Randomized Controlled Trial of Pyridoxine for Tardive Dyskinesia

Inclusion Criteria: * Meet Schooler - Kane criteria for TD (at least one muscle group is rated at "moderate" severity or at least two muscle groups are rated at "mild" severity). * Subjects must have \> or equal to 3 months of antipsychotic exposure. * Other causes of involuntary movements have been ruled out. * Psychiatrically stable as defined by outpatient status for \> or equal to 2 months. * No change in dopamine antagonist agent or dose for \> or equal to 2 months or change in other prescribed medications for \> or equal to 1 month prior to enrollment * Patients must be 18-80 years of age. * Patients must demonstrate adequate decisional capacity to make a choice about participating in this research study and must provide written informed consent to participate. * Women who can become pregnant must be using an adequate method of contraception to avoid pregnancy throughout the study. Acceptable methods include oral, injectable or implanted contraceptives, intrauterine devices or barrier methods such as condoms, diaphragm and spermicides. Women who can become pregnant must have a negative serum beta human chorionic gonadotropin (β-HCG) pregnancy test at the Screening Visit. Exclusion Criteria: * Inpatient status * Clinical Global Impression Severity (CGI-S) score \> or equal to 6. * Evidence of any medical condition(s) that could confound the presence of TD. * Currently taking more than 2 antipsychotic medications. * Currently taking levodopa. * Current or prior treatme…