Cerebrospinal fluid neuromarker levels in patients with schizophrenia: a multiplex immunoassay study with a large sample

Aim To test the hypothesis that neuromarker alternations associated with diagnosis, symptoms, or psychotropic medication use can be found in schizophrenia, we measured cerebrospinal fluid (CSF) neuromarkers in patients with schizophrenia and healthy controls. Methods This cross‐sectional study comprised 148 patients with schizophrenia (39.0 ± 11.0 years; 88 men and 60 women) and 220 healthy controls (44.6 ± 14.8 years; 135 men and 85 women), all of Japanese ethnicity. The Positive and Negative Syndrome Scale (PANSS) was used to assess symptom severity in patients with schizophrenia. The levels of eight of the 18 CSF neuromarker were successfully measured using a multiplex immunoassay. Trait and state markers were identified by patient and control groups comparison and symptom‐correlation analyses, respectively. Results CSF glial fibrillary acidic protein levels were significantly higher in patients with schizophrenia than in healthy controls. CSF neurogranin, total tau, and YKL‐40 levels were significantly lower in patients with schizophrenia than in healthy controls. Particularly, in patients with schizophrenia, CSF neurogranin, total tau, and YKL‐40 levels were lower in the psychotropic‐medicated group than in the psychotropic‐medication‐free group. CSF amyloid beta 1–42 levels were significantly and negatively correlated with PANSS negative scores. CSF macrophage migration inhibitory factor levels were significantly and positively correlated with PANSS positive, general psychopathology, and total scores. CSF neural cell adhesion molecule‐1 and S100 calcium‐binding protein B levels were significantly and positively correlated with PANSS positive scores. Conclusion Our findings suggest trait and state neuromarkers and antidementia‐like effects of psychotropics on the pathology of schizophrenia.