[Efficacy of electroconvulsive therapy: a systematic review of scientific evidences].

We carried out a systematic study of bibliographical review of scientific evidence provided by clinical trials that assessed the short, medium and long-term efficacy of electroconvulsive therapy (ECT) from 1965 until June 2003. The studies with the following features have been excluded: a) those in which ECT is not the aim of the research; b) those that do not compare ECT with another different treatment; c) those in which the aim of the research is not to evaluate the efficacy of ECT, and d) those in which the studies are not randomized clinical trials. We have used the biomedical databases Medline, Psyclit, IME and Cochrane. On applying the corresponding search strategies on every bibliographical repertory, a total amount of 916 studies were found, which were reduced to 62 after having applied the specified exclusion criteria. The scientific evidence obtained, which compare the efficacy of ECT exclusively in depression, schizophrenia, mania and Parkinson disease, are systematized.