IT GAINED notoriety in the 1960s as mother's little helper'' ... but now Valium is Scotland's hidden drugs scourge, affecting thousands from all sectors of society.

An investigation by the Sunday Herald has revealed a shocking picture of the scale of use of powerful tranquillisers known as benzodiazepines. Those abusing the drug range from heroin addicts to middle-class cocaine users, while others have unwittingly become hooked for decades after being prescribed the medication by doctors.

Illicit supplies of the drug are also flooding in to Scotland from abroad, and it can be bought on the streets for as little as 50p, as well as being easily obtained over the internet.

Valium, which is now prescribed under its generic name diazepam, is one benzodiazepine. This drug group is used to help overcome anxiety and sleep deprivation, but can lead to addiction and horrific withdrawal symptoms.

The findings uncovered by the Sunday Herald include: l Concerns over a surge in demand for benzodiazepines from cocaine users keen to wind down after weekends of excess.

l An estimated 38,000 addicts of substances such as heroin using benzodiazepines in Scotland, increasing the risk of death. Diazepam was involved in nearly a fifth of drug-related deaths in 2006 - more than cocaine or ecstasy.

l Prescriptions of diazepam increasing by 60% in the past decade, from just in excess of half a million per year in 1996 to more than 800,000 in 2007.

l People addicted to diazepam for up to four decades after being prescribed the pills, but struggling to find the help they need to come off the drug.

l Seizures of illicit benzodiazepines reaching record levels in 2006, with 5kg recovered by police.

Dr Des Spence, a GP based in Maryhill, Glasgow, has reduced the prescribing of diazepam in his surgery by up to 80% in the past two months amid concerns drug addicts were selling the pills on.

He called for a debate over the prescribing of the drug, arguing a voluntary ban by GPs should be considered in problem areas such as Glasgow. There should be an emphasis on offering alternative counselling treatments instead of pills for suitable patients, Spence said.

According to Professor Neil McKeganey, director of Glasgow University's Centre for Drug Misuse Research, an estimated 38,000 drug addicts are using benzodiazepines in Scotland. They often reported symptoms of anxiety and difficulty sleeping to obtain it from doctors.

Once you start withdrawing it, the individual is going to start to experience conditions such as anxiety and difficulty sleeping - conditions for which the drug was prescribed in the first place," he said.

Detective Sergeant Kenny Simpson, of Strathclyde Police drugs squad, said the majority of diazepam on the illicit market was not diverted" from GP prescriptions, but smuggled into the country.

The issue is availability and big problems with it coming in from India and Pakistan where there are well-established transport routes and society connections with the UK,'' he said.

One recent problem, he added, was the popularity of cocaine, resulting in a greater demand for diazepam. Cocaine users very often find they need to get themselves back into a state where they can get back to work or calm down from their chemical intake over the weekend,'' he said.

Simpson described the use of diazepam as extensive'', but added it was a silent problem'' because many people bought the drug on the illicit market and never presented for treatment.

David Liddell, director of the Scottish Drugs Forum, echoed that view. The scale of it, I think, we will never really know because so much of it is hidden and will remain so,'' he said.

Others across the UK have struggled for years to come off benzodiazepines after being legally prescribed them.

Campaigner Barry Haslam helps run a support group in Oldham, Lancashire for those addicted to benzodiazepine drugs. The guidelines say these drugs should only be used for two to four weeks, but people have been on this stuff for 20, 30, 40 years,'' he said. You think of any other parts of addiction - heroin or alcohol - there is something there to help people, but there isn't for legal drug addiction.

"Yet it can be far harder to come off benzodiazepines than it is heroin."

Prescriptions for diazepam have drastically reduced since the introduction of Valium in the 1960s, when doctors were accused of handing the drug out like "sweeties". Dr Dean Marshall, chairman of the BMA's Scottish General Practitioners Committee, said the vast majority of GPs were now "very aware" of problems associated with the drugs.

"I would be very surprised if a doctor wrote a prescription without thinking about the risk of the patient becoming addicted or if the patient was likely to pass it on to someone else," he said.

But there are still concerns surrounding overprescribing by medics. One user of benzodiazepines told the Sunday Herald he had recently been given repeat prescriptions for eight months without having to see a doctor. "The doctors do say they are addictive, but I think GPs are overworked at the moment and people fall through the net," he said.

A spokeswoman for the Department of Health said it had focused on trying to prevent addiction occurring in the first place by warning prescribers of the dangers of involuntary addiction.

A spokeswoman for the Scottish government said guidelines were in place for the treatment of patients with dependence on benzodiazepine, which was available through drug treatment services.