Calderdale Substance Misuse Service: Addict recovery 'slow'
Addicts in part of West Yorkshire spend years in treatment schemes with limited chance of recovery, according to a report seen by the BBC.
Researchers have looked at the outcomes for heroin and crack cocaine users at Calderdale Substance Misuse Service.
It said every year they spent on a treatment programme raised the odds of recovery by 7% and it would take 10 years before the odds were doubled.
NHS Calderdale said it had a "good track record" of treating addicts.
The research team, from the University of Huddersfield, concluded that while the Halifax-based service was good at keeping people in treatment, the gains in recovery were "very slow".
It also found that addicts who use crack cocaine were less likely to recover than others and people using the service were not engaging in education.
Deirdre Boyd, from the Addiction Recovery Foundation, said: "It's at one and the same time both horrifying and not surprising.
"They are very bad results, people not getting off drugs, but at the same time Calderdale isn't an exception, it's symbolic of what's going on in the rest of the country."
A spokesman for NHS Calderdale said: "The report published by University of Huddersfield is still in draft form and has not been signed off by us as commissioners of the report.
"The study began in 2009 and therefore it reports on the services available at that time rather than the current services. The draft findings show a picture of recovery that is similar across the country and reflects the way in which substance misuse services have traditionally been provided.
"Calderdale Substance Misuse Service provides treatment and recovery services for local people in partnership with other third sector providers. It has a good track record of successfully identifying and providing effective treatment for people who have drug and alcohol problems."