This invention provides a method of enhancing NMDAR-mediated neurotransmission in a disease associated with NMDAR antibody production, said method comprising administering an NMDAR agonist, an alanine-serine-cysteine transporter inhibitor, a D-amino acid oxidase inhibitor, a glycine transport inhibitor or a combination thereof to said subject. This invention also provides a method of mitigating the severity of, mitigating the pathogenesis of, lowering the incidence of or treating a disease associated with NMDAR antibody production, said method comprising administering an agent, which is an NMDAR agonist, an alanine-serine-cysteine transporter inhibitor, a D-amino acid oxidase inhibitor, a glycine transport inhibitor or a combination thereof to said subject.