Association of Pre-ECT Anxiety Symptoms With Electroconvulsive Therapy Treatment Efficacy in Schizophrenia: A Retrospective Observational Cohort Study.

OBJECTIVES: Pre-ECT anxiety symptoms are common among patients undergoing Electroconvulsive Therapy (ECT). In this retrospective observational cohort study, we aim to explore the association between pre-ECT anxiety symptoms and ECT treatment outcomes in patients with schizophrenia. METHODS: We conducted a retrospective analysis of 979 patients with schizophrenia or schizoaffective disorder who received ECT at a tertiary public psychiatric hospital in Singapore. Patients were categorized into two groups based on the mean value of pre-ECT Brief Psychiatric Rating Scale (BPRS) anxiety subdomain score: with anxiety (>6) and without anxiety (≤6). Changes in clinical outcomes were measured using BPRS-psychotic, BPRS-anxiety, BPRS-negative and BPRS-manic subscale, Global Assessment of Functioning, Clinical Global Impression-improvement (CGI-I), EuroQoL-5 Dimension Visual Analogue Scale (EQ-5D-VAS) and Montreal Cognitive Assessment (MoCA) scale. Associations between the pre-ECT anxiety scores and patient sociodemographic, psychiatric symptom subscales, and functional assessments were analyzed. RESULTS: Younger age, a history of ECT, and concurrent antidepressant use were significantly associated with pre-ECT anxiety symptoms. Higher pre-ECT anxiety scores were positively correlated with psychotic, negative, and manic symptom severity, and were negatively correlated with general functioning and subjective quality of life (EQ-5D-VAS) (P<0.001). Pre-ECT anxiety was significantly negatively associated with ECT treatment efficacy measured using CGI-I (adjusted β=-0.11, P=0.03; η²=0.01). CONCLUSION: Our preliminary findings highlight the importance of assessing anxiety symptoms before ECT. Future prospective studies using validated anxiety-specific instruments are needed to further examine and confirm the association between pre-ECT anxiety symptoms and ECT treatment outcomes.