Abstract

Déjà vu is a familiar phenomenon in neurology psychiatry, and everyday life. Assessment of its significance is helped by an acquaintance with the ambiguities of the term, and with the epidemiology, disease associations and physiology of the experience.

WHAT IS DÉJÀ VU?

Déjà vu means, literally, ‘already seen’. In colloquial English it is often used indiscriminately to refer to familiar events and experiences. In its more technical or medical context it refers to the disconcerting sense that one’s current experience is familiar when, in fact, it is novel. This phenomenon has been described repeatedly in literature, for example by Charles Dickens:

‘We have all some experience of a feeling which comes over us occasionally, of what we are saying or doing having been said or done before, in a remote time – of our having been surrounded, dim ages ago, by the same faces, objects and circumstances – of our knowing perfectly