Denial, the refusal to acknowledge painful reality, is considered to be a very primitive mechanism of defense derived from early childhood. There is that state during the first year of the child's life in which an object removed from direct perception ceases to exist for the child.1,2 It is suggested that in the act of denying, the perception of a disagreeable object is actively rejected in the hope that the ancient sequence will be repeated and the object will cease to exist. The ostrich with its head in the sand is the proverbial symbol of denial.
Since the denial mechanism stems from a very early developmental stage, it is perhaps not surprising that when frank denial is seen to any appreciable degree in adults, it is in association with serious mental illness. As an example, in postpartum psychosis the patient may deny all knowledge of pregnancy or
HANKOFF LD, ENGELHARDT DM, FREEDMAN N, MANN D, MARGOLIS R. Denial of Illness in Schizophrenic Outpatients: Effects of Psychopharmacological Treatment. Arch Gen Psychiatry. 1960;3(6):657-664. doi:10.1001/archpsyc.1960.01710060089013