http://www.psychologytoday.com/blog/...ersonalization

{quote} Depersonalization is often categorized as a reaction. The DSM-IV conceptualizes DP as a dissociative disorder, and dissociation is a typical response to trauma. The DSM-IV also lists DP as an element of posttraumatic stress disorder and considers DP as a coping style. At the same time, depersonalization is understood as a personality trait— a constitutional predisposition to develop depersonalization that once was named “depersonability.” People with “depersonability” are prone to subclinical micro-depersonalization: momentarily but distinctive episodes of estrangement, especially pronounced during adolescence. They often develop a flourishing depersonalization-reaction in response to emotional trauma, physical stress or use of psychoactive substances. In many cases symptoms of depersonalization combines properties of DP-reaction and DP-personality trait. During some periods presentations of depersonalization-reaction prevail, during other periods signs of depersonalization-personality trait dominate.
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