​​TEHRAN — Just south of Tehran’s sprawling central bazaar lies a poor neighborhood called Davarze Ghar, or the "entrance to the cave," known locally for drugs and stolen goods. Groups of men and veiled women huddle together around an empty reservoir smoking the noxious amphetamine crystal meth or injecting crack, a processed form of heroin unique to the Islamic Republic.

A line of schoolgirls dressed in smart white and pink uniforms with matching plastic Barbie rucksacks are led past the reservoir by their watchful teacher, clad in a long black chador. Police on motorbikes pass by regularly but do not stop.

“In Tehran, meth is more available than bread,” says Abolfazl, a young man (whose name has been changed along with all the others') in military service fatigues, crouching against the only painted wall in the neighborhood: a huge, brightly colored mural honoring a martyr of Iran’s long war with Iraq. “There’s nothing do here. We smoke meth to forget ourselves.”

The World Drug Report frequently cites Iran as having one of the highest levels of heroin addiction in the world. Officially, Iran has 2 million drug addicts but experts agree that the real figure is significantly higher. The country’s position along the Afghanistan-Europe heroin trafficking routes and stigma among its poorer communities around alcohol are oft-cited reasons for Iran’s centuries-old drug problem. But rising unemployment, high inflation and a currency that has lost over half its value since sanctions were placed on Iran at the start of 2011 have compounded the crisis.