This study is a randomized, double-blind, sham-controlled clinical trial. 60 patients with TD were randomly allocated to active (n=30) or sham tDCS groups (n=30). All patients received 2-mA anodal left/cathodal right prefrontal tDCS treatment (fifteen 30-minutes sessions: Monday to Friday once daily, every other week to do a group of treatment). Abnormal Involuntary Movements Scale (AIMS), Tardive Dyskinesia Rating Scale (TDRS), Assessment of Negative Symptoms(SANS), the Positive and Negative symptom scale(PANSS), and the Cambridge Neuropsychological Test Automatic Battery (CANTAB) were assessed in patients. All evaluations were scored at baseline, the end of 3rd weeks, 5th weeks, and 7th weeks. Side effects of tDCS were assessed with an experimenter-administered open-ended questionnaire during the whole experiment.
