The Nottingham electroconvulsive therapy (ECT) trial was designed with a simulated treatment group to test prospectively the power of delusions or agitation to predict response. The response of patients without retardation and without delusions was examined retrospectively as well because of doubts over the usefulness of ECT for this subgroup. Deluded/nondeluded and agitated/nonagitated subtypes responded significantly to real treatment. Neither delusions nor agitation predicted greater treatment response. Patients without retardation, with or without delusions responded to real ECT, supporting the continuing prescription of ECT for these patients as well.