Our present state of knowledge concerning the changes brought about by shock therapy is such that the application of these forms of treatment is still largely empirical. This is due to the fact that we are not aware of the mode of action of these different modes of treatment and also because the classification of the various forms of mental disorders is still very unsatisfactory. This is particularly true when we are dealing with that heterogeneous group of mental illnesses lumped together as schizophrenia. Many cases of so-called schizophrenia will recover without and even in spite of shock therapy, and I very much doubt whether the concept schizophrenia has done anything to help us in choosing our cases. A diagnosis to have any value should give us (a) a clinical picture of the patient, (b) an indication of the course of the illness which would be helpful in giving a prognosis, and (c) some guidance as to the appropriate treatment for a particular patient. Most clinical psychiatrists will agree that the diagnostic label schizophrenia fails us in all these respects. I read with great interest in the booklet of the International Congress Dr. Meduna's article in which he divides schizophrenia into two groups (a) endogenous schizophrenia, and (b) symptomatic schizophrenia. He points out that shock therapy is of value only in cases of symptomatic schizophrenia, which is more or less identical with the confusional insanity and the exhaustion psychoses of the English Board of Control classification of mental diseases.