hallucination

n. A sensory perception in the absence of any external stimulus. Hallucinations can be auditory, visual, tactile, olfactory, or gustatory; auditory hallucinations are by far the most common. Hallucinations are most commonly seen in the psychotic disorders, specifically schizophrenia, although they can be found in severe cases of bipolar disorder, major depressive disorder, substance abuse and dependence (including alcohol and stimulant abuse and dependence), and occasionally borderline personality disorder.

- DGa