Response rate and subjective memory after electroconvulsive therapy in depressive disorders with psychiatric comorbidity

Background: Response rates after and tolerability of electroconvulsive therapy (ECT) in depressive disorders with psychiatric comorbidity are uncertain. Methods: Data on patients with a depressive episode and a first course of ECT were collected from the Swedish National Quality Register for ECT. Logistic regression analyses, adjusted for gender, age, and depressive episode severity, were used to compare patients with and without comorbidity. The clinical response assessment Clinical Global Impression - Improvement Scale was used in 4413 patients and the memory item from the Comprehensive Psychiatric Rating Scale was used for subjective memory impairment rating after ECT in 3497 patients. Results: In patients with depressive disorder and comorbid personality disorder or anxiety disorder, 62.7% and 73.5%, respectively, responded after ECT compared with 84.9% in patients without comorbidity [adjusted odds ratio (aOR) 0.43, 95% confidence interval (CI) 0.34-0.55, and aOR 0.61, 95% CI 0.51-0.73, respectively]. The proportion of responding patients with comorbid alcohol use disorder was 77.1%, which was not significantly different from that in patients without comorbidity (aOR 0.75, 95% CI 0.57-1.01). The impact of comorbidity decreased with higher age and depressive episode severity. Subjective ratings of memory impairment did not differ between patients with and without comorbidity. Limitations: Observational non-validated clinical data. Conclusions: The response rate after ECT in depression may be lower with concurrent personality disorder and anxiety disorder; however, the majority still respond to ECT. This implies that psychiatric comorbidity should not exclude patients from ECT.