A study published in the Journal of Neuropsychiatry and Clinical Neurosciences in Advance has found that a patient’s response to rTMS the first time may predict how well he or she will respond to a subsequent session of rTMS. The study authors noted these findings support the use of rTMS reintroduction therapy for responders, which could potentially reduce the number of sessions that they might have otherwise received as part of maintenance therapy.
The findings arose from a retrospective chart review of 225 patients who received rTMS for treatment-resistant depression as a part of the clinical program at the Berenson-Allen Center or Noninvasive Brain Stimulation at Harvard Medical School from 2000 to 2015. Of this group, 18 patients met the criterion of having a reintroduction of TMS therapeutic strategy, though two were excluded for inadequate symptom data.
Ten of the 16 remaining patients were responders to the initial rTMS treatment (classified as at least a 50% reduction in Beck Depression Inventory [BDI] score), and eight of these 10 responders were also responders to reintroduction. Three patients who partially responded to the initial rTMS treatment (25-50% reduction in BDI) also responded to reintroduction rTMS.
There was also some correlation in the overall strength of response between sessions; that is, patients who had a strong improvement in depression symptoms after the initial session tended to have greater BDI reductions after the reintroduction session as well. The authors estimated that the magnitude of the initial response explains approximately one-third of the magnitude of subsequent response.
“Thus, other factors, either not evaluated in this study or requiring a larger sample size to achieve significance, such as gender, age, refractoriness, baseline severity, and comorbid disorders, could also have a significant predictive role,” they wrote. Nonetheless, the authors noted that the findings support “an approach involving watchful waiting and reintroduction of TMS when [responders] experience a relapse, thus placing rTMS as a viable long-term treatment regimen for treatment-resistant depression.”
For related information, see the Psychiatric News column “Neuromodulation May Benefit Patients With Varying Psychiatric Illnesses,” by Andrew Leuchter, M.D., director of the Neuromodulation Division at the Semel Institute for Neuroscience and Human Behavior at the Semel Institute for Neuroscience and Human Behavior at the David Geffen School of Medicine at the University of California, Los Angeles.