REVIEW OF: Melzer-Ribeiro DL et al, Schizophr Res 2024;268:252–260

STUDY TYPE: RCT

Electroconvulsive therapy (ECT) was originally developed for psychosis and is still used for treatment-resistant schizophrenia. A 2015 study reported a response rate of 50% in clozapine-resistant patients randomized to ECT versus treatment as usual (TAU) (Petrides G et al, Am J Psychiatry 2015;172(1):52–58). 

Melzer-Ribiero and colleagues sought to evaluate ECT in clozapine-resistant schizophrenia by using sham ECT as a control, rather than TAU. Sham ECT involves sedation, muscular paralysis, and the application of electrodes without an electrical stimulus. Forty outpatients were enrolled, with 21 and 19 randomized to the active and sham groups respectively. All patients had failed 2 other antipsychotics, had not responded to clozapine with serum levels above 350 ng/mL for at least 3 months, and scored greater than 60 on the Positive and Negative Symptoms Scale (PANSS). Each group received 2 bilateral treatments per week over 10 weeks and then were assessed using the PANSS at the conclusion of the trial. 

No significant differences were seen between groups on either the total PANSS or subgroup scores. Modest declines of 20%–40% were reported for about one third of patients in both groups, suggesting placebo drove the change in both groups. However, the researchers noted that their study was underpowered to detect an effect size of 0.5 or smaller. 

CARLAT TAKE

Though small, this is the second negative trial of ECT in clozapine-resistant schizophrenia, dampening the hopes for this avenue of treatment.