The efficiency of ECT: II. Correlation of specific treatment variables to response rate in unilateral ECT

Determining the most efficient use of electroconvulsive therapy (ECT) for treating depression hinges on defining the crucial variable(s) related to the maximal efficacy of an individual seizure. In this study, we examined the relationships of several treatment variables to antidepressant effect of 109 individual unilaterally induced seizures. The seizures occurred during the maximal response phase of 39 courses of ECT judged to have been effective. The patients were divided according to whether or not they were receiving antidepressants during ECT. The variables were treatment number, seizure length, and type of seizure end point. In the total group, earlier treatments were significantly related to antidepressant effect. Seizure length and type of seizure end point appeared to be of little consequence. Further studies of ECT should focus particularly on the effects of the first treatment in order to define optimal ECT efficiency.