1. Recurring manic-depressive illnesses can frequently be prevented by the technique of prophylactic electroshock.2. Persons whose manic-depressive illnesses are very prolonged or frequently recurrent, and who do not respond adequately to electroshock, may respond to prefrontal lobotomy.3. Persons whose attacks are very infrequent may have such attacks aborted by the intensive application of electroshock at the first appearance of prodromal symptoms.4. Failures of prophylactic electroshock are more likely to occur when the patient is faced with insoluble frustrating environmental factors. Hence the need for adequate social psychotherapy.5. Because of the dislike many patients have for electroshock every effort should be put forth to make the prophylactic electroshock as free as possible from unpleasant features.6. Good aftercare is essential.7. Prophylactic electroshock is of limited value in recurring schizophrenic illnesses.