the hemodynamic response gradually decreased. This pattern likely reflects neural efficiency and homeostatic plasticity, where the brain becomes more stable and less reactive as circuits adapt to repeated stimulation.
The study also found substantial variability between sessions early in treatment, which steadily declined across days. This mirrors what clinicians often observe in practice and highlights how brain state, anatomy, and stimulation parameters interact during accelerated iTBS depression treatment.
Why These Findings Matter For Precision TMS
Real time monitoring offers more than academic insight. If early brain responses predict clinical outcomes, tools like fNIRS could eventually help clinicians adjust stimulation dose, spacing, or targeting in near real time. That would move TMS closer to truly personalized psychiatry.
The findings also reinforce the importance of accurate targeting. Differences from earlier Stanford protocols, such as using standardized coordinates instead of connectivity guided targets, may have influenced durability of response. Combining accelerated iTBS depression protocols with individualized targeting and physiological monitoring may improve long term outcomes.
Looking Ahead For Accelerated ITBS Depression Research
While this was a single case, it demonstrates the feasibility and value of combining accelerated iTBS with real time brain monitoring. Larger controlled studies are needed to confirm these patterns and determine whether early hemodynamic changes can reliably predict who will benefit most.
As accelerated iTBS depression protocols continue to spread, understanding how the brain adapts across sessions will be essential. Tools like fNIRS may help clinicians move from one size fits all stimulation toward data guided, adaptive neuromodulation that maximizes benefit while minimizing burden for patients.
Citations
- Xia A W et al. Temporal Variation of Brain Hemodynamics with Accelerated iTBS for Depression A Single Case Concurrent TMS fNIRS Study. Brain Stimulation. 2025. https://doi.org/10.1016/j.brs.2025.103020
- Cole E J et al. Stanford Accelerated Intelligent Neuromodulation Therapy for Treatment Resistant Depression. American Journal of Psychiatry. 2020. https://doi.org/10.1176/appi.ajp.2019.19070720