Transcranial Direct-current Stimulation (tDCS) in Treatment Refractory Auditory Hallucinations

Inclusion Criteria: * Inpatient adults (age 18-65 years) who meet diagnostic criteria for schizophrenia or schizoaffective disorder (using the Structured Clinical Interview for DSM) * Auditory hallucinations without remission over 5 years (remission is defined as a period of 4 weeks without hallucinations) as documented in the patients' medical record * Failure to respond to two previous adequate antipsychotic trials with adequate duration and adequate dosage * Screening PANSS total rating of \> 70 * PANSS hallucinatory behavior item \> 4 * Capacity and willingness to sign informed consent * On a stable antipsychotic regimen 4 weeks prior to screening and for the duration of the trial * Normal hearing * If female and not infertile, must agree to use one of the following forms of contraception for the duration of study participation: systemic hormonal treatment, an interuterine device (IUD) which was implanted at least 2 months prior to screening, or "double-barrier" contraception * Willing to wear the tDCS device. Exclusion Criteria: * Prior history of seizure, other than that induced by Electro Convulsive Therapy * Family history of seizures * Significant unstable medical condition * Pregnancy or women of childbearing capacity not using a medically accepted form of contraception when engaged in sexual intercourse * Inability to provide informed consent * Actively suicidal and or showing violent behavior * Significant organic brain pathology by history and neurological examination, inclusive of history of head trauma, loss of consciousness for more than 5 minutes; intracranial metal implants, known structural brain lesion, devices that may be affected by transcranial Direct Current Stimulation (tDCS) (pacemaker, medication pump, cochlear implant, implanted brain stimulator) * Active substance abuse * Increased intracranial pressure, unstable cardiovascular disease, sleep apnea * Individuals with a clinically defined neurological disorder * Frequent and persistent migraines * History of adverse reaction to neurostimulation or open skin wounds that would preclude safe placement of tDCS electrodes * Current use of medications known to lower seizure threshold (serotonergic or tricyclic antidepressants) * If pregnant or breast feeding at the time of screening