Examining the clinical effectiveness of continuation and maintenance electroconvulsive therapy in schizophrenia

Objective: There are few studies that examine the effectiveness of Continuation/Maintenance Electroconvulsive Therapy (C/M-ECT) in schizophrenia, despite the documented effectiveness of acute ECT treatment. We aimed to investigate the clinical effectiveness of C/M-ECT for in-patients with Schizophrenia in a naturalistic setting. We examined the medical records of 46 in-patients who were diagnosed with Schizophrenia and had received C/M-ECT belonging to non-acute extended care service in a public psychiatry hospital in Sydney, Australia. The focus of analysis was on 138 treatment cycles (71 acute only cycles and 67 acute-continuation/maintenance cycles) across 45 subjects. A linear mixed effects model was used to describe the change in clinical global impression-severity (CGI-S) over time 4 time points viz., pre-post acute and pre-post continuation/maintenance ECT. Results: Acute-only cycles and acute-continuation/maintenance cycles had identical pre- (M = 5, C.I. = 4-6), post-cycle CGI-S scores, and identical CGI-S difference scores (M = 0, C.I. = -1 - 1). Broadly in each continuation/maintenance cycle, we observed an initial sharp decrease in CGI-S scores followed by a logarithmic increase in scores over time, with satisfactory CGI-S score maintenance observed for approximately 6 months. Bitemporal ECT influenced CGI-S across maintenance ECT (p < 0.05) indicating smaller declines in CGI-S scores over time. Conclusion: In schizophrenia, C/M ECT preserves effects on illness severity for at least upto 6 months following an acute course of ECT. Bitemporal ECT vis a vis other electrode positions differentiated clinical severity over time.