Parkinson’s Disease Psychosis Fact Sheet

What is Parkinson’s disease? Parkinson’s disease (PD) is a chronic and progressive neurodegenerative disorder characterized by the loss of dopamine-producing brain cells. Common motor symptoms of PD include tremors, limb stiffness, slowness of movement and impaired balance/coordination.i Common non-motor symptoms of PD include psychosis, depression, sleep impairment, and dementia.

How many people are affected by Parkinson’s disease? Parkinson’s affects about one million people in the United States and between four to six million people globally. It is the second most common neurological disorder after Alzheimer’s disease. ii

What is Parkinson’s disease psychosis? Parkinson’s disease psychosis (PDP) is a debilitating disorder that commonly consists of hallucinations and delusions. Hallucinations are more common and often are visual. Research has shown that delusions often involve suspicions of spousal infidelity or other paranoid themes and are often disturbing and debilitating to patients.iii

PDP substantially contributes to the burden of Parkinson's disease and deeply affects a patient's quality of life. PDP is also associated with increased caregiver distress and burden, nursing home placement, and increased morbidity and mortality.iii

What causes Parkinson’s disease psychosis? Though PDP was historically thought to be a side effect of dopaminergic therapy, a causal relationship has not been established. PDP may be more related to progression of the underlying disease.

Do all Parkinson’s disease patients experience PDP? PDP occurs in about 40 percent of patients with Parkinson’s disease. The onset of psychosis in Parkinson’s patients is generally considered a poor prognostic sign.

What is the current treatment for PDP? Currently, no drug is approved to treat PDP in the United States. The condition is often treated with atypical antipsychotics, which can worsen the symptoms of Parkinson’s disease and carry a black box warning for use in elderly patients with dementia-related psychosis due to increased morbidity and mortality. ACADIA Pharmaceuticals is developing NUPLAZIDTM (pimavanserin), a selective serotonin inverse agonist preferentially targeting 5-HT2A receptors, as a potential first-in-class treatment for PDP. Outcomes from NUPLAZID’s successful Phase III clinical trial, referred to as the -020 Study, suggest that NUPLAZID has the potential to provide a safe and effective treatment of psychosis without compromising motor control. Results of the -020 Study were published in The Lancet.

i National Institutes of Health (NIH) National Institute of Neurological Disorders and Stroke. (2014, August). NINDS Parkinson's Disease Information Page. Retrieved August 18, 2014, from http://www.ninds.nih.gov/disorders/parkinsons_disease/parkinsons_disease.htm ii National Parkinson Foundation. Retrieved August 20, 2014, from http://www.parkinson.org iii Schrag A, Hovris A, Morley D, Quinn N, Jahanshahi M. Caregiver-burden in Parkinson's disease is closely associated with psychiatric symptoms, falls, and disability. Parkinsonism and Related Disorders. 2006 Jan;12(1):35-41. Epub 2005 Nov 3. Retrieved August 21, 2014, from http://www.ncbi.nlm.nih.gov/pubmed/16271496