SAN DIEGO--(BUSINESS WIRE)--ACADIA Pharmaceuticals Inc. (Nasdaq: ACAD), a biopharmaceutical company utilizing innovative technology to fuel drug discovery and clinical development of novel treatments for central nervous system disorders, today announced that it has initiated a new Phase III trial designed to evaluate the efficacy, tolerability and safety of pimavanserin as a treatment for patients with Parkinson’s disease psychosis (PDP).