Unilateral and bilateral ECT: a study of memory disturbance and relief from depression.

Fifty-one endogenous and reactive female depressives were given a course of either unilateral non-dominant, unilateral dominant, or bilateral ECT. Visual and verbal memory tests and confusion ratings were administered at frequent intervals during the treatment course. Pre-and post-treatment assessments of depression were made. Comparisons of the therapeutic effect of six and of eight ECTs were studied separately. One month after the last ECT the patients were again assessed on the memory and the depression tests. The results of the memory tests indicate that unilateral non-dominant ECT produced least memory disturbance (particularly of a verbal kind) and also less immediate confusion within 40 minutes of each ECT. This observation applies more to the reactive than the endogenous group. Comparisons of the depression tests reveal that unilateral non-dominant ECT is as effective in relieving depression as bilateral ECT, though progress may be less rapid. The observation holds true only for the reactive depressives. Endogenous depressives benefit more from bilateral ECT. Caution is advised against the administration of unilateral dominant ECT, since this group does not respond to treatment as well as the other two groups. Degree of improvement as a whole does not appear to be related to the degree of confusion experienced. The implications of these findings are discussed.