A Symptom-Specific Analysis of the Effect of High-Frequency Left or Low-Frequency Right Transcranial Magnetic Stimulation over the Dorsolateral Prefrontal Cortex in Major Depression

Abstract

Background: We have investigated the efficacy of high-frequency left (HFL) versus low-frequency right (LFR) repetitive transcranial magnetic stimulation (rTMS) in depression, focusing on specific symptoms as possible predictors of outcome for these two different types of stimulation. Method: Seventy-four outpatients with a major depressive episode treated with an adequate antidepressant dosage for at least 4 weeks were included in our study and randomly assigned to two different groups: HFL or LFR rTMS. The Hamilton Rating Scale for Depression (HAM-D) items were pooled into 6 factors to evaluate specific symptoms as possible predictors of response. Results: Twenty-one out of 32 patients (65.6%) and 24 out of 42 patients (57.1%) were responders in the HFL and LFR groups, respectively. No significant difference in response rate was observed. Considering the whole sample, we found an inverse correlation between activity and HAM-D score reduction and a significant positive relation between somatic anxiety and outcome. An inverse correlation between psychic anxiety and HAM-D score reduction emerged considering the HFL group. In the LFR group, there was a significant negative relationship between baseline activity and the outcome. Conclusion: These findings support the hypothesis that LFR rTMS could be as effective as HFL rTMS and more suitable for patients with a higher anxiety degree, particularly in bipolar patients.

A systematic review and meta-analysis on the efficacy and acceptability of bilateral repetitive transcranial magnetic stimulation (rTMS) for treating major depression

“…The combination of HF-rTMS and LF-rTMS could potentially enhance treatment response in MD in a number of ways. For example, it is possible that some patients have left-side treatment-responsive MD and some have right-side treatment-responsive MD (Rossini et al 2010). Therefore, it is conceivable that offering both treatments to all patients can maximize the likelihood of clinical improvement in any individual patient.…”

Unilateral and bilateral MRI-targeted repetitive transcranial magnetic stimulation for treatment-resistant depression: a randomized controlled study

“…13 Studies comparing HFL-rTMS and LFR-rTMS have found equivalent response rates with the 2 treatments. [14][15][16] Thus, combining these 2 treatments may result in…”

Efficacy and Safety of Low-field Synchronized Transcranial Magnetic Stimulation (sTMS) for Treatment of Major Depression

“…rTMS is administered using a high-field (w1.5 T) electromagnet, with the best established protocols targeting the left dorsolateral prefrontal cortex (DLPFC) at frequencies of 10e20 Hz [2,4], or the right DLPFC at a frequency of 1 Hz [8,9]. The optimal intensity, brain area, and frequency of stimulation have not been established through controlled studies [10].…”