Electroconvulsive therapy for schizophrenia

• Published in: Cochrane database of systematic reviews 2002 (2), p.CD000076-CD000076
• Main Authors: Tharyan, P, Adams, C E
• Format: Article
• Language: English
• Subjects: Electroconvulsive Therapy; Humans; Randomized Controlled Trials as Topic; Schizophrenia - therapy
• ISSN: 1469-493X

Electroconvulsive therapy (ECT) involves the induction of a seizure (fit) for therapeutic purposes by the administration of a variable frequency electrical stimulus shock via electrodes applied to the scalp. The effects of its use in people with schizophrenia are unclear. To determine whether electroconvulsive therapy (ECT) results in clinically meaningful benefit with regard to global improvement, hospitalisation, changes in mental state, behaviour and functioning for people with schizophrenia, and whether variations in the practical administration of ECT influences outcome. Electronic searches of Biological Abstracts (1982-1996), EMBASE (1980-1996), MEDLINE (1966-2001), PsycLIT (1974-1996),SCISEARCH (1996) and the Cochrane Schizophrenia Group's Register (July 2001) were undertaken. The references of all identified studies were also inspected and authors contacted. All randomised controlled clinical trials that compared ECT with placebo, 'sham ECT', non-pharmacological interventions and antipsychotics, and different schedules and methods of administration of ECT for people with schizophrenia, schizoaffective disorder or chronic mental disorder. Studies were reliably selected, quality rated and data extracted. For dichotomous data, relative risks (RR) were estimated, with the 95% confidence intervals (CI). Where possible, the number needed to treat statistic (NNT) was calculated. Analysis was by intention-to-treat. Normal continuous data was summated using the weighted mean difference (WMD). Scale data was presented for only those tools that had attained pre-specified levels of quality. Tests of heterogeneity and for publication bias were undertaken. This review includes 24 trials with 46 reports. When ECT is compared with placebo or sham ECT, fewer people remain unimproved in the real ECT group (n=400, RR fixed 'not globally improved in the short term' 0.77 CI 0.6 to 0.9, chi-square 13.46 df=8 p=0.1). Removal of the one study with clearly heterogeneous results causes a change in the findings (n=380, 8 RCTs, RR fixed 0.83 CI 0.7 to 1.01), as does removal of a clinically heterogeneous trial (n=370, 8 RCTs, RR fixed 0.74 CI 0.6 to 0.9, chi-square 10.97 df=7 p=0.14). There was a suggestion that ECT resulted in less relapses than sham ECT (n=47, 2 RCTs, RR fixed 0.26 CI 0.03 to 2.2), and a greater likelihood of being discharged from hospital (n=98, 1 RCT, RR fixed 0.59, CI 0.34 to 1.01). There is no evidence that this early advantage for ECT is maintained over