Previous studies found that some NMDA-enhancing agent was able to augment antioxidant
activity and its adjunctive therapy was better than placebo in reducing clinical symptoms and
cognitive deficits and revealed favorable safety in patients with chronic schizophrenia. Of
note, a substantial portion of schizophrenia patients refuse or cannot tolerate
antipsychotics due to poor response or severe side effects. Therefore, this study aims to
examine the efficacy and safety of an NMDA enhancer (NMDAE) as a monotherapy for the
treatment of schizophrenia.