In psychology (and also psychiatry), depersonalization (or derealization) is the experience of feelings of loss of a sense of reality. A sufferer feels that he or she has changed and the world has become less real -- it is vague, dreamlike, or lacking in significance. The DSM-IV categorizes depersonalization disorder as a form of dissociative disorder, though depersonalization proper is more often characteristic of the traumatic origin of other conditions.

Sufferers of depersonalization feel divorced from both the world and from their own identity and physicality. Often times the person who has experienced depersonalization claims that life "feels like a movie, things seem unreal, or hazy." [citation needed] Also a recognition of self breaks down (hence the name). When a person suffers from the disorder (or the symptoms associated with it) he or she finds that when looking in the mirror, his or her face is not familiar, though logically he or she is completely aware of his or her identity.

The feeling is said to be like being a ghost. No matter how hard the person tries, he/she cannot feel like they are genuinely interacting with the world and can't seem to perceive themselves as being normal. They feel like they are trapped between the real world and death. While one is struggling so hard to feel everything as normal again, there is a part of oneself which begs to just give up and stop the struggling. Simply put, it is an alteration in the perception or experience of oneself, so that the self is felt to be unreal; the person feels detached from the reality or their own body or mental processes