Electroconvulsive Therapy Versus Aripiprazole Addition to Clozapine in Patients with Clozapine-Resistant Symptoms (EMECLO): A Protocol of a Single-Blind, Multicenter, Randomized-Controlled Feasibility Trial.

Background: Currently, guidance on the most effective treatment for patients with clozapine-resistant schizophrenia-spectrum disorders (SSD) is lacking. While augmentation strategies to clozapine with aripiprazole and electroconvulsive therapy (ECT) have been demonstrated to be effective in patients with clozapine-resistant schizophrenia spectrum disorders (CRS), head-to-head comparisons between these addition strategies are unavailable. We therefore aim to examine the feasibility of a larger randomized, single-blind trial comparing the effectiveness, cost-effectiveness, and safety of aripiprazole addition vs. ECT addition in CRS.

Methods: In this multi-center, randomized, single-blind feasibility study, the feasibility of recruiting 20 participants with CRS who will be randomized to either aripiprazole or bilateral ECT addition will be assessed. The main endpoint is the number of patients willing to be randomized. The number of screened individuals and reasons to decline participation will be recorded. Effects will be estimated for the benefit of the foreseen larger trial. To that end, differences between both arms in symptom severity will be assessed using blinded video assessments. In addition, tolerability (e. g., cognitive functioning), safety, quality of life, recovery, and all-cause discontinuation will be compared. The follow-up period is 16 weeks, after which non-responders will be given the option to switch to the other treatment.

Discussion: Strengths of this feasibility trial include maintaining blinding with video assessment, a possibility to switch groups in case of non-response, and a broad set of outcome measures. Identification of factors contributing to non-participation and drop-out will generate valuable information on trial feasibility and may enhance recruitment strategies in a follow-up RCT.

Trial registration: The study has been approved by the Medical Research Ethics Committee of the Amsterdam University Medical Center, location AMC, and was registered on 1 May 2022 in the EU Clinical Trials Register (EudraCT) under the trial name 'EMECLO' (2021-006333-19).