Studies by Harvard Medical School and the University of Montreal have identified the extent of the damage cannabis inflicts upon young brains.
In both studies the drug was shown to be linked with poorer memory function, which could seriously damage young people’s academic ability.
Mental health and drug addiction specialists have long worried about effects like this.
Psychiatrist Dr Max Pemberton said: “Whether its schizophrenia, anxiety or depression, serious mental health problems as a result of cannabis use are well-established.”
The use of it, he said, also limits “an individual’s ability to engage with the emotional response of others”.
According to reports, around one million young people in the UK have used cannabis.
Despite warnings about the drug’s relationship with psychosis, seizures by police have fallen.
The study from Harvard Medical School particularly revealed that cannabis damages young people’s ability to retain information and therefore do well at school.
It looked at 88 people between the ages of 18 and 25 who used cannabis regularly. Out of that group, some were then asked to quit for 28 days.
Those who stopped using cannabis saw a dramatic improvement in their ability to retain information after just one week.
Dr Randi Schuster at Massachusetts General Hospital’s Centre for Addiction Medicine said: “We can strongly say regular users will learn better when they abstain, and continuing to use the drug is likely to negatively impact the learning process.”
Dr Pemberton argued that such research is often ‘routinely dismissed’ by the pro-cannabis lobby.
With so much pressure to legalise cannabis, Dr Schuster emphasised: “We really need to be vocal about telling kids that their brains are still vulnerable”.