A Study of the Safety and Efficacy of Pimavanserin (ACP-103) in Patients With Parkinson's Disease Psychosis

Inclusion Criteria: * A clinical diagnosis of Parkinson's disease with a minimum duration of 1 year * Presence of visual and/or auditory hallucinations, and/or delusions, occurring during the four weeks prior to study screening * Psychotic symptoms must have developed after PD diagnosis was established * Subject must be on stable dose of anti-Parkinson's medication for 1 month prior to Study Day 1 (Baseline) and during the trial * Subject that has received stereotaxic surgery for subthalamic nucleus deep brain stimulation must be at least 6 months post surgery and the stimulator settings must have been stable for at least 1 month prior to Study Day 1 (Baseline) and must remain stable during the trial * The subject is willing and able to provide consent * Caregiver is willing and able to accompany the subject to all visits Exclusion Criteria: * Subject has a history of significant psychotic disorders prior to or concomitantly with the diagnosis of Parkinson's disease including, but not limited to, schizophrenia or bipolar disorder * Subject has received previous ablative stereotaxic surgery (i.e., pallidotomy and thalamotomy) to treat Parkinson's disease * Subject has current evidence of a serious and or unstable cardiovascular, respiratory, gastrointestinal, renal, hematologic or other medical disorder * Subject has had a myocardial infarction in last six months * Subject has any surgery planned during the screening, treatment or follow-up periods Patients will be evaluat…