Major depressive disorder (MDD) remains a global public health crisis, with treatment-resistant depression (TRD) affecting up to 30% of patients and imposing significant personal, familial, and economic burdens (Chen et al., 2023). For decades, conventional treatments like pharmacotherapy and psychotherapy have left many individuals without adequate relief. Repetitive transcranial magnetic stimulation (rTMS) has emerged as an evidence-based, non-invasive alternative, but its traditional 4–6 week schedule poses logistical challenges for patients and clinicians alike. Enter accelerated rTMS—a innovative approach that condenses treatment into days rather than weeks—offering new hope for efficiency without compromising efficacy. In this blog, we’ll explore the science, evidence, and future of accelerated rTMS, grounded in rigorous clinical research.

What Is Accelerated rTMS?

Repetitive transcranial magnetic stimulation (rTMS) uses pulsed electromagnetic fields to modulate neuronal activity in targeted brain regions, most commonly the left dorsolateral prefrontal cortex (L-DLPFC) for depression (Miron et al., 2021). Conventional rTMS typically involves 20–30 once-daily sessions over 4–6 weeks, but accelerated protocols deliver multiple sessions per day with controlled inter-session intervals (ISIs), completing the full course in days or weeks (Chen et al., 2023). This approach reduces time demands, improves clinical efficiency, and may accelerate symptom relief—critical for patients with acute distress or suicidality (Fitzgerald et al., 2018).

Two key variations of accelerated rTMS have gained traction:

• Accelerated high-frequency rTMS (aHF-rTMS): Delivers 10 Hz stimulation (the most common frequency for depression) in multiple daily sessions (Baeken et al., 2018).
• Accelerated theta-burst stimulation (aiTBS): A time-efficient form of rTMS that delivers pulses in theta-frequency bursts (5 Hz), reducing session duration to minutes while maintaining therapeutic potency (Huang et al., 2005; Chen et al., 2021).

Efficacy: Matching or Exceeding Conventional rTMS

A core question about accelerated rTMS is whether its condensed schedule sacrifices effectiveness. Clinical evidence resoundingly answers “no”—in fact, it often matches or exceeds traditional protocols.

Chen et al. (2023) conducted a comprehensive review of two decades of accelerated rTMS research, concluding that its antidepressant efficacy is comparable to once-daily rTMS. In a randomized controlled trial (RCT) of 115 TRD patients, Fitzgerald et al. (2018) found no significant differences in remission rates, response rates, or symptom reduction between accelerated rTMS (three sessions/day over 3 weeks) and conventional rTMS (one session/day over 4 weeks). Both groups received 63,000 total pulses, confirming that total dose—rather than session frequency—drives therapeutic outcomes.

For aiTBS, results are equally promising. Blumberger et al. (2021) randomized 208 TRD patients to twice-daily aiTBS (600 pulses/session) or once-daily aiTBS (1,200 pulses/session) over 30 days. Depression severity improved similarly in both groups, with response rates of 44.3% and 41.1%, respectively. Notably, aiTBS sessions last just 192 seconds, making accelerated schedules (e.g., 2–3 sessions/day) feasible for busy clinics (Chen et al., 2021).

Even more striking are results from high-dose accelerated protocols like Stanford Neuromodulation Therapy (SNT). Williams et al. (2018) reported an 83.3% response rate and 66.7% remission rate in TRD patients treated with 10 aiTBS sessions/day over 5 days (90,000 total pulses). A subsequent sham-controlled RCT confirmed SNT’s superiority: 78.6% of active treatment patients achieved remission, compared to 13.3% in the sham group (Cole et al., 2022). This protocol recently received FDA clearance for TRD, validating its clinical utility (Magnus Medical, 2022).

Safety and Tolerability: A Low-Risk Profile

Non-invasiveness and safety are hallmarks of rTMS, and accelerated protocols maintain this advantage. Chen et al. (2023) note that accelerated rTMS is “well-tolerated and not associated with serious adverse effects.” The most common side effects—scalp discomfort, transient headaches, and fatigue—are mild, temporary, and comparable to conventional rTMS (Fitzgerald et al., 2018; Miron et al., 2021).

Importantly, accelerated rTMS does not increase seizure risk—a key concern with brain stimulation. A 2022 review by Caulfield et al. (2022) found that seizure rates, adverse events, and dropout rates for accelerated rTMS are identical to once-daily schedules. Even in elderly populations, accelerated protocols are safe: a feasibility study of 10 elderly females with TRD reported a 40% response rate with no serious side effects (Dardenne et al., 2018).

Cognitive safety is another priority. Unlike electroconvulsive therapy (ECT), rTMS—including accelerated forms—does not cause cognitive impairment (Baeken et al., 2017; Chen et al., 2023). Fitzgerald et al. (2020) confirmed that aiTBS had no negative impact on cognitive performance in a pilot RCT of TRD patients.

