Association of Clinical and Demographic Characteristics With Response to Electroconvulsive Therapy in Mania

IMPORTANCE: Knowledge of the effectiveness of electroconvulsive therapy (ECT) in the treatment of manic episodes is based on clinical experience, but empirical evidence is scarce. Moreover, prognostic factors associated with response to ECT in patients with mania are poorly understood. OBJECTIVE: To investigate the response to ECT in patients with manic episodes. DESIGN, SETTING, AND PARTICIPANTS: This nationwide, register-based observational cohort study was conducted using data from patients admitted to psychiatric departments in Sweden that reported data to the Swedish National Quality Registry for ECT (Q-ECT). Patients admitted to any hospital in Sweden and receiving ECT for a manic episode between 2012 and 2019 were considered for inclusion (605 individuals). The outcome, Clinical Global Impression Improvement scale (CGI-I) score, was available in 571 patients. Data from several national registers were combined to determine clinical and sociodemographic factors. Analysis of data occurred from April through September 2021. EXPOSURES: Patients treated with ECT for a mania were identified from the Q-ECT. MAIN OUTCOMES AND MEASURES: Response to ECT was defined by a CGI-I score of 1 (very much improved) or 2 (much improved). Remission was defined as a Clinical Global Impression Severity scale (CGI-S) score of 1 (reference range or not ill) or 2 (minimally ill) within 1 week after ECT. Univariate and multivariable regression models were used to investigate associations of sociodemographic factors, psychopharmacology, and comorbidities with response. RESULTS: Among 571 patients with mania treated with ECT (211 [37.0%] men; median [IQR] age, 46 [31-59] years), 482 patients (84.4%) responded to ECT. Comorbid anxiety and obsessive-compulsive disorder (OCD) were associated with lower odds of response to ECT (adjusted odds ratio [aOR], 0.48; 95% CI, 0.25-0.90 and aOR, 0.17; 95% CI, 0.06-0.56, respectively). Patients who were markedly ill (aOR, 2.93; 95% CI, 1.23-7.00), severely ill (aOR, 2.60; 95% CI, 1.06-6.34), or among the most extremely ill (aOR, 7.94; 95% CI, 2.16-29.21) according to CGI-S score had higher odds of response than those with mild or moderate illness. CONCLUSIONS AND RELEVANCE: This study found that ECT was associated with improvement for mania in clinical settings, with especially high response rates in patients with severe illness and those without comorbid anxiety or OCD.