Waking up in hospital after a neurological event can be a disturbing experience. Waking up to discover that your family has disappeared and been replaced by duplicates, aliens or robots is perhaps somewhat more unsettling – for you, and for the family you no longer acknowledge as your own.
While delusions are by definition uncommonly strange beliefs, the Capgras delusion is certainly among the more bizarre. Sufferers declare that the person standing before them, while admittedly identical in appearance and behaviour to a relative or friend, is nevertheless an imposter. Named after the French psychiatrist who provided the first detailed case description in 1923, the delusion usually involves the “replacement” of a family member or close friend by a duplicate; in at least one case the missing loved one was a dog, and even inanimate objects have been believed to have been replaced by duplicates.
Capgras syndrome is one of several “delusional misidentification syndromes”, which are characterised by the presence of a single, specific delusion concerning false identity or substitution of one person for another. In contrast to psychotic disorders in which a diversity of delusions are often present, these misidentification syndromes contain a single delusion, or several delusions clustered around a single theme.
While earlier psychodynamic theories had...
