The influence of age on ECT efficacy in depression, mania, psychotic depression and schizophrenia: A transdiagnostic analysis

Aim: ECT use is variable across age groups. We aim to investigate the effect of age on ECT response among patients with depression, psychotic depression, mania and schizophrenia. Methods: Our retrospective observational study included patients from the Institute of Mental Health (Singapore) who were initiated on ECT (March 2017-February 2023). MADRS and BPRS scores were assessed 1-2 days before the first ECT and after the 6th session. The association between age group and ECT response was analyzed by ANOVA and generalized linear regression. A one-way sensitivity analysis was performed with age as a continuous variable. Results: 166 (15.7%) patients were "young-age (<= 26 years)", 634 (60%) patients were in the "middle-age (27-59 years)" group and 256 (24.3%) were "old-age (>= 60 years)". The association between older age and post-ECT improvement in patients with depression was significant in the categorical age analysis but it did not persist in the sensitivity analysis. No significant association between age and ECT response was noted in patients with bipolar disorder and schizophrenia as evidenced by both categorical and continuous age analyses. In a small subgroup with psychotic depression, younger patients improved significantly more than older patients post-ECT. Conclusion: Patients with unipolar or bipolar depression, mania, or schizophrenia, regardless of age, respond favourably to ECT. Other associated factors such as psychomotor and psychotic symptoms, disease severity and number of failed pharmacotherapies should be considered in predicting ECT response. Younger patients with psychotic depression may respond better to ECT.