Pimavanserin vs. Quetiapine for Treatment of Parkinson's Psychosis

Inclusion Criteria:

• Veteran

• Age 40 years or older

• Diagnosis of Parkinson's Disease consistent with UK Parkinson's Disease SocietyBrain Bank Clinical Diagnostic Criteria

• Psychosis [with Neuropsychiatric Inventory (NPI) hallucinations (B) or delusions (A)score 4 or greater]

• Stable dose of PD medications for at least 1 month

• If on an acetylcholinesterase inhibitor (AChEI) initially prescribed at least 3months prior and stable dose (no dose or medication change) for past month

• Informed other must provide informed consent and agree to attend all study visits.The informed other must be at least 18 years of age and have regular in-personcontact with the patient (at least 5 days per week, and at least 4 hours per daythat is spent with patient)

• English-speaking

INFORMED OTHER

• Age 18 years or older

• Must have regular in-person contact with the patient (on average at least 5 days perweek, and at least 4 hours per day that is spent with patient)

• Agree to attend all study visits

• Be able to provide informed consent

• English-speaking

Exclusion Criteria:

• Psychosis symptoms severe enough to preclude enrollment in a clinical trial andrequire prompt clinical care instead

• Treatment with an antipsychotic, including pimavanserin in the past year, exceptquetiapine <50 mg/day which has been discontinued for at least 1 month prior tostudy randomization

• Deep brain stimulation (DBS) surgery occurring within 6 months prior or has hadstimulator adjustments in the previous month

• History of a psychotic disorder prior to PD, including schizophrenia and bipolardisorder

• Suspected atypical parkinsonian disorder or dementia with Lewy bodies (DLB)

• Psychosis secondary to other toxic or metabolic disorder

• History of long QT syndrome

• Prolonged QTc [>450ms in men, >470ms in women] at screening

• History of ventricular arrhythmias, or untreated or unstable atrialfibrillation/flutter

• Currently taking medications that are moderate or strong CYP3A4 inducers or strongCYP3A4 inhibitors

• Concomitant use of drugs that prolongs the QTc interval

• Comorbid medical condition determined too severe by SI to allow participation inclinical trial

• Failure to tolerate quetiapine or pimavanserin previously

• Moderate to severe PD dementia (MoCA score <13)

• Currently enrolled in another therapeutic or interventional study

• Nursing home placement at screening or planned placement during the study

• Active suicidality

• Pregnant, or a female of child-bearing potential who is unwilling to use a reliableform of contraception