Derealization is an alteration in the perception of the external world, causing those with the condition to perceive it as unreal, distant, distorted, or in other ways falsified. Other symptoms include feeling as if one's environment lacks spontaneity, emotional coloring, and depth. Described as "Experiences of unreality or detachment with respect to surroundings " in the DSM-5, it is a dissociative symptom that may appear in moments of severe stress.