Circulating Cell-Free Mitochondrial DNA in Plasma of Individuals with Schizophrenia and Cognitive Deficit in Mexican Population

Cognitive domains are affected in patients with schizophrenia. Mitochondrial dysfunction has been proposed as a possible origin of these symptoms. Cell-free mitochondrial DNA (cf-mtDNA) is an indicator of cellular stress, and it can be identified in individuals with age-associated disorders, this study aimed to explore the presence of cf-mtDNA in plasma of schizophrenia patients and its association with cognitive deficit. Ninety-nine subjects were clinically evaluated; the case group included 60 patients diagnosed with schizophrenia and 39 randomly-individuals without psychiatric disorders were included in the comparison group. Cognitive status (MoCA scale) and cell-free mtDNA in blood plasma were assessed and quantified in both groups. From the original sample, cf-mtDNA was identified in 43 subjects, 40 patients with schizophrenia and 3 controls (Χ = 31.10, p-value < 0.0001). Thirty-nine out of forty patients with schizophrenia had a cognitive deficit. According to our findings, cognitive impairment and presence of cf-mtDNA were related in subjects with schizophrenia. Thus, while the cognitive deficit might reflect an accelerated aging process, the cf-mtDNA plays a role as a potential biomarker in this mechanism.