Influence of episode duration of major depressive disorder on response to electroconvulsive therapy

Longer duration of major depressive episode is supposed to decrease response to electroconvulsive therapy (ECT). Most studies on the subject are dated and their population differs from ours, therefore their results may not be applicable to our population of severely depressed inpatients.

We reviewed the records of 56 consecutive inpatients with major depressive disorder according to DSM-III-R criteria and assessed each patient's episode duration. We examined whether episode duration has an effect on response to ECT.

Episode duration has no significant effect on response to ECT, according to both a reduction on the Hamilton Rating Scale for Depression (HRSD) of at least 50% and a post-treatment HRSD score

The present study has a limited sample size and concerns a rather homogeneous population of severely depressed inpatients. Episode duration was established retrospectively.

ECT is an effective treatment for severely depressed inpatients, independent of episode duration.