• We have set up guidelines for the practice of electroconvulsive therapy, based on Scandinavian clinical experience and research. Because the therapeutic effect is a result of the cerebral seizure, and the organic side effects partly consequences of the electrical stimulation, the aim should be to induce maximal seizure activity using minimal electrical energy. Essential features of optimal therapy are (1) absence of therapy with benzodiazepines and other anticonvulsant drugs, (2) superficial narcosis, (3) abundant oxygen supply, (4) threshold stimulation with brief-pulse stimuli, and (5) unilateral, parietotemporal, nondominant application of the electrodes. Seizure duration should always be measured to make sure that maximum seizure activity has taken place.