Randomization and blinding.
DISEASE
Patients were stratified per center by severity of disease as determined by baseline HDRS-21 score and the antidepressant treatment history form (ATHF). Thereafter, patients who met the eligibility criteria were equally allocated (with a 1:1 ratio) to 1 of the 2 treatment groups, stratified by HDRS-21 scores (20–25 vs. ≥ 26), ATHF categories (ATHF ≥ 2 level 1–2 and ATHF 1 level 3 or higher vs. ATHF 2–4, level 3 or higher), and center, based on a random-number generator.Patients were told that they would receive 1 of 2 active treatments that differ in their parameters. The operator administering the treatment was the only one of the study personnel who was aware of the assigned group by code (A vs. B, as detailed below), while other study personnel and patients were completely blinded to the treatment being administered.