Denial

An unconscious mental process that serves as a psychological barrier to either protect or defend the ego from external reality constructs. In some instances, it is viewed as an adaptive, healthy form of self-deception that offers the client time to absorb information or experiences. In others, it is seen as maladaptive and is the hallmark of disease such as alcoholism or the failure to seek treatment when treatment is needed.

Reference:
Wheeler, S., & Lord, L. (1999). Denial: A conceptual analysis. Archives of Psychiatric Nursing, 13(6), 311-320. https://doi.org/10.1016/S0883-9417(99)80063-6