We report a case of late-onset schizophrenia that required differentiation from a dementing disorder. The patient was an 83-year-old woman who had experienced auditory hallucinations since she was 67 years old. The patient had slightly elevated total tau and slightly decreased amyloid β1-42, cerebrospinal fluid biomarkers. This case was identified as late-onset schizophrenia. However, the results of cerebrospinal fluid biomarkers indicated that neurofibrillary tangles and neuronal death, which are characteristic of Alzheimer 's disease, may also have been present. Late-onset schizophrenia should be treated based on an appropriate differential diagnosis, including neuropathological consideration of dementing disorders.
Keywords: Cerebrospinal fluid biomarker; dementing disorder; late-onset schizophrenia; neuropathology; risperidone.