We have presented briefly a preliminary report on the results of a follow-up study of psychiatric patients treated by means of electrically induced convulsions and by means of metrazol convulsions. Of the former, 144 cases were studied and of the latter, 126 patients were studied, all cases being followed for periods exceeding six months subsequent to treatment. By evaluating the two fairly comparable groups treated by these two different means, it appears that the therapeutic effects of both methods are essentially the same, particularly in the psychotic patients. However, the statistics suggest that possibly the electric shock method may be slightly more efficacious, at least in so far as the immediate results are concerned. Therefore, and in consideration of certain undesirable effects and reactions of metrazol therapy, particularly in the psychoneurotic patients, it would seem warranted at the present time to discontinue metrazol treatments in favor of electric shock convulsive therapy, providing convulsive therapy is to be given.The convulsive treatments are undoubtedly of great value in the affective psychoses, seemingly producing a slightly more favorable response in the manic-depressive group than in the involutional psychosis group. It appeared that, regardless of the diagnostic category, if the clinical picture is characterized by depressive features, consciously expressed guilt feelings, feelings of worthlessness and self depreciation, and especially suicidal tendencies, convulsive shock therapy is of value and in fact seems to be highly specific for this type of symptomatology, often resulting in dramatic and prolonged remission of symptoms.Patients with prominent aggressive, belligerent and homicidal tendencies were not favorable subjects for convulsive therapy.Follow-up studies, including the complications or sequelae with respect to memory loss, incidence of vertebral fractures, neurological complications, electroencephalographic disturbances, and other changes will be included in a separate report.