Katya Nikitina could not sleep, think, or move during her first seven days at the rehab clinic.
A heroin addict in the Urals in western Russia, she moved from Chelyabinsk to the facility in Yekaterinburg, the area's main urban centre, to get clean.
"It's hard to think back to that time. You can't sleep, sit, or stand from the pain, you just walk around in the dark, bumping into furniture," she recalled.
Like all the addicts there, she was locked in a small room with a barred window and was kept on a diet of bread, porridge, and onions, for a month-long "quarantine" period.
Today, Katya, 28, is one of three dozen girls living in the rehab centre set up by the City Without Drugs, a foundation that is unique in Russia -- whose harsh methods have gained support in a country worried about soaring drug addiction.
Unusually, it combines a cold-turkey coercion method of rehab and a dealer-busting operations unit. It is private and has no links to the powerful Russian Orthodox Church.
Heroin now accounts for less than half of Russia's illegal drugs, says organisation head Evgeny Roizman. But new drugs are harder to catch and are even more destructive, targeting increasingly younger Russians.
Russia's drug control agency estimates that there are about five million drug users in the country, and while drug deaths are not well documented, there are about 100,000 deaths annually among 15 to 30-year-olds, the age-group of heaviest use.
Drug-related deaths are also worsening the country's population decline since the fall of the Soviet Union, and Russia has long been criticised by international groups for failing to properly combat the problem.
"Right now the government's policies are ineffective," Roizman said of Russia's drug problem. "There is no political will. The government's main task is to keep its population, and they are failing at it."
-- 'We have treated 9,000 people' --
Roizman has turned into a local celebrity and readily defends his approach, which many criticise as brutal and ineffective.
"Throughout our 12-year history, 10 people showed up for rehab on their own accord. Others are brought by parents, in car trunks, even in chains -- we've seen it all," he said.
"But we have treated 9,000 people, and more than half of those do not use (drugs) today. An addict cannot think for himself, it's pointless to wait for him to want to stop."
Essentially, the foundation's rehab provides a drug-free environment and group counselling for up to a year for a modest 8,000 rubles ($270) per month, in the hopes the addict will be strong enough not to return to drug use after going home.
But there is no formal follow-up procedure, and the non-governmental organisation only knows about those rehab graduates who choose to stay in touch.
About 15 such people are now employed as operatives, who monitor illegal drug activity at their assigned districts in the Yekaterinburg area and work along with police to bust dealers.
"A policeman who has never been an addict has a hard time working on drug cases," said Mikhail Polutorny, a former heroin user who has been clean for several years. "He won't see the drug-related movement on the streets, he won't be able to tell if someone is a junkie."
Polutorny came to the rehab from Israel, where he says he tried expensive rehabilitation clinics. He now zips around in an old car with three phones, and locals call him to report suspicious activities or the telltale smell given off by the cooking and preparation of illicit drugs.
-- 'Crocodile' can kill an addict in a year --
Weekly videos the foundation films show the dirty pots, piles of medicine wrappers and syringes filled with brown liquids strewn around drug den kitchens in the Yekaterinburg area.
Emaciated young people covered with body sores tell the camera who they are and how long they have been shooting up desomorphine, nicknamed "krokodil" (crocodile) for its effects on the skin. Some turn away. The energetic voiceover calls them 'reptiles'.
A scourge among the lower-class in Russian regions, "crocodile" has practically replaced heroin in Yekaterinburg. But made of drugs containing codeine and highly toxic by-products, it can kill an addict within one year.
"To inject twice, four people need only 300 rubles ($11) each," former user 18-year-old Sasha Yankovskaya said sitting at the rehab centre. "I was losing my hair, my teeth."
All "crocodile" users at the rehab centre are HIV-positive.
Those who are far-gone basically rot from multiple abscesses, their immune system broken. The cause of death consequently is not directly due to a drug overdose, which makes it next to impossible to estimate the scope of the problem. The average age of users is 27.
Even younger are users of JWH, or synthetic cannabis, which flooded Russia and created a huge market among teenagers before it was banned in 2010, Roizman said.
"The government understands very well that in Russia, drugs are a number one problem, this is why our nation is dying out," Katya Nikitina said, sitting at the rehab house kitchen with a glass of homemade juice.
"I don't understand why they ignore this problem, maybe they stand to profit from it? There should be more rehab centres like this than regular clinics, it's ideal because there is no religious aspect to it."
A proponent of tough anti-drug policies, Roizman recently allied with billionaire Mikhail Prokhorov, who ran for president against Vladimir Putin, and says that officials detest him because he calls things what they are.
But sometimes the truth hits right back at him: soon after the visit by AFP, one of the foundation's success stories and office assistant, Denis, ran away to shoot "crocodile".
He was found after four days with ghastly sores on his neck from the injections. His photos were up on Roizman's blog right away: "He spat into our souls," he wrote bluntly. "We began again."