Electroconvulsive therapy (ECT) is an effective option for treatment-resistant bipolar disorder (trBD). However, the mechanisms of its effect are obscure. Oxidative stress (OxS) is thought to be involved in the underpinnings of BD. Our study first to report the association between notable OxS parameters (superoxide dismutase, SOD; glutathione peroxidase; GSH-Px, catalase; CAT, and malondialdehyde, MDA) levels and ECT response in trBD patients.
Total 28 trBD patients and 49 controls were recruited. Six-week ECT and naturalistic follow-up were conducted. SOD, GSH-Px, CAT, and MDA levels were measured byenzyme-linked immunosorbent assay (ELISA), and the 17-item Hamilton Depression Rating Scale (HAMD-17) and Young Mania Rating Scale (YMRS) were administered at the baseline and the end of 6th week. Multiple analysis of covariance (MANCOVA), analysis of covariance (ANCOVA), 2×2 ANCOVA and a multiple regression model were conducted.
SOD levels were lower in both trBD mania and depression (p=0.001; p<0.001), while GSH-Px (p=0.01; p<0.001) and MDA (p<0.001; p=0.001) were higher in both trBD mania and depression compared to controls. CAT levels were positively associated with HAMD-17 scores in trBD depression (radjusted =0.83, p=0.005). MDA levels in trBD decreased after 6 weeks of ECT (p<0.001). Interestingly, MDA levels decreased in responders (p=0.001), but not in non-responders (p>0.05).
Our study indicates that decreased SOD could be a trait rather than a state in trBD. OxS levels are associated with illness severity and ECT response. This suggests that the mechanism of oxidative stress plays a crucial role in the pathophysiology of trBD.

© The Author(s) 2020. Published by Oxford University Press on behalf of CINP.