While electroconvulsive therapy (ECT) is an effective treatment for depression, patient responses vary. In addition, there is a lack of guidance in treatment decisions for patients with an initial non-responsive trajectory. This study aimed to identify distinct latent patient trajectories and to explore outcomes among patients who had not responded after nine treatments but continued therapy. In this register-based cohort study, including 344 patients (61% female), we applied a latent class mixed model to identify latent patient trajectories, and investigated variables associated with class affiliation in a multinomial regression analysis. We also identified non-responders at treatment nine and investigated final outcomes in a logistic regression model. Three latent classes were identified, all showing improvement, albeit class two and three showed faster and steeper symptom reduction, with mean MADRS post-ECT of 9.8 and 5.3, respectively. Class one depicted a shallower response pattern, with mean MADRS post-ECT of 20.9, variables associated with affiliation to this class were longer duration of depressive episode, non-psychotic depression, lower age and lower baseline depression level. Of non-responders to ECT at session nine, 44.9% achieved final response and 17.9% remission, female sex and lower age were associated with higher odds of final non-response. Our study supports ECT as an effective treatment for depression, while highlighting the existence of distinct response trajectories. For patients with an initial non-response trajectory, a significant proportion may still benefit from continued ECT. Our findings reinforce the importance of individualized treatment decisions guided by clinical response and close monitoring.
Sellevåg et al. (Sun,) studied this question.