From immune response to mental health: neutrophils in schizophrenia

Schizophrenia is a multifaceted psychiatric disorder with a complex etiology that includes genetic, environmental, and immunological factors. Emerging research has increasingly focused on the role of the immune system, particularly neutrophils, in the pathogenesis of schizophrenia. Neutrophils, the most abundant type of white blood cells, are crucial in the body's defense mechanisms against infections and in the regulation of inflammation. This review explores the evolving evidence that implicates neutrophils in schizophrenia, highlighting their potential contribution to the disorder's onset and progression through mechanisms such as neuroinflammation and oxidative stress. Recent studies have demonstrated elevated neutrophil counts and neutrophil-to-lymphocyte ratios (NLR) in individuals with schizophrenia, correlating with the severity of psychotic symptoms and cognitive impairments. Furthermore, genetic and molecular analyses have revealed abnormalities in neutrophil function and immune-related gene expression in schizophrenia patients. These findings suggest that neutrophil dysfunction and the resulting chronic inflammation could play a significant role in the disorder's pathophysiology, affecting neuronal function, and contributing to the clinical manifestations of schizophrenia. Neutrophil-related biomarkers, such as NLR, could aid in the diagnosis and monitoring of disease progression. Additionally, targeting neutrophil activity and associated inflammatory pathways presents a promising avenue for developing new therapeutic interventions. This review underscores the need for further research to elucidate the precise mechanisms by which neutrophils influence schizophrenia and to explore potential treatments that could improve outcomes for patients.