Predictors of Treatment Response to Electroconvulsive Therapy in Schizophrenia - A Nationwide Registry-Based Study

Abstract

Introduction: Up to 30% of patients with schizophrenia respond insufficiently to antipsychotic drugs. Electroconvulsive therapy (ECT) has been reported to effectively augment the effects of antipsychotics in some of these patients. To date, there are few established predictors of treatment response to ECT in patients with schizophrenia. Aims: The primary aim was to determine the response rate to ECT in patients with schizophrenia. The secondary aim was to investigate predictors of treatment response. Methods: All patients admitted to any Swedish hospital for schizophrenia from 2011 to 2017, who were treated with ECT while in inpatient care, were included in the Swedish National Quality Registry for ECT (Q-ECT), and were assessed using the Clinical Global Impression - Improvement (CGI-I) scale after treatment were included. CGI-I scores of 1 or 2 were considered a response to treatment. Multiple national registries were used to obtain information on demographics and clinical variables. Results: The study included 285 patients who were concurrently treated with antipsychotic drugs. The response rate to ECT was 73.0%. Among those patients with outcome data, treatment with long-acting injectable antipsychotics was predictive of a better response, whereas comorbid substance use disorders were predictive of a worse response. Conclusion: This study provides new evidence on predictors of who might respond among patients with schizophrenia treated by ECT. Additional studies of ECT in schizophrenia are needed.