Schizophrenia (SZ) is a mental disorder characterized by neurocognitive dysfunctions and a reduction in occupational and social functioning. Several studies have provided evidence for mitochondrial dysfunction in the pathophysiology of SZ. In this sense, it is known that the addition of genetic variations in mitochondrial DNA (mtDNA) impairs oxidative phosphorylation of enzymatic complexes in mitochondria, resulting in ATP depletion and subsequent enhancement of reactive oxygen species; this is associated with cellular degeneration and apoptosis observed in some neuropsychiatric disorders. As a consequence of mitochondrial dysfunction, an increase in circulating cell-free mtDNA fragments can occur, which has been observed in individuals with SZ. Moreover, due to the bacterial origin of mitochondria, these cell-free mtDNA fragments in blood plasma may induce inflammatory and immunogenic responses, especially when their release is enhanced in specific disease conditions. However, the exact mechanism by which mtDNA could be released into blood plasma is not yet clear. Therefore, the aims of this review article were to discuss the participation of mtDNA genetic variations in physiopathologic mechanisms of SZ, and to determine the status of the disease and the possible ensuing changes over time by using circulating cell-free mtDNA fragments as a biomarker.

精神分裂症（SZ）是一种精神障碍，其特征在于神经认知功能障碍以及职业和社交功能的下降。几项研究为SZ的病理生理提供了线粒体功能障碍的证据。从这个意义上讲，已知线粒体DNA（mtDNA）中遗传变异的加入会损害线粒体中酶促复合物的氧化磷酸化，从而导致ATP耗竭并随后增强活性氧。这与某些神经精神疾病中观察到的细胞变性和凋亡有关。线粒体功能障碍的结果是，循环性无细胞mtDNA片段可能增加，这在患有SZ的个体中已观察到。而且，由于线粒体是细菌起源的，血浆中这些无细胞的mtDNA片段可能诱导炎症和免疫原性应答，尤其是在特定疾病条件下增强它们的释放时。但是，尚不清楚mtDNA释放到血浆中的确切机制。因此，本文的目的是探讨mtDNA遗传变异参与SZ的生理病理机制，并通过使用循环的无细胞mtDNA片段作为生物标记物来确定疾病的状况以及随时间推移可能发生的变化。