Systemic oxidatively generated DNA/RNA damage in clinical depression: Associations to symptom severity and response to electroconvulsive therapy

BackgroundDepression has been associated with increased oxidative stress and hypothesized to accelerate aging. Nucleic acid damage from oxidation is a critical part of the aging process, and a suggested early event in age-related somatic morbidities that are also prevalent in depression, such as dementia and type 2 diabetes. We hypothesized that increased severity of depression is associated with increased systemic oxidatively generated DNA and RNA damage, and that this increase is attenuated by an effective antidepressant treatment.MethodsThe urinary excretion of markers of systemic oxidatively generated DNA and RNA damage, 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), respectively, were determined in healthy controls (N=28), moderately depressed, non-medicated patients (N=26) and severely depressed patients eligible for electroconvulsive therapy (ECT) (N=29). In the severely depressed patient group, samples were also obtained 1 week after the completion of ECT.ResultsSystemic RNA damage from oxidation, as measured by 8-oxoGuo excretion, was higher with increasing severity of depression (controls