ECT: the search for the perfect stimulus

Animal studies indicate that seizures can be produced reliably with a fraction of the electrical energy now required by currently available electroconvulsive therapy (ECT) instruments. This may result in further reduction of the side effects of ECT. The stimulus energy does not necessarily correspond to the energy deposited in the brain tissue, and electrostimulatory dosimetry needs further refinement. With these reservations, data are presented suggesting that the optimal stimulus, i.e., the stimulus capable of producing seizures reliably with the least energy, consists of brief, unidirectional pulses, between 40 and 60 microseconds in duration, applied at a frequency between 100 and 300 Hz. The relevance of these findings to the use of existing ECT instruments is discussed. A device capable of producing such a stimulus has been built and is awaiting clinical trials.