Specific objectives: Of the specific objectives include the verification of the effects of repetitive transcranial electrical stimulation (5 applications) on: (1) the records of event-related potentials over 32 brain regions, (2) craving, (3) the performance of the frontal assessment battery, (4) the performance of two-back visual-spatial working memory task, (5) the performance of two-back auditory working memory task, (6) the performance of the inhibitory control behavior in a Go / No-Go task, (7) the performance of error detection, mental flexibility and inhibitory control in a counting Stroop test, (8) the quality of life.