This article is from the Dissociation FAQ, by Discord (firstname.lastname@example.org) with numerous contributions by others.
Depersonalization disorder is either a persistent or recurring alteration
in one's perception of one's self, such as a feeling of detachment from
one's actions or thoughts, or feeling like an observer of one's own
actions. Alternatively, one may feel as if one is an automaton, without
conscious will of one's actions, or feel as if one is dreaming, rather
than actually performing, one's actions.
Depersonalization Disorder is caused by severe stress; it is not
uncommon to have a single instance of depersonalization (but this is
usually not recurrent or persistent) due to stress. It is usually found
in younger adults (late adolescence/early adulthood).
Depersonalization may be accompanied by derealization, the alteration of
one's perception of one's surroundings, which leads to the feeling that
the world is not real. It is sometimes also accompanied by dizziness,
depression, anxiety, or other similar disorders.
Differential Diagnoses include many mood disorders, organic disorders,
anxiety disorders, personality disorders, and schizophrenia. Although
not listed in the DSM-III-R as a differential diagoisis, MPD may have