Association of Continuation and Maintenance Electroconvulsive Therapy With Relapse and Hospitalization Outcomes: A Retrospective Study of 134 Patients.

introductionElectroconvulsive therapy is an effective treatment for severe mood and psychotic disorders. However, remission after an acute course does not always prevent subsequent relapse. Continuation and maintenance electroconvulsive therapy may be used after the index course to reduce relapse risk and psychiatric hospitalization. The primary objective of this study was to examine the association between continuation or maintenance electroconvulsive therapy and relapse outcomes after an acute electroconvulsive therapy course. Secondary exploratory objectives were to assess hospitalization outcomes, diagnostic subgroup differences, and electroconvulsive therapy-related clinical characteristics.

methodsWe conducted a retrospective observational study including 134 patients who received electroconvulsive therapy in the psychiatric unit of the Grand Hôpital de l'Est Francilien, France, between January 2015 and January 2025. Sociodemographic and clinical characteristics, diagnosis, indication for electroconvulsive therapy, acute treatment parameters, use and duration of continuation or maintenance electroconvulsive therapy, Brief Psychiatric Rating Scale scores, adverse effects, relapse, rehospitalization, and length of hospital stay were collected from medical records. Patients receiving continuation or maintenance electroconvulsive therapy were compared according to treatment duration, with a distinction between protocols lasting six months or less and those continued beyond six months.

resultsAmong the 134 included patients, 53 patients received continuation or maintenance electroconvulsive therapy, and 81 did not. The mean age was 49.46 years, and 61.2% of patients were female. The most frequent diagnoses were unipolar depression, bipolar disorder, schizophrenia, and schizoaffective disorder. The acute course was associated with a substantial clinical improvement, with mean Brief Psychiatric Rating Scale scores decreasing from 69.6 before electroconvulsive therapy to 30.9 after treatment. Among patients receiving continuation or maintenance electroconvulsive therapy, those treated for more than six months had significantly fewer late relapses than those treated for six months or less. Electroconvulsive therapy was also associated with a significant reduction in hospital length of stay among patients with early relapse. Patients with psychotic disorders had higher relapse rates than those with mood disorders, particularly beyond six months.

conclusionsIn this retrospective cohort, the strongest signal was observed within the continuation/maintenance electroconvulsive therapy subgroup, where treatment beyond six months was associated with fewer late relapses than treatment lasting six months or less. Because of the retrospective non-randomized design, these findings should be interpreted as associative and hypothesis-generating rather than causal and support the integration of individualized maintenance electroconvulsive therapy strategies after an acute course while highlighting the need for prospective studies to define optimal duration and frequency.