Randomization and blinding
Consistently trained physicians assess enrolled patients. A tDCS operator used SPSS, with a default fixed value of 2,000,000, to generate a table of random numbers. Then delivered either tDCS or sham according to a randomization list in a 1:1 ratio. Only the tDCS operators knew the grouping of each patient and revealed it to researchers after all patients had completed the last assessment. Hence, both patients and assessors are blinded to the treating conditions.