U.S. Secretary of State John Kerry talks with Afghan presidential candidate Abdullah Abdullah at the start of a meeting at the U.S. Embassy in Kabul on Friday. Kerry sought Friday to broker a deal between Afghanistan's rival presidential candidates. Jim Bourg/AP hide caption

itoggle caption Jim Bourg/AP

Bryan McDonel and his father, Mike, both served multiple tours in Iraq with the National Guard. Bryan was first prescribed painkillers before his deployment, and his dependence on medication prompted a downward spiral. Quil Lawrence/NPR hide caption

itoggle caption Quil Lawrence/NPR