Almost all cannabis seized by police is now high-potency ‘skunk’, a new study shows, prompting concern about the “significant hazard” to mental health.
The study’s senior author Dr Marta Di Forti said more public education on the harms of cannabis is needed, as that is a “powerful tool” in curbing usage.
The research revealed that 94 per cent of cannabis confiscated by police in five areas of England was skunk – compared to just over half in 2005.
There are currently calls to weaken the present law, which carries major penalties for possession of the Class B drug.
The latest study analysed almost a thousand police seizures of cannabis from London, Kent, Derbyshire, Merseyside and Sussex.
Comparing the same areas over an eleven year period showed an increase in skunk seizures from 51 per cent, to 85 per cent and then 94 per cent.
The average concentration of THC – the main psychoactive component of cannabis – was also shown to have increased.
Dr Di Forti, of King’s College London, said the university’s previous research had shown an increased risk of psychotic disorders for skunk users.
She added that the rise in “high-potency cannabis on the streets poses a significant hazard to users’ mental health”.
“More attention, effort and funding should be given to public education on the different types of street cannabis and their potential hazards.
“Public education is the most powerful tool to succeed in primary prevention, as the work done on tobacco use has proven”, she added.
Last year, a mother spoke out about the dangers of cannabis following the death of her son.
James Hamilton was diagnosed with testicular cancer in 2014 but doctors believe his cannabis-induced schizophrenia led him to refuse treatment.
His mother Janie said: “Anyone who doesn’t believe cannabis can lead to mental health issues needs to come and watch the anguish and what it has done to families like ours.”