Changes in Glutathione and Homocysteine Concentrations in Treatment-Resistant Depression After Electroconvulsive Therapy.

BACKGROUND Electroconvulsive therapy (ECT) is one of the most effective treatment for drug-resistant depression, but the search for reliable biological predictors of its efficacy remains in-conclusive. Glutathione and homocysteine have been proposed as potential markers of oxidative stress involvement in mood disorders. MATERIAL AND METHODS We retrospectively analyzed clinical data and collected serum samples from 54 patients with treatment-resistant depression (46.3% with major depressive disorder, 53.7% with bipolar disorder) who had undergone a series of bilateral ECT. Serum concentrations of glutathione and homocysteine were measured before and after treatment. Patients were anesthetized with thiopental or thiopental combined with ketamine. Clinical improvement was assessed using the 17-item Hamilton Depression Rating Scale. RESULTS ECT significantly reduced Hamilton Depression Rating Scale scores (P<0.0001). No significant changes were observed in serum glutathione or homocysteine concentrations after treatment, and no correlations were found between biomarker levels and clinical response, remission, or anesthetic type. However, patients with bipolar disorder showed consistently higher glutathione levels than those with unipolar disorder (P<0.05). CONCLUSIONS Neither homocysteine nor glutathione levels were associated with ECT response, suggesting limited utility of these markers as predictors of clinical outcome. Elevated glutathione in patients with bipolar disorder may suggest potential biological differences between mood disorder subtypes; however, further prospective studies are required to confirm this observation. Further studies are needed to clarify the clinical significance of oxidative stress markers in ECT.