Augmentation of clozapine with ECT: a retrospective case analysis

Abstract

Objective: We sought to assess the effectiveness of clozapine augmentation with Electroconvulsive therapy (ECT) (C+ECT) in patients with clozapine-resistant schizophrenia.

Methods: We conducted a retrospective review of electronic health records to identify patients treated with C+ECT. We determined the response to C+ECT and the rate of rehospitalisation over the year following treatment with C+ECT.

Results: Forty-two patients were treated with C+ECT over a 10-year period. The mean age of the patients at initiation of ECT was 46.3 (SD = 8.2) years (range 27-62 years). The mean number of ECTs given was 10.6 (SD = 5.3) (range 3-25) with the majority receiving twice weekly ECT. Seventy-six per cent of patients (n = 32) showed a Clinical Global Impression-Improvement (CGI-I) score of ≤3 (at least minimally improved) following C+ECT. The mean number of ECT treatments was 10.6 (SD = 5.3) (range 3-25) with the majority receiving twice weekly ECT. Sixty-four per cent of patients experienced no adverse events. Response to C+ECT was not associated with gender, age, duration of illness or duration of clozapine treatment. Seventy-five per cent of responders remained out of hospital over the course of 1-year follow-up, while 70% of those with no response to C+ECT were not admitted to hospital. Three patients received maintenance ECT, one of whom was rehospitalised.

Conclusion: This study lends support to emerging evidence for the effectiveness of C+ECT in clozapine-resistant schizophrenia. These results are consistent with the results of a meta-analysis and the only randomised controlled trial (RCT) of this intervention. Further RCTs are required before this treatment can be confidently recommended.

Keywords: clozapine; electroconvulsive therapy; psychosis; schizophrenia; treatment-resistant.