background Failure to respond to antidepressants is probably the most common indication for electroconvulsive therapy (ect). Opinions seem to be divided as to whether medication resistance has a negative influence on the efficacy of subsequent ect.
aim To perform a systematic review to investigate the effect of previous pharmacotherapy failure on the efficacy of ect.
methods Relevant cohort studies were identified from systematic search of the PubMed electronic database.
results Seven studies were included in this meta-analysis: the overall remission rate amounts to 48.0% (281/585) for patients with and 64.9% (242/373) for patients without previous pharmacotherapy failure. An exact analysis with the Mantel-Haenszel method shows a reduced efficacy of ect in patients that received previous pharmacotherapy.
conclusion The efficacy of ect is significantly superior in patients without previous pharmacotherapy failure as compared with medication-resistant patients. Since this finding is based on observational studies, it might be caused by a confounding factor, e.g. the presence of psychotic features or the duration of the index episode. ect appears to be an effective treatment for severely depressed patients, as well as for patients with previous pharmacotherapy failure.