After an incredible performance in late March, when shares of Acadia Pharmaceuticals (ACAD -1.05%) jumped up 23%, they have once again exploded today, up 40% intraday. What's behind these massive leaps for this pharmaceutical company, and is there more on the way? In this video, Motley Fool health-care analyst David Williamson tells investors about the drug that has Acadia investors so excited, why it has so many competitive advantages, and what investors need to watch from here.