Experts pinpoint the increase in heroin abuse to an increase in prescription opioid painkillers. Sales of prescription opioids in the U.S. nearly quadrupled from 1999 to 2014.
Twelve states, including Ohio, Kentucky and Indiana, have more prescriptions for opioid painkillers than people.
Long-term use of opioid pain relievers can lead to abuse and overdose on prescription painkillers. Since heroin is cheaper than prescription opioids, people addicted to painkillers often switch to heroin.