The war on drugs has been declared a failure by the British Medical Journal. Prohibition laws have failed to curb either supply or demand, reduce addiction, cut violence or reduce profits for organised crime, the journal argues.

It says the ban on the production, supply, possession and use of some drugs for non-medical purposes causes huge harm.

The paper’s editor in chief Dr Fiona Godlee, and features and debates editor Richard Hurley point to the fact drug use has grown substantially worldwide, with a quarter of a billion adults worldwide having potentially taken illegal drugs such as cannabis, cocaine or heroin in 2014.

In the UK, a quarter of 15-year-olds may have taken illegal preparations of unknown quality and potency.

They say some countries have already removed criminal penalties for personal drug possession.

For example, Portugal replaced criminal sanctions for drug use with civil penalties and health interventions 15 years ago, while the UK’s new Psychoactive Substances Act criminalises the supply but not the use of synthetic drugs.

Some US states such as California have legal cannabis markets and the Netherlands has tolerated regulated cannabis sales for decades.

The editors call for doctors to be at the centre of the debate on alternative policies to promote health and respect people’s dignity.

“Health should be at the centre of this debate, and so, therefore, should healthcare professionals,” they write. “Change is coming, and doctors should use their authority to lead calls for pragmatic reform informed by science and ethics.”

In the same issue, former Liberal Democrat leader Nick Clegg and Baroness Molly Meacher say the UK’s drug policy has been irrational for 55 years and argue this is the right time to establish a wider review of drug policy.

They urge the Government to reschedule cannabis for medical use and review policy on heroin assisted treatment, which they say has shown positive results in Switzerland, such as a decline in drug use and crime and improvements in health and rehabilitation.

The Parliamentarians also call for an end to criminal sanctions for the personal possession and use of all drugs.

“British politicians should seriously consider introducing a version of the Portuguese model in the UK, involving a significant transfer of resources from criminal justice to treatment services,” they write.

They say steps towards decriminalisation in the UK have already begun, with the Psychoactive Substances Act 2016, and argue changes to drug prohibition “could be good for the UK.”

Ruth Dreifuss, former President of Switzerland and chair of the Global Commission on Drug Policy, says the need for more effective and humane drug policies is more urgent now than ever.

She argues the idealised notion of a “society without drugs” is an unattainable fantasy and says reforms must prioritise issues of public health, social integration and security, while respecting human rights and judicial process.

Decriminalisation can and must go further, she adds. In an upcoming report, the Global Commission calls for governments to regulate all illicit drugs, which it says would curb a massive revenue for organised crime worth an estimated $320bn.