Unrealistic targets to get more drug addicts into treatment are causing the quality of services to plummet, psychiatrists are warning.

Their comments come as the government plans to deny benefits to people with drug dependencies unless they undergo treatment.

Colin Drummond of King's College London's institute of psychiatry said the problem had been growing over the past two to three years but had intensified in the past year.

He said: "There's increasing pressure from the centre to increase the number of people in treatment.

"In some cases this is unrealistic. I don't disagree with the objective to get more people into treatment but there's a balance to be struck between quantity and quality."

Meeting targets

A public service agreement target to double the number of problem drug users in treatment programmes from 1998-2008 was met two years early, but the National Treatment Agency for Substance Misuse has been encouraging commissioners to use local "stretch" targets to push even further ahead.

Professor Drummond said commissioners had been retendering services to increase capacity, replacing programmes staffed by addiction psychiatrists with services run by GPs and drug workers.

This meant specialist knowledge, vital in complex cases such as childcare proceedings, was being lost. GPs sometimes lacked skills in dealing with drug misusers with mental health problems.

Failing to cope

Continuity of care was lost when services transferred from the NHS then had to be taken back by mental health trusts when the new providers could not cope. This was particularly problematic because many patients needed long term treatment, Professor Drummond said.

Royal College of Psychiatrists addictions faculty chair Michael Farrell said access was better but "issues of quality control" remained.

National Treatment Agency quality director Annette Dale-Perera said there were 453 addiction psychiatrists in 2008, up from 74 in 2004.

"Some commissioners' knowledge about what addiction psychiatrists can do needs improving," she said. New guidance on drug treatments will be published in the autumn.