Abstract: A recombinant, synthetic or monoclonal human antibody or fragment thereof that binds to an N-methyl-D-aspartate Receptor (NMDAR) epitope, which antibody or fragment comprises at least one a heavy chain variable domain sequence encoded by a nucleic acid sequence that is at least 80% identical to SEQ ID NOs. 1, 3, or 5; or at least one a light chain variable domain sequence encoded by a nucleic acid sequence that is at least 80% identical to SEQ ID NOs: 2, 4, or 6. Assays for diagnosis of ANRE employ these NMDAR-binding antibodies, constructs, or epitope binding fragments. In one embodiment, multiple of the NMDAR-binding antibodies or fragments are used as controls because they bind non-overlapping target sequences on the NMDAR ATD.