Why the new drug for Alzheimer's disease is causing controversy

The U.S. Food and Drug Administration gave "accelerated approval" this month to the first new drug to treat Alzheimer's disease in nearly two decades. But there is controversy over the efficacy of the drug, as well as its cost and side effects. Saska Sivananthan, chief of research and knowledge translation for the Alzheimer Society of Canada, breaks down what we know so far about the drug.