Scotland’s war on drugs amounts to a war on the poor, according one of the country's leading authorities on substance abuse.

In a new paper, Dr Iain McPhee, from the University of the West of Scotland's Centre for Alcohol and Drugs Studies, calls the Misuse of Drugs Act 1971, “unjust, unfair and unworkable.” McPhee was Project Leader of the National Drugs Helpline and the National AIDS Helpline, and has worked as a drugs specialist with social work and Scottish police.

According to the academic, tough key performance indicators to be met by officers from Police Scotland means that it is those living in areas of multiple deprivation, and seen as “problem drug users”, who are targeted the most.

Separately, another drug policy expert, former Scottish Government adviser Mike McCarron, has said that if drugs were decriminalised savings could be made by Police Scotland and health and social work amounting to £1.5 billion.

Although, according to a recent survey, drug crime is the public’s top priority for Police Scotland, McPhee says it is the enforcement of prohibition that “exacerbates drugs related crime” and says the way to deal with problematic drug use is through tackling social deprivation.

The force’s targets also explain why, since 2003, the arrest rate for drug dealers in Scotland is twice as high as it is in England and Wales.

McPhee told the Sunday Herald: “The war on drugs, one must conclude, is a war on the poor, as they are most affected by the performance indicators used by medicine, criminal justice social work, particularly child protection, and the police, enforcement and security agencies.”

He continued: “Only a continual challenging of the moral framework on which drug policy rests can lead to reforms of our unjust, unfair and unworkable drug policies.”

The academic said that the government was aware of this, and pointed to a report by John Birt commissioned by the Blair government. Birt’s report pointing out the unfairness of the act was then suppressed.

“All the things that we attribute to drugs, like poor health, or poor housing or poverty, these are in many ways enduring structural factors caused by inequality and deprivation, and these people when they use drugs may go on to be problem drug users, but the key factor here...is there is no relationship between the activity of the police, the availability of drugs and the number of drug users. And no matter what you spend on the misuse of drugs it can never achieve its aims.”

In a survey of 31,000 people across Scotland conducted by the police to feed into their annual plan, 28 per cent of the public said they wanted the force’s top priority to be tackling drug crime, ahead of road safety, violence and anti-social behaviour.

McPhee believes this is what has led to those in poorer areas being targeted. "I think it would be reasonable to conclude that they must be targeting scarce resources, which may or may not be intelligence-led, about where they think most activity which infringes the Misuse of Drugs Act 1971 occurs," he said. "That would appear to be specific areas in Scotland that are also where there is most inequality and deprivation. I think it's no secret that by far the majority of people who are attending services for treatment and the majority of people who are incarcerated for infringements of the Misuse of Drugs Act invariably reside in areas characterised by deprivation, no matter what index is used."

A police source told the Sunday Herald that most drug arrests were in poorer areas because that was where the problem drug users and the gangs were.

“Nobody in the west end of Glasgow, or in the posh bits of Edinburgh or Aberdeen is bothered if their neighbour is doing a wee bit of coke. But see when you’ve got junkies breaking into folks houses and stealing bikes and stereos so they can get their next fit then of course we should be there. And by and large that’s happening in poorer areas where there’s higher dependency and you have the presence of gangs,” the source said.

There is seemingly little appetite to devolve drug laws to Scotland. Although the Scottish Government’s default position is to want all powers transferred to Westminster, in the White Paper for independence, there was only a passing mention made to independence allowing “decisions on drugs policy and drug classification to be taken together in a coherent way.”

Politicians will be keenly aware of Police Scotland’s survey results. There are few votes to be won from backing drug law reforms. Former Scottish Government adviser Mike McCarron, however, is hopeful that reform could be on the cards.

“I don't see the Westminster Government either now or in the foreseeable future adopting significant change of direction in drug policy, so if drug policy is not fully devolved then a very 'strong voice' of Scottish MPs will be needed at Westminster to increase harm prevention and service effectiveness within a significant change of policy direction.”

McCarron, who works with Transform Drug Policy Scotland, believes decriminalisation and taxation and regulation of drugs could see the costs to Scotland of drugs harm reduced by as much £1.5 billion.

“This might include, regarding the £600 million spent on police and prisons, potentially several hundreds of millions pounds saved or redeployed for other policing needs and further tens of millions raised in tax for investments.

“So we should scrutinise every detail of the the estimated £3.5 billion socio-economic costs for potential savings and tax gains, comparing prohibition with regulation. Savings and taxes could fund a greater number of services to meet Scotland's very high needs and also improve the quality of services.”

Scotland does have a problem with drugs. And it is worse here than it is in the rest of the UK. According to the UN's World Drugs Report, Scotland has a greater per-head use of heroin, ecstasy and cocaine than almost any other country in the world.

David Liddell Director of Scottish Drugs Forum said it’s difficult to quantify exactly how many drugs are in Scotland and how many people are using them.

“The nature of an illegal trade is that you would only ever have fairly crude estimates. However, from the available statistics, a troubling picture emerges.”

Liddell says that latest figures from the government show 6.2 per cent of adults reported using a drug in the last year including 0.5% who had taken new drugs or legal highs. A quarter of those who used drugs said they “felt dependent”.

“The estimated number of individuals with problem drug use in Scotland is 59,500 - 1.68 per cent of the population - 2.43 per cent of all males and 0.96% of all females resident in Scotland. In this context, problem drug use is defined very narrowly in terms of the use of heroin and benzodiazepines such as diazepam. Our fatal drugs overdose figures are very high – far higher than in England, for example - and amongst the highest in Europe which in part merely reflects the high levels of problem drug use, in particular heroin use.”