Background: In the past few decades, increasing evidence in the literature has appeared
describing the role of the antioxidant defense system and redox signaling in the multifactorial
pathophysiology of psychosis. It is of interest to clinicians and researchers alike that abnormalities
of the antioxidant defense system are associated with alterations of cellular membranes, immune
functions and neurotransmission, all of which have some clinical implications.
Methods: This narrative review summarizes the evidence regarding oxidative stress in the early
stages of psychosis. We included 136 peer-reviewed articles published from 2007 to 2020 on
PubMed EMBASE, The Cochrane Library and Google Scholar.
Results: Patients affected by psychotic disorders show a decreased level of non-enzymatic antioxidants,
an increased level of lipid peroxides, nitric oxides, and a homeostatic imbalance of purine
catabolism. In particular, a significantly reduced antioxidant defense has been described in the early
onset first episode of psychosis, including reduced levels of glutathione. Also, it has been shown
that a decreased basal low-antioxidant capacity correlates with cognitive deficits and negative
symptoms, mostly related to glutamate-receptor hypofunction. In addition, atypical antipsychotic
drugs seem to show significant antioxidant activity. These factors are critical in order to treat cases
of first-onset psychosis effectively.
Conclusion: This systematic review indicates the importance that must be given to anti-oxidant defense