As documented elsewhere on wiki, the route to most current heroin abuse is not recreational use, but painkiller addiction:
According to statistics from the Center for Disease Control, drug use researchers like Kolodny, and even the DEA, what gets people addicted to heroin in places like New Hampshire and Vermont is the over-prescription or ready availability of painkillers like Percocet, OxyContin and Vicodin. When users can’t wean off the drug effectively, they turn to cheaper alternatives, like heroin.
This has immediately deleterious effects, as often upstanding people are then treated like criminals and refuse to seek help in fear of prosecution, which can often end in death.
Opiate-related deaths have quintupled in the state in the last two years.
“There aren’t a lot of people saying, ‘Hm, heroin sounds like a fun drug to try!’ The people who are using heroin are people who have opioid addiction,” said Kolodny, who is also a senior scientist at Brandeis University’s Heller School for Social Policy & Management. “Some develop [a painkiller addiction] for taking drugs exactly as they were prescribed.” (Source)