Depersonalization is an anomaly of the mechanism by which an individual has self-awareness. It is a feeling of watching oneself act, while having no control over a situation. Sufferers feel they have changed, and the world has become less real, vague, dreamlike, or lacking in significance. It can be a disturbing experience, since many feel that, indeed, they are living in a "dream". Chronic depersonalization refers to depersonalization disorder

Depersonalization disorder

Depersonalization disorder is a dissociative disorder in which the sufferer is affected by persistent or recurrent feelings of depersonalization and/or derealization. Diagnostic criteria include persistent or recurrent experiences of feeling detached from one's mental processes or body...

, which is classified by the DSM-IV as a dissociative disorder.