Afghanistan, the world's biggest heroin producer, is struggling to cope with a drug problem as thousands of Afghans - trying to cope with the traumas of war, displacement and poverty - are becoming addicted to narcotics.
On the outskirts of Kabul, a sprawling bombed-out building that was once a centre for culture and science is home to over 100 squatters whose main concern is feeding their heroin habit.
Ghulam Ahmad, a 17 year-old addict, has been injecting heroin for almost two years now. Like many living in the squalid, filthy building, he started using drugs in neighbouring Iran. "I used to work nights in a factory in Iran, and the factory owner, an Iranian man, was addicted to opium himself," he said.
Later, Ahmad moved onto heroin, before being deported back to his native Afghanistan. He now spends his days begging on the streets of Kabul to feed his habit.
Afghanistan produced some 8,200 tonnes of opium in 2007, or 93 percent of the world's supply. More land is used to cultivate drugs in Afghanistan than Bolivia, Colombia and Peru combined, the United Nations says.
In the past, opium was smuggled abroad from Afghanistan and then processed into heroin before it hit the streets of Europe, the Indian sub-continent and the Middle East. But now the problem is coming home. In recent years, Afghan drug lords have sought to maximise profits by processing opium into heroin at home before sending it abroad.
Some drugs inevitably remain inside the country where there is a ready market for heroin due to the high rate of drug use among the hundreds of thousands of Afghan refugees returning or deported from neighbouring Iran and Pakistan.
The rates of addiction in Afghanistan have increased sharply since 2003 to nearly 4 percent of the population, the UN says. There are now roughly 150,000 opium users, 50,000 heroin addicts and 520,000 cannabis smokers. Of those 120,000 are women and 60,000 are children.
"Decades of war, poverty, unemployment, post-war trauma and the availability of a variety of drugs in Afghanistan have created tens of thousands of young Afghan drug addicts," said Jehanzeb Khan, of the United Nations Office on Drugs and Crime (UNODC) in Afghanistan.
"Most of them are deportees from neighbouring countries - Iran and Pakistan," he said. Mohammad Bashir, 24, who also lives in the Russian-built former cultural centre has been addicted to heroin for more than seven years. He was recently deported from Iran.
"I was a good tailor, I used to work very hard. In order to (get) relief from my load of work, I used to either smoke or eat opium as a pain killer every day," he said scratching his face with both hands. "I don't know if I can get out this misery."
"My daily spending on heroin is about 200 afghanis ($4). I have to manage to find it by all means," he said. "If I don't get the money, my entire body will be in severe pain."
According to Afghan drug analysts, 98 percent of Afghan drug addicts do not have jobs and find money for drugs through begging or loading and unloading goods from trucks in nearby markets. Most Afghans, struggling to make a living themselves, look down on drug addicts and refuse to give them money, thinking it will fuel their addiction.
"People usually don't give us jobs, money or food, because drug addiction is one of the worst habits the normal people can think of," Bashir said. "This evil habit will never let me work until I die." There is some help for available addicts in Afghanistan, but in a country ravaged by 30 years of war there are many other demands on the government's small budget and limited amounts of international aid.
Around 39 foreign-supported centres treating drug addicts in Afghanistan. Zendagi Naween - or New Life - is a British-funded Afghan organisation that has been helping Afghan drug addicts since 2003 in three provinces through community and drug demand-reduction centres.
But its treatment centre in Kabul has only 10 beds despite a long waiting list of drug addicts, especially heroin users, the centre's director Dr Naseemullah Bawar explained.
"(To) rid the (patients) of the drug needs from their body, we need to keep them in the bed for 28 days," he said. "The number of drugs users is rising dramatically everyday," he added. "We need more assistance to build more centres to help these people."
Ekhtiar Gul, an Afghan heroin addict, is one of the lucky ones as he is receiving treatment in Zendagi Naween. "I can feel a big difference in me and after my treatment is complete, I will start a new life ... drug free," he said. But Gul's optimism may be misplaced.
"Some 70 percent of treated drug users go back to drugs due to joblessness, stress and having no proper family or community support," said Khan, of the UNODC. "When someone is a heroin addict he is cursed for his whole life."