ISLAM QALA, Afghanistan — The addicts stalk the streets of this border post like hollowed-out skeletons, hair matted by filth and eyes glassy. The villages that hug the roads are veritable zombie towns, where families of men, women and children hide their addiction within barren mud compounds.

“Sometimes I feel it is better to die than live like this,” said Haidar, 30, seated on the floor of his living room beside a small tin of sugarlike powder.

His family, a wife and young children, bore the gaunt faces of addiction as well.

In western Herat Province, held up as an island of stability and progress in Afghanistan, this forlorn border town is instead a showcase for an intensifying crisis: Long the global leader in opium production, Afghanistan has now also become one of the world’s most addicted societies.

The number of drug users in Afghanistan is estimated to be as high as 1.6 million, or about 5.3 percent of the population, among the highest rates in the world. Nationwide, one in 10 urban households has at least one drug user, according to a recent report from the Bureau of International Narcotics and Law Enforcement Affairs. In the city of Herat, it is one in five.