A brief review has been made of the different effects of different sites of electrode placement on mood and memory in the course of the electroconvulsive treatment of depressed patients. It appears that these treatments do not differ significantly in their power to alleviate depressive symptoms.
Most of the studies confirm that unilateral shock to the dominant side of the head (usually defined as the left side in right-handed patients) produces a transient defect of memory which may, in fact, be relatively specific to verbal material. Non-dominant shock, on the other hand, results in lesser defect and what temporary impairment it does produce may affect only memory for nonverbal material. The effect of bilateral stimulation may depend on how near the frontal position the electrodes are placed; the more anterior their placement the less may be the consequent impairment. These results seem analagous, though relatively mild and transient, to the more severe and lasting effects of temporal lobe surgery in man.
These latter observations suggest the need for the controlled study of yet another technique in which both electrodes would be placed in as frontal a position as possible consistent with the production of convulsion. It is predicted that such frontal stimulation should alleviate mood disorder but, at the same time, produce the least memory loss of all.
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