ASIF (not his real name) was a successful salesman, with a smart suit and company car, when he started injecting heroin to cope with his personal problems.
But after five years, the 32-year-old was determined to quit, having been sucked into a life of petty crime and drug-pushing.
A year after walking into Hounslow's Drugs Advice Intervention and Skills centre (DAIS) - and after a number of false starts - he has been clean for nearly two months and describes it as the best decision he has made.
"I don't think I could have done it without this place," he said. "The staff are so friendly and they understand your problems because they've seen other people going through the same thing. They're only a phone call away if you think you're going to use again.
"When I first came I thought 'it's a drugs place, you're going to be judged', but it's not like that at all."
Asif (pictured) is just one of many success stories at DAIS, in Alexandra Road, which has gradually built up a word-of-mouth reputation thanks to its confidential, nonjudgmental and friendly approach to tackling drug abuse.
The centre is open to anyone who lives or works in Hounslow.
Although a handful of clients are referred by GPs or social workers, about 95 per cent go there voluntarily.
Team leader Theresa Young describes it as a 'stepping stone' for addicts, who can drop in at any time during office hours for an on-the-spot assessment.
The small team of experienced drug workers create a personalised action plan before referring users to other services, from counselling to housing support.
As well as offering support and advice, they provide a range of services on-site, including a needle exchange to ensure users can inject safely, and acupuncture to help curb cravings.
Addicts can use the needle exchange anonymously and there's even a £5 Asda voucher as a reward when they return their 10th set of needles. But most people don't get that far, explains Theresa.
"Usually they're in treatment before that point," she said. "We don't pressure them. It's all about building up trust. After a few visits they feel like they can talk to us and they know we're here to help.
"People might come in two or three times before they get to the stage where they think this is going to work. It's a revolving door.
Every time they come through they engage a little bit longer."
The team at DAIS helps about 45 people, ranging from street sleepers and
ex-convicts to high-flying City executives.
As Theresa explains, drugs don't discriminate on the grounds of age, race or class and can quickly become anyone's 'best friend'.
Asif started taking heroin to cope with family issues.
"My mum was diagnosed with a serious illness and I was having relationship problems as well," he said.
"When you're using drugs you feel good and you want that feeling back, but after a while you realise it's not doing anything and it's not going to solve any problems.
"I sold drugs and I would be with people who were doing fraud or shoplifting. There's always someone you're hurting in order to get the money for drugs."
Even once you've gone clean, it's another thing staying off drugs, with temptation everywhere from TV to the high street.
"I know people who still can't walk down the tin foil aisle at Tesco without thinking about heroin, despite not using for 10 years," said Theresa.
"Codeine and heroin come from the same plant and taking paracetamol tablets (which often contain codeine) can actually trigger people to start using heroin again.
"There's one man who drops in every year just to see us, and we've had wedding invites, but usually we know we've done our job when we don't see people again."
The DAIS centre, at Red Lion Court, Alexandra Road, Hounslow, is open Monday to Friday, from 9am-5pm (11am-7pm Wednesdays). Call 020 8538 1700 for support.