<unk>  (DR) is an alteration in the perception or experience of the external world so that it seems strange or unreal. Other symptoms are feeling as though one's environment is lacking in spontaneity, emotional colouring and depth.  .  It is a dissociative symptom of many conditions, such as psychiatric and neurological disorders, and not a standalone disorder. It is also a transient side effect of acute drug intoxication, sleep deprivation and stress.
Depersonalization is a subjective experience of unreality in one's sense of self, while<unk>  is unreality of the outside world.  Depersonalization and<unk>  are often used interchangeably, although evidence suggests they have distinct neurobiological mechanisms.  Chronic<unk>  may be caused by occipital-temporal dysfunction.
These symptoms are common in the population, with a lifetime prevalence of up to 74% and between 31-66% at the time of a traumatic event.
Derealization
Aversion to happiness
Depersonalization
Virilization
Dissociation 
Perseveration
Exaptation
Impaction