Statistics.
HDRS21
The full statistical plan is presented in For sample size estimation, a noninferiority margin of 3 points (δ = 3) between the changes in HDRS-21 for the 2 treatment arms was chosen, as this is considered the threshold for a difference between treatments to be clinically meaningful (Baseline demographics and clinical characteristics were compared between the study groups. For comparison of means (continuous variables), the 2-sample Details regarding rationale, hypotheses, recording, preprocessing, and statistical methods for EEG are described in the Two-second epochs, starting 1 second following trains’ ending (to avoid TMS-related artifacts induced by the stimulation), were extracted from the intertrain intervals of the treatment data. Additionally, 1-second epochs immediately adjacent to trains’ commencing were extracted for noise reduction purposes. Power spectral density was then computed using Welch’s method, and influence of transient noise was reduced by train-wise deviation of the posttrain activity power spectrum with that of pretrain activity. Spectral density was computed using 2 reference schemes: AVR and CSD used to investigate the possibility that prefrontal activity may originate from posterior sources (Next, absolute activity power in the alpha (8–12 Hz) and low-gamma (30–40 Hz) bands was extracted, and asymmetric activity scores were calculated as ratio between activity power of each electrode and that of the homologous electrode in the counter hemisphere. Alpha, low-gamma, and low-gamma/alpha ratio of activity and asymmetry scores were then linearly correlated with improvement percentage in HDRS21 score following 6 weeks of treatment. Site was partialled out of the correlation to control for site-related variability due to electrophysiological noise (multiple amplifiers, EEG caps, EEG technicians) and possible differences in rating tendencies. Correlations were further stabilized, by removing observations deviating more than 3 SDs from the mean of residual scores or leveraging scores. Following a priori hypotheses, groups were tested for differences in correlation magnitudes using Fisher’s 