The direct causes of Alzheimer's disease continues to elude the scientific community, which makes creating treatments for it exceedingly difficult. We have seen a number of high-profile failures lately, and now Baxter International can be added to that list. Shares were down slightly, as drug Gammagard failed to preserve or reduce the decline of cognitive function in patients during phase 3 trials.

In this video, health-care analyst David Williamson discusses what's next for Baxter and other promising drugs to treat Alzheimer's that investors need to have on their radars.

Follow David on Twitter: @MotleyDavid.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.