Psychosis in Neurodegenerative Disease.
Psychosis has been recognized as a common feature in neurodegenerative disease for many years. Hallucinations, delusions, and other psychotic phenomena occur in a wide range of degenerative disorders including Alzheimer disease, Huntington disease, Parkinson's disease, diffuse Lewy body disease, "Parkinson plus" syndromes, Pikc's disease, and other frontotemporal degenerations, amyotrophic lateral sclerosis, and prion associated diseases. It is also interesting that neurodegenerative disease-type dementia may be a feature in some psychotic illnesses such as schizophrenia. Clinical evaluation of psychosis in the setting of dementia presents a significant challenge for clinicians and researchers. Amnesia, language or speech impairments, and behavioral problems amy distort and obscure the presentation of symptoms. However, recognition and understanding of the psychotic manifestations may lead to the institution of more effective therapeutic or preventive options that can serve to delay long term care placement and improve patient and caregiver quality of life. In addition, a more comprehensive understanding of the pathophysiology, neuroanatomical substrates, and distinctive pathological features underlying the development of psychotic symptoms in neurodegenerative diseases may provide important insights into psychotic processes in general.