Clinical Effectiveness and Cognitive Impact of Electroconvulsive Therapy for Schizophrenia: A Large Retrospective Study

Objective: To determine the clinical effectiveness and cognitive impact of electroconvulsive therapy (ECT) in a large clinical sample of patients with schizophrenia and explore factors associated with treatment response and transient cognitive impairment.

Methods: We examined the clinical records of 144 patients with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder who were treated at an academic mental health hospital from October 2009 to August 2014. These patients received 171 acute courses of ECT; we attempted to determine their treatment response and transient cognitive impairment from ECT. We explored the impact of various factors including ECT indication, clinical characteristics, medication during ECT, and technical parameters on treatment response and transient cognitive impairment.

Results: Treatment with ECT resulted in a 76.7% response rate. Factors associated with a better response to ECT were absence of treatment with antiepileptic medication (17.9% vs 3.9%, P = .007), a previous good response to ECT (36.4% vs 15.4%, P = .017), and primary indication for ECT referral other than failed pharmacotherapy (89.7% vs 69.8%, P = .012). Factors not associated with treatment response included age, clozapine treatment, and benzodiazepine treatment (P > .05). Treatment with ECT caused transient cognitive impairment in 9% of treatment courses; no demographic or clinical factors were associated with cognitive impairment.

Conclusions: This work demonstrates the effectiveness of ECT for schizophrenia treatment and several factors associated with treatment response. The rate of transient cognitive impairment is lower than expected based on the rate of cognitive impairment seen in ECT for depression. ECT appears to be an effective treatment option for schizophrenia that is tolerated by the majority of patients.