Lowered serum cesium levels in schizophrenia: Association with immune-inflammatory biomarkers and cognitive impairments

Objectives: A previous study has shown that schizophrenia (SCZ) is accompanied by lowered levels of trace/metal elements, including cesium. However, it is not clear whether changes in cesium, rubidium, and rhenium are associated with activated immune-inflammatory pathways, cognitive impairments, and the symptomatology of SCZ. Methods: This study measured cesium, rubidium, and rhenium, cognitive impairments (using the Brief Assessment of Cognition in Schizophrenia [BACS]), and the levels of cytokines/chemokines interleukin (IL)-ip, tumor necrosis factor (TNF)-a, and eotaxin (CCL11) in 120 patients with SCZ and 54 healthy controls. Severity of illness was assessed using the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), the Fibromyalgia and Chronic Fatigue Syndrome Rating (FF) Scale, and the Hamilton Depression Rating Scale (HAM-D). Results: Serum cesium was significantly lower in patients with SCZ as compared with controls. Further, serum cesium was significantly and inversely associated with CCL11 and TNF-a, but not IL-1 b, in patients with SCZ; significant inverse associations were also noted between serum cesium levels and BPRS, FF, HAM-D, and SANS scores. Finally, cesium was positively correlated with neurocognitive probe results including the Tower of London, Symbol Coding, Controlled Word Association, Category Instances, Digit Sequencing Task, and List Learning tests. Conclusion: The results suggest that lowered serum cesium levels may play a role in the pathophysiology of SCZ, contributing to specific symptom domains including negative, depressive and fatigue symptoms, neurocognitive impairments (spatial working, episodic, and semantic memory and executive functions), and neuroimmune pathways.