Relative impact of diagnosis and clinical stage on response to electroconvulsive therapy: a retrospective cohort

Objectives: Electroconvulsive therapy (ECT) is commonly indicated for refractory psychiatric disorders. However, little research has compared response across diagnoses. Here, we aimed to evaluate the relative impact of diagnosis and clinical staging as response predictors in a cross-diagnostic sample. Methods: In a retrospective cohort of adult inpatients (n=287) who underwent at least six sessions of ECT, we investigated predictors of complete response (a clinical global impression of 1) to ECT. We use adjusted regression models to estimate the impact of clinical diagnosis and staging on complete response and dominance analysis to assess the relative importance of these predictors. Results: Those for whom a depressive episode was a primary indication for treatment were the most likely to have complete improvement, while those with psychosis were the least likely; clinical stage had a significant influence on outcome in all diagnoses. A diagnosis of psychosis was the strongest predictor of non-response. Conclusions: A diagnosis of psychosis (mainly schizophrenia) was the strongest predictor of non-response. We also found that clinical staging can aggregate information on ECT response that is independent of clinical diagnosis.