Parents drill certain warnings into their children: don't drink, don't smoke and don't do drugs. But those conversations have gotten tougher now that two states, Colorado and Washington, have decriminalized some recreational marijuana use.
Opportunists who market street drugs may be undermining the global struggle against AIDS.
In South Africa, two mainstay HIV drugs have found their way into recreational use. That may help explain why some HIV patients are resistant to these front-line medicines even if they've never been in treatment before.