Oxidative Stress and Emergence of Psychosis

Abstract

Treatment and prevention strategies for schizophrenia require knowledge about the mechanisms involved in the psychotic transition. Increasing evidence suggests a redox imbalance in schizophrenia patients. This narrative review presents an overview of the scientific literature regarding blood oxidative stress markers’ evolution in the early stages of psychosis and chronic patients. Studies investigating peripheral levels of oxidative stress in schizophrenia patients, first episode of psychosis or UHR individuals were considered. A total of 76 peer-reviewed articles published from 1991 to 2022 on PubMed and EMBASE were included. Schizophrenia patients present with increased levels of oxidative damage to lipids in the blood, and decreased levels of non-enzymatic antioxidants. Genetic studies provide evidence for altered antioxidant functions in patients. Antioxidant blood levels are decreased before psychosis onset and blood levels of oxidative stress correlate with symptoms severity in patients. Finally, adjunct treatment of antipsychotics with the antioxidant N-acetyl cysteine appears to be effective in schizophrenia patients. Further studies are required to assess its efficacy as a prevention strategy. Redox imbalance might contribute to the pathophysiology of emerging psychosis and could serve as a therapeutic target for preventive or adjunctive therapies, as well as biomarkers of disease progression.

Evidence of Increased Oxidative Stress in the Placental Tissue of Women Who Suffered an Episode of Psychosis during Pregnancy

“…Pregnancy is strongly linked to OS, especially under pathological conditions [39]. Recent works have shown that patients with a first episode of psychosis show a reduced antioxidant status along with a marked increase in oxidative markers [22,40]. The environment in which the mother lives exposes the placental tissue to a set of chemical, physical and biological agents of OS, which may have pathological consequences in this organ [41].…”

“…Exclusion criteria were: meeting the diagnostic criteria for another Axis-I mental disorder or intellectual disability; or a history of neurodevelopmental disorders or head injury with loss of consciousness. The median age in the FE-PW group was 33.5 years, and the median gestational age was 40 (38)(39)(40)(41) weeks. For HC-PW, the median age was 33.5 (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39) years, and the median gestational age was 40 (39)(40)(41)(42) weeks.…”

“…The median age in the FE-PW group was 33.5 years, and the median gestational age was 40 (38)(39)(40)(41) weeks. For HC-PW, the median age was 33.5 (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39) years, and the median gestational age was 40 (39)(40)(41)(42) weeks. The sociodemographic and clinical features of these patients are summarized in Table 1.…”

Major Depressive Disorder and Oxidative Stress: A Review of Peripheral and Genetic Biomarkers According to Clinical Characteristics and Disease Stages

“…For metabolomic parameters, inclusion and exclusion criteria were adapted from Rambaud et al [ 23 ] for use with MDD. The keywords used for the search were: (“depression” OR “major depression” OR “major depressive disorder” OR “major depressive episode”) AND (“antioxidant” OR “oxidative stress”).…”

“…Interestingly, the brain is more vulnerable to oxidative stress due to its high metabolic rate and lower antioxidant levels [ 18 , 21 ]. Therefore, growing evidence shows the involvement of oxidative stress in brain-related diseases, such as Alzheimer’s disease, schizophrenia, and MDD [ 19 , 20 , 23 ].…”