The design of the present study protocol is a double-blind placebo controlled randomised clinical trial.
After being randomly allocated, the experimental group will receive a 20 minutes of active 2-mA tDCS once a day on 10 consecutive weekdays. The control group will receive a sham stimulation (placebo), which chosen parameters consists in after 40 seconds of real stimulation (2 mA), only a small current pulse occurred every 550 msec (110 mA over 15 msec) through the remainder of the 20-minute period.
Neuropsychological and psychiatric assessments will be performed at the time of consent (baseline), and at 1 and 3 months following the end of the intervention (maintenance effect). The primary outcome will be cognitive function and the second outcomes will be the positive and negative symptoms. Outcome assessments will be performed by trial research staff. Primary and second outcomes assessors (neuropsychologists and psychiatrists) and patients will be blinded to randomized allocation after assignment to interventions.
