Heroin and opium are two of the world's most addictive drugs, and now they have come back to haunt Afghanistan, the country that produces almost all the global supply.

The United Nations says Afghanistan produces 90 per cent of the world's opium, most of which goes to Europe and the United States.

But the country is also becoming a major consumer of heroin, with just a handful of clinics and little community support for opiate users - estimated to be as many 1.5 million.

Al Jazeera's Bernard Smith reports from Kabul.