Which disorder is characterized by experiences of unreality or detachment regarding surroundings?

Derealization is characterized specifically by experiences of unreality or detachment from one’s surroundings. Individuals with this disorder often perceive the world around them as distorted or dreamlike, feeling as though they are observing their environment from a distance rather than engaging with it normally. This symptom can be mild or severe and often leads to significant distress or impairment in functioning.

In contrast, the other disorders listed do not primarily focus on the experience of unreality regarding one's environment. Major Depressive Disorder is primarily marked by persistent sadness, hopelessness, and a lack of interest in activities, rather than detachment from surroundings. Dissociative Identity Disorder involves the presence of two or more distinct personality states and does include dissociation but focuses more on identity and memory rather than perception of surroundings. Body Dysmorphic Disorder centers on obsessive preoccupation with perceived flaws in one’s physical appearance, which is unrelated to experiences of unreality regarding the environment.