Secondary outcomes
Global functioning was measured using the CGI-S (Clinical Global Impression–Severity) scale [RS-EEG. The full details on the EEG recording and pre-processing are given in Supplementary Material Pre-processing of EEG data. EEG data was analysed using EEGLAB software [A fast Fourier transform (FFT) was used to calculate the absolute power spectra within different specific frequency bands, focusing on delta (0.5–2 Hz), theta (34–7 Hz), alpha (8–13 Hz), beta (13–30 Hz), and total power (1–40 Hz) of all band changes in each group. Here, we focused on analysing the data from electrodes over the stimulation sites (F3, F8) as well as from frontal midline area (Fz), which has been shown changes in aperiodic exponent following tRNS applied to similar brain regions [We then employed a spectral parameterization approach which enables decomposition of the neural signal into its respective periodic and aperiodic components, with a tool called FOOOF (fitting oscillations and one over 