A study of index for estimating effect of electroconvulsive therapy based on electroencephalogram

In this paper, we study indices based on electroencephalogram (EEG) for estimating effect of electroconvulsive therapy (ECT) on patients with depression. ECT is an effective treatment for psychiatric disorders such as depression, schizophrenia, and applied to patients who fail to respond to drug therapy. Since the parameters of ECT such as intensity, duration, and timing of electrical simulation are determined from the experience of medical doctors, they are not necessarily appropriate. In order to find the best parameters for each patient an objective index of the efficacy of ECT has to be established. For this purpose we examine correlation between the recovery of some clinical scales and the changes of feature quantities obtained from EEG. The result suggests that the change of the increasing speed of spectral entropy (SE) after cerebral seizure may be used as an index of the efficacy of ECT.