Mechanisms: How Accelerated rTMS Works

The therapeutic effects of rTMS stem from its ability to modulate neuroplasticity—the brain’s capacity to rewire connections. Accelerated protocols may enhance this process by:

• Increasing synaptic plasticity: High-frequency stimulation (10 Hz) and TBS patterns induce long-term potentiation (LTP), strengthening synaptic connections in mood-regulating networks (Larson et al., 1986; Huang et al., 2005).
• Modulating brain connectivity: Neuroimaging studies show that accelerated rTMS normalizes functional connectivity between the DLPFC and subgenual anterior cingulate cortex (sgACC)—a region hyperactive in depression (Baeken et al., 2014; Klooster et al., 2019).
• Targeting neurochemical imbalances: Accelerated rTMS increases gamma-aminobutyric acid (GABA) concentrations in the L-DLPFC, a neurotransmitter linked to mood regulation (Baeken et al., 2017).

Notably, the timing of sessions matters. Smolen et al. (2016) found that ISIs of 60–90 minutes optimize neuroplasticity, as shorter intervals may not allow sufficient time for synaptic changes. This aligns with SNT’s 50-minute ISIs, which likely contribute to its high efficacy (Williams et al., 2018).

Who Benefits Most from Accelerated rTMS?

Accelerated rTMS is a versatile treatment, but it may be particularly valuable for:

• Patients with TRD: Those who failed 2+ antidepressant trials (the standard definition of TRD) show robust responses to accelerated protocols (Baeken et al., 2013; McGirr et al., 2015).
• Acute or high-risk patients: Individuals with suicidality, rapid physical decline, or acute distress benefit from the condensed schedule (Desmyter et al., 2016; Konstantinou et al., 2020).
• Elderly patients: Safe and effective for older adults, who may face barriers to long-term treatment (Desbeaumes Jodoin et al., 2019).
• Patients with comorbidities: Accelerated rTMS improves both depression and comorbid anxiety (McGirr et al., 2015) and may be effective for depression with psychotic features (Konstantinou et al., 2021).

The Future of Accelerated rTMS: Personalization and Optimization

While accelerated rTMS is already transformative, ongoing research aims to refine it further:

• Personalized targeting: Neuroimaging (e.g., resting-state fMRI) can identify individual-specific DLPFC regions most anti-correlated with the sgACC, improving response rates (Fox et al., 2012; Cole et al., 2020).
• Parameter optimization: Future studies will clarify optimal ISIs, pulse doses, and frequencies for different patient subgroups (Chen et al., 2023).
• Combination therapies: Pairing accelerated rTMS with psychotherapy or pharmacotherapy may enhance durability (Donse et al., 2018; Rachid et al., 2018).
• Biomarker-guided treatment: EEG and fMRI biomarkers can predict response, allowing clinicians to tailor protocols (Arns et al., 2012; Klooster et al., 2020).

Conclusion

Accelerated rTMS represents a paradigm shift in the treatment of MDD and TRD. By condensing treatment into days, it addresses logistical barriers while maintaining efficacy and safety. Clinical evidence—from small pilot studies to large RCTs—confirms that it matches or exceeds conventional rTMS, with the potential for faster symptom relief. As research advances, personalized, biomarker-guided accelerated protocols will likely become the standard of care, offering hope to millions of patients failed by traditional treatments.

If you or a loved one struggles with treatment-resistant depression, accelerated rTMS is a safe, evidence-based option worth discussing with a psychiatrist. Its ability to deliver rapid, effective relief—without the side effects of medications or cognitive risks of ECT—makes it a game-changer in mental health care.

References

1. Chen L, Klooster DCW, Tik M, et al. (2023). Accelerated Repetitive Transcranial Magnetic Stimulation to Treat Major Depression: The Past, Present and Future. Harvard Review of Psychiatry, 31(3), 142–161. PMC10188211.
2. Miron JP, Desbeaumes Jodoin V, Lesperance P, et al. (2021). Repetitive transcranial magnetic stimulation for major depressive disorder: basic principles and future directions. Therapeutic Advances in Psychopharmacology, 11, 20451253211042696. PMC8474312.
3. Garnaat SL, Yuan S, Wang H, et al. (2018). Updates on Transcranial Magnetic Stimulation Therapy for Major Depressive Disorder. Psychiatric Clinics of North America, 41(3), 419–431. PMC6979370.
4. Tang SJ, Holle J, Dadario NB, et al. (2023). Personalized, parcel‐guided rTMS for the treatment of major depressive disorder: Safety and proof of concept. Brain and Behavior, 13(11), e3268. PMC10636393.
5. Möbius M, Lacomblé L, Meyer T, et al. (2017). Repetitive transcranial magnetic stimulation modulates the impact of a negative mood induction. Social Cognitive and Affective Neuroscience, 12(4), 526–533. PMC5390712.