This article is from the Bipolar Disorder FAQ, by firstname.lastname@example.org (Barry Campbell) with numerous contributions by others.
Most certainly. The DSM-IV (p. 766) defines a hallucination as:
A sensory perception that has the compelling sense of
reality of a true perception but that occurs without
external stimulation of the relevant sensory organ.
Hallucinations should be distinguished from illusions, in
which an actual external stimulus is misperceived or
Some people know that they are having hallucinations, and others do not. Most
people who have bipolar disorder realize that the hallucinations are not actual
perceptions of reality. However, this realization does not keep them from