The Relationship Between Depression Symptoms and Anxiety Symptoms During Acute ECT for Patients With Major Depressive Disorder

Background: We investigated the efficacy of electroconvulsive therapy in patients with major depressive disorder and concomitant anxiety symptoms and explored the relationships between depression symptoms and anxiety symptoms during acute electroconvulsive therapy. Methods: Major depressive disorder inpatients (N = 130) requiring electroconvulsive therapy were recruited for a maximum of 12 treatments each. Depression symptoms, using the core factor subscale derived from the 17-item Hamilton Depression Rating Scale, and anxiety symptoms, using the anxiety/somatization subscale from the Hamilton Depression Rating Scale-17, were assessed before electroconvulsive therapy, after every 3 electroconvulsive therapy treatments, and after the final electroconvulsive therapy. Both core factor subscale and anxiety/somatization subscale scores were converted to T-score units to compare the degrees of changes between depression symptoms and anxiety symptoms after electroconvulsive therapy. The relationships between core factor subscale and anxiety/somatization subscale were analyzed using the crosslagged longitudinal model during acute electroconvulsive therapy. Results: A total 116 patients who completed at least the first 3 electroconvulsive therapy treatments were included in the analysis. Reduction of core factor scale T-scores was significantly greater than that of anxiety/somatization subscale T-scores. The model satisfied all indices of goodness-of-fit (chi-square = 30.204, df = 24, P = 0.178, Tucker-Lewis Index = 0.976, Comparative Fit Index = 0.989, Root Mean Square Error of Approximation = 0.047). Core factor subscale changes did not definitely predict subsequent anxiety/somatization subscale changes. Conclusions: Electroconvulsive therapy is effective in the acute treatment of major depressive disorder patients associated with anxiety symptoms. Anxiety symptoms improved less than depression symptoms during acute electroconvulsive therapy. However, earlier reduction in depression symptoms does not definitely drive subsequent relief in anxiety symptoms.