Historic decline in U.S. overdose deaths threatened by changing street drug supply

Drug overdose deaths are plummeting in the U.S. in ways never seen before. Experts worry new, toxic "synthetic" street drugs could derail the recovery.

Drug overdose deaths are plummeting in the U.S. in ways never seen before. Experts worry new, toxic "synthetic" street drugs could derail the recovery.

(Image credit: Mark Schiefelbein/AP)