TDCS for Auditory Hallucinations in Schizophrenia

90 patients with persistent auditory verbal hallucinations will be recruited to this study. Each individual will participate in behavioral assessments lasting up to 3 hours each and will then be randomized to receive a series of active vs. sham tDCS treatments. For active treatment, patients will have the inhibitory (cathodal) tDCS electrode placed over left auditory cortex relative to an anodal placed over frontal cortex on the right side. tDCS treatments will take place for 20 min per day for 5 consecutive days. For sham, procedures will be similar except that sham (inactive) tDCS treatment will be used. Assessment batteries will then be repeated following completion of treatment and at 1 and 3 mo following treatment. In addition, patients will be offered the possibility to participate in a concurrent magnetic resonance imaging (MRI) study aimed at evaluating the effects of tDCS on activation of auditory cortex during an auditory discrimination task as well as on other imaging parameters related to resting brain activity and metabolism. Patients who agree to participate in this MRI study will be scanned before and after active or sham tDCS. In addition, 5-15 schizophrenia patients will complete a week of High-density, e.g., "high-definition" tDCS (HD-tDCS) open label. In addition to hallucinating patients, we will recruit up to 20 healthy controls and 20 non-hallucinating patients, who will have similar assessments to the patients, but will not receive tDCS. Overall, the investigators hypothesize that tDCS treatment will lead to reduction in hallucinations, improvement in auditory function, and change in EEG and MRI measurements so that patients more closely resemble healthy volunteers and non-hallucinating patients.