HALLUCINATION
Hallucinations are defined as a perception of and external object when no object is really present.
The false perceptions can occur in any of the five sensory modalities. Therefore, a hallucination essentially is seeing, hearing, tasting, feeling, or smelling something that is not there. The false perceptions are not accounted for by the person's religious or cultural background, and the person experiencing hallucinations may or may not have insight into them. Therefore, some people experiencing hallucinations may be aware that the perceptions are false, whereas others may truly believe that what they are seeing, hearing, tasting, feeling, or smelling is real. In cases when the person truly believes the hallucination is real, the individual may also have a delusional interpretation of the hallucination.
CAUSES:
There are many causes of hallucinations, including:
- Being drunk or high, or coming down from such drugs as marijuana, LSD, cocaine (including crack), PCP, amphetamines, heroin, ketamine, and alcohol
- Delirium or dementia (visual hallucinations are most common)
- Epilepsy that involves a part of the brain called the temporal lobe (odor hallucinations are most common)
- Fever, especially in children and the elderly
- Psychiatric disorders, such as schizophrenia and psychotic depression
- Sensory problem, such as blindness or deafness
- Severe illness, including liver failure, kidney failure, AIDS, and brain cancer
