Yes. It happens with PTSD.

Depersonalization refers to the experience of feeling detached from one's own life as thought what you are living and experiencing is a dream or movie that you are watching from the outside. It is often a reaction to trauma and can be one of the symptoms of Post Traumatic Stress Disorder.

Depersonalization/Derealization Disorder
The distinguishing characteristic of depersonalization disorder is the feeling that one is disconnected or unreal. Mind or body may be perceived as unattached, seen from a distance, existing in a dream, or mechanical.

Chronic depersonalization is commonly accompanied by "derealization," the feeling that features of the environment are illusory.

It should be noted that depersonalization as an isolated symptom may appear within the context of a wide variety of major psychiatric disorders like schizophrenia, borderline personality disorder, panic disorders and even depression.

Read more.
http://forums.psychcentral.com/showthread.php?t=89088