Theta-Patterned, Frequency-Modulated Priming Stimulation Enhances Low-Frequency, Right Prefrontal Cortex Repetitive Transcranial Magnetic Stimulation (rTMS) in Depression: A Randomized, Sham-Controlled Study

Efficacy of repetitive, transcranial magnetic stimulation (rTMS) has been found in depression; however, doubt still remains about its effectiveness in clinical practice. In this context, results are being explored. The authors, describing new techniques to improve response rates to rTMS treatment, compared the efficacy of adjuvant, frequency-modulated, active-priming rTMS with sham-priming stimulation in the theta range in patients with moderate-to-severe depression receiving low-frequency rTMS. Forty patients with moderate-to-severe depression (ICD–10 DCR) were alternately assigned to receive add-on, active-priming rTMS (4–8 Hz; 400 pulses, at 90% of motor threshold [MT]) or sham-priming stimulation followed by low-frequency rTMS (1-Hz; 900 pulses at 110% of MT) over the right dorsolateral prefrontal cortex. They were rated with the Structured Interview Guide for the Hamilton Depression Rating Scale (SIGH–D), the Brief Psychiatric Rating Scale (BPRS), and the Clinical Global Impression–Severity of Illness (CGI–S) scale at baseline, after the 5th and 10th rTMS, and 2 weeks post-rTMS. For SIGH–D scores, there was significant improvement in the active group over time. Stepwise linear-regression analysis showed that age at onset significantly predicted SIGH–D scores after the 5th rTMS session in the active-priming group. Pre-stimulation with frequency-modulated priming stimulation in the theta range has greater antidepressant effect than low-frequency stimulation alone.