No. 30: Nov-Dec 1983
R.J. Berson has reviewed 33 cases of a curious delusion called Capgras' Syndrome. People displaying this syndrome believe that important people in their lives (family members, etc.) have been replaced by exact doubles. No hallucinations or illusions are involved; rather it is a belief. Those afflicted with Capgras' Syndrome may even believe that they themselves are represented somewhere by a double they never see. Not all persons with close emotional ties are believed to be doubled; and these un-replaced persons are always identified accurately. People with these beliefs usually possess normal perceptions and memories but are (obviously) disturbed emotionally with paranoid tendencies.
(Berson, Robert J.; "Capgras' Syndrome," American Journal of Psychiatry, 140:969, 1983.)
Comment. This strange mental state is apparently not related to autoscopy, where one hallucinates one's self.