Legalising recreational cannabis use would hurt the weakest in society, and could mislead teenagers into thinking it is safe, medics say.
While cannabis – in a medicalised and regulated form – may be able to help some patients, activists are also calling for recreational usage of the Class B drug to be allowed.
But the Royal College of Psychiatrists, the Chief Executive of the NHS, and former substance misuse adviser to President Obama have raised their voices in opposition.
The intervention follows former Foreign Secretary William Hague saying Britain should consider introducing “a lawful, regulated market in cannabis for recreational use”.
Speaking at a health conference in London on Tuesday, NHS chief Simon Stevens urged the UK to learn from territories where cannabis laws have been weakened.
…factually miserable, logically futile and morally reprehensible
“In countries where marijuana has been decriminalised, often young people, teenagers, come to think of smoking marijuana as safe.
“Whereas let’s be clear, actually it isn’t”, he said.
Dr Kevin Sabet, who has advised three US Government administrations on drugs, noted that cannabis today is much stronger than in previous years.
And he warned: “Frankly, the weakest in society would be hurt, not Lord Hague and his friends.”
The Royal College of Psychiatrists also spoke out on the clear link between cannabis and psychosis, underlining widespread mental health concerns.
Janie Hamilton, whose son’s death was linked to cannabis-induced mental illness, said she felt “very cross” after hearing Lord Hague’s comments: “I am concerned that the dangers of cannabis are being forgotten in all this”.
Newspaper columnist Peter Hitchens described the former Conservative leader’s comments as “factually miserable, logically futile and morally reprehensible”.
As debate intensified in the UK, Canada paved the way for recreational cannabis to be legal in the coming months.
Its Senate backed Justin Trudeau’s legislation by 52 votes to 29. The country already allows marijuana for medical purposes.