The purpose of this study is to test the impact of non-invasive brain stimulation, transcranial direct current stimulation (tDCS), on auditory hallucinations, negative symptoms and cognition in schizophrenia. Clinical measures will be used to assess clinical symptoms and cognitive performance to test the hypothesis that a course of tDCS can reduce auditory hallucinations and negative symptoms in schizophrenia.

Inclusion Criteria:

• Participants must be able to sufficiently speak and understand English so as to be able to understand and complete cognitive tasks.
• All subjects must have the ability to give valid informed consent.
• No children under the age of 18 will be recruited.
• Diagnosis of schizophrenia, schizophreniform, or schizoaffective disorder
• Stable outpatient or partial hospital status
• Normal IQ (>70; IQ will be measured by administering the Wechsler Abbreviated Scale of Intelligence (WASI) test)

Exclusion Criteria:

• Pacemakers
• Implanted electrical (brain and spinal) stimulators
• Implanted defibrillator
• Metallic implants
• Skin damage or skin conditions such as eczema at the sites where electrodes will be placed
• Hair styles hindering the placement of electrodes
• Cranial pathologies
• Head trauma
• Epilepsy
• Mental retardation
• Any known history of neurological disorders (including epilepsy, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), stroke, cerebral palsy, any DSM-5 axis I psychiatric disorder (for healthy control subjects), autism)
• Uncorrected vision problems that would hinder cognitive testing (this also pertains to subjects with color blindness in tasks where discriminating colored objects/items is necessary for successful performance)
• Pregnancy
• Substance dependence in the past six months
• Substance abuse in the past month

Select data from this study may be submitted to the National Institute of Mental Health Data Archive (NDA). NDA is a data repository run by the National Institute of Mental Health (NIMH) that allows researchers studying mental illness to collect and share de-identified information with each other. The data repository is accessible only to qualified investigators. All subject data will be de-identified (subject names will not be used) and each subject will have a separate identifier called a Global Unique Identifier (GUID) to remove any possibility that "the identities of the subjects cannot be readily ascertained or otherwise associated with the data by the repository staff or secondary data users." (45 CFR, 46.102).