In two large European cohorts of well-defined patients with NT1 (n = 542), we found 1) low frequency of comorbid schizophrenia-like psychosis (<2%), and mostly in adult patients with NT1 onset in infancy and adolescence, and 2) no associations with antibodies to NR1/NR2B heteromers of the NMDAR. The gene discussed is GRIN2B; the disease is psychotic disorder.