Wow, multiple personality? Your psychologist was clueless. I mean, taking base rates into consideration, that diagnosis is bordering on absurd.

It sounds like you are having dissociative episodes; it could be depersonalization disorder, but it doesn't seem to be causing "significant distress or difficulties", which is one of the DSM IV criteria.

DSM-IV-TR criteria 1. Longstanding or recurring feelings of being detached from one's mental processes or body, as if one is observing them from the outside or in a dream.

1. Reality testing is unimpaired during depersonalization

2. Depersonalization causes significant difficulties or distress at work, or social and other important areas of life functioning.

3. Depersonalization does not only occur while the individual is experiencing another mental disorder, and is not associated with substance use or a medical illness.

The DSM-IV-TR specifically recognizes three possible additional features of depersonalization disorder:

1. Derealization, experiencing the external world as strange or unreal.
2. Macropsia or micropsia, an alteration in the perception of object size or shape.
3. A sense that other people seem unfamiliar or mechanical.

[edit] Etiology