The UK has the highest level of problem drug use and the second highest level of drug-related deaths in Europe, according to a report.
Despite successive governments’ attempts to control the demand for and supply of illegal drugs, drug policy appears to have had "minimal" impact on the overall level of use in the UK, according to its authors.
However, they do credit drug policy with succeeding in addressing certain illnesses and aspects of criminality associated with problematic drug use.
The report, by experts Professor Peter Reuter of Maryland University in the US and Alex Stevens of the European Institute of Social Services at Kent University, has been commissioned for Wednesday’s launch of the independent UK Drug Policy Commission.
Chaired by Dame Ruth Runciman and funded by the charitable Esmee Fairbairn Foundation, the commission aims to "improve political, media and public understanding of drug policy issues and the options for achieving a rational and effective response to the problems caused by the supply of and demand for illegal drugs".
It brings together 12 experts drawn from the drug treatment and medical research fields along with senior figures from policing, public policy and the media.
Speaking ahead of Wednesday’s launch, Dame Ruth said: "At the outset of our three-year work programme, UKDPC is agreed upon one thing – we currently do not know enough about which elements of drug policy work, why they work and where they work well."
Also serving on the commission are the chief executive of the Medical Research Council Professor Colin Blakemore; former West Mercia Chief Constable David Blakey; the president of the Royal Society of Medicine, Baroness Finlay of Llandaff; comment editor at The Times Daniel Finkelstein; chairman of the Mental Health Act Commission Lord Patel; chief executive of Shelter Adam Sampson; and the director of the National Addiction Centre Professor John Strang.
Marjorie Wallace, chief executive of the mental health charity Sane, said: "Cannabis, particularly skunk, is finally being recognised as having potentially devastating effects on the developing brains of some young people. Figures show that 50% of 16-34 year-olds admit to using the drug, which means that if only a small proportion develop psychotic symptoms, there could still be a worrying increase in the number who may have to endure lifelong mental illness such as schizophrenia.
"We hope this new commission will be able to provide guidance which takes account of all the evidence so that in future those potentially at risk and their families could be saved the anguish and heartbreak we hear about every day."