More than a million people in the UK are estimated to be addicted to prescription drugs known as benzodiazepines. But with withdrawal symptoms similar to those experienced by heroin addicts, those who find themselves addicted are calling for more help and a change in the way the drugs are prescribed.
"Being addicted is hellish. When I get up in the morning I need to take my meds so I can function, so I can be a whole person."
Josh, 50, was first prescribed a benzodiazepine, a tranquiliser, as a hyperactive eight-year-old and has been addicted ever since.
He is among the 1.5m people across the UK the All Party Parliamentary Group on Involuntary Tranquilliser Addiction (APPGITA) estimates are addicted to this group of drugs, which are also known as 'benzos'.
Benzos include diazepam and temazepam, and are commonly prescribed by GPs for a range of conditions such as anxiety and insomnia.
They act by enhancing the effect of a brain chemical transmitter called gamma-aminobutyric acid (GABA), which depresses or calms the central nervous system, slowing down mental activity to cause relaxation and sedation.
But some experts say that coming off benzos can be harder than stopping taking heroin.
"I estimate about 20-30% (of people) who are on benzos have problems coming off, and about a third have very distressing symptoms," says Professor Malcolm Lader of the Institute of Psychiatry.
"The anxiety comes back or sleeplessness comes back and they feel physically ill.
"Then they get bizarre symptoms.
"Essentially, the brain wakes up and then over-wakes, sounds appear louder, lights appear brighter, and they feel unsteady. It's then they're in a bad withdrawal state."
Josh has tried to stop taking the drug many times.
"You sweat, hot and cold sweats, you get diarrhoea and a sense of going mad," he says.
"It's horrendous. I've never found a cut-off point where I've said, 'It's better', because the symptoms persist.
"The longest time I've been off benzos was eight weeks.
"I know that sounds like a short time but I can assure you that eight weeks is a really long time to be experiencing those symptoms every day, and they don't get better.
"And without the support, in the end my body said, enough, I must take a tablet, I can bear this no longer."
Lack of services
The support Josh longs for is the kind that is already provided in drug addiction centres for users of heroin and cocaine.
"We didn't wake up and say, 'Lets get addicted'," says Josh.
"We got addicted involuntarily and those who have been brave enough to try and address our addiction and have failed, we're still as stuck in that cycle.
"Please help us. Give us some support. Don't abandon us now."
Tranx, a support group based in Oldham, Manchester, run by ex and partially-withdrawn addicts, is unique in bringing together two charities - one with NHS funding - to provide two nurses.
"In Oldham I've seen six suicides and 50 attempted suicides," says Barry Haslam, who runs the support group, and is himself a former benzo addict.
"One weekend there were people wanting to commit suicide on the Friday, Saturday and Sunday night. It's just so sad there's nothing out there.
"We're volunteers in all this. Where are the services to help these people?" he says.
But as Professor Malcolm Lader, of the Institute of Psychiatry says: "The facilities are simply not available."
He adds: "The great scandal is addicts are referred to illegal drug addiction centres, and they're sat next to an illegal drug user who's been injecting heroin, and of course a housewife who's been prescribed by her doctor will be very upset by this."
Anne Milton, England's public health minister, admitted to BBC Radio 4's Face the Facts that there there had been some denial of the problem, but added the Department of Health is trying to "get a grip" of it and provide help for those who want to withdraw.
"I'm taking this very seriously, it's an issue that's fallen through the cracks, it's a silent addiction. Not many people know about it.
"We want to make sure training and awareness is raised so GPs can prescribe well, and then we've got to make sure we've got the right services in place to help them enjoy lives as they should be able to."
Rise in prescriptions
The potential dangers of withdrawing from benzos have long been known.
The recommended maximum time benzos should be prescribed is four weeks, according to government guidance.
Yet in England, the number of prescriptions issued last year rose by 8% to almost 11.5 million.
A recent report by the National Addiction Centre, Kings College London, which looked at prescribing in England for the 19 years up to 2009, found over a third of prescriptions during this period were for more than eight weeks.
But the Royal College of General Practitioners defends the prescription of these drugs, saying the way GPs have been dealing with patients in recent years is a "prescribing success" story.
Dr Clare Gerada, the organisation's chair, says that benzodiazepines are effective drugs, adding that most patients can withdraw easily, but that for others, staying on the drug may be a better option.
"Patients that I see, on the whole, do not have problems coming off. Some patients may be on them for life.
"It's not a good thing, but if you balance the risks and benefits then sometimes the benefits of staying on them far outweigh the risks."