The Alzheimer’s economy: is the new $56,000-a-year drug worth it?

People around the world are waiting for their infusion of hope.
 The US approval of Biogen's Alzheimer’s treatment has given patients the belief that there is some way of combatting the debilitating disease. Sarah Neville, Hannah Kuchler and Nikou Asgari explore how a varied range of problems hint that health services will struggle to live up to the drug's promises.