Denial, in ordinary English usage, is asserting that a statement or allegation is not true.[1] The same word, and also abnegation, is used for a psychological defense mechanism postulated by Sigmund Freud, in which a person is faced with a fact that is too uncomfortable to accept and rejects it instead, insisting that it is not true despite what may be overwhelming evidence.[2][3]

The subject may use:

simple denial: deny the reality of the unpleasant fact altogether minimisation: admit the fact but deny its seriousness (a combination of denial and rationalization) projection: admit both the fact and seriousness but deny responsibility by blaming somebody or something else.
The concept of denial is particularly important to the study of addiction. The theory of denial was first researched seriously by Anna Freud. She classified denial as a mechanism of the immature mind, because it conflicts with the ability to learn from and cope with reality. Where denial occurs in mature minds, it is most often associated with death, dying and rape. More recent research has significantly expanded the scope and utility of the concept. Elisabeth Kübler-Ross used denial as the first of five stages in the psychology of a dying patient, and the idea has been extended to include the reactions of survivors to news of a death.

Many contemporary psychoanalysts treat denial as the first stage of a coping cycle. When an unwelcome change occurs, a trauma of some sort, the first impulse to disbelieve begins the process of coping. That denial, in a healthy mind, slowly rises to greater consciousness. Gradually becoming a subconscious pressure, just beneath the surface of overt awareness, the mechanism of coping then involves repression,