Oxidative stress biomarkers and cognition in individuals with schizophrenia: study protocol for a systematic review and meta-analysis

Schizophrenia is a severe mental illness associated with substantial cognitive impairment and increased premature mortality. Although the etiology of cognitive dysfunction in schizophrenia is multifactorial, growing evidence suggests that oxidative stress may play a key role in its pathophysiology. Oxidative stress, resulting from an imbalance between reactive oxygen species production and antioxidant defenses, can cause neuronal damage, particularly in the brain, which is highly vulnerable due to its metabolic demands. Previous studies have reported alterations in oxidative stress biomarkers in individuals with schizophrenia; however, findings remain inconsistent, and their relationship with cognitive performance has not yet been comprehensively synthesized. This study aims to systematically review and meta-analyze the available evidence on the association between oxidative stress biomarkers and cognitive functions in adults with schizophrenia.