The relationship of oxidative metabolism to treatment response in major depression: A biological basis for treatment duration

Abstract

Background: We aimed to determine the relationship between antidepressant treatment and oxidative metabolism in patients with major depression. Materials and methods: Two groups, the patients diagnosed with depression (N = 21), and healthy controls (N = 40), were enrolled in the study. The patients received naturalistic antidepressant treatment. Serum samples were collected prior to treatment and at the end of the 8 weeks of antidepressant treatment. Those participants in the control group were sampled only once. The total antioxidant status (TAS) and total oxidant status (TOS) were measured and oxidative stress index (OSI) was calculated. Severity of depression in patients was also measured both prior to and after 8 weeks of antidepressant treatment. Results: In terms of TAS, TOS, and OSI there were significant differences between the groups both at the baseline. Baseline and final HAM-D scores of the patient group differed significantly. The baseline TAS, TOS, and OSI levels of patients did not change significantly after antidepressant treatment. The duration of illness was not correlated with baseline serum levels of TAS, TOS, and OSI. Patients who were deemed to be unresponsive to the antidepressant treatment differed significantly from the controls both at the baseline and at the final visit for TAS, TOS, and OSI. Additionally, treatment responsive patients did not show any similar difference in terms of TOS and OSI levels. Discussion: Chronic increase in anti-oxidant and oxidant levels in patients with major depression may be related to the elevation of anti-oxidant defenses that were developed in response to increased oxidative metabolism. © 2011 Elsevier GmbH. All rights reserved.