Although the electrical treatment of mental disorders is still in the empirical stage, its use is well established. Certain features and principles of treatment have been elucidated in the published reports, and all are agreed that it is specific for melancholic states.

The evaluation of the scope and usefulness of E.C.T. would be enhanced by the comparative study of case material from various clinics, but much in the published reports is not strictly comparable because of the unavoidable variation in the assessment of diagnosis and the degree of recovery. In our case material collected over a period of five years we have endeavoured to present the facts with a minimum of subjectivity by limiting our observation as far as possible to measurable data. In order to reduce the variable factor of diagnosis, some 700 psychotics treated with electrically induced convulsions have been reconsidered and 500 selected for analysis after carefully excluding the overlapping types, particularly those cases presenting features of both affective and schizophrenic psychoses. The selected cases can therefore be regarded as classical examples clearly separated into the two large groups of biogenetic psychoses—schizophrenic and manic-depressive, including involutional melancholia.