Young people are even more vulnerable to the harms of cannabis than previously thought, British research shows, as the drug eclipses alcohol consumption for the first time in the US

Young people may be even more vulnerable to the health risks of cannabis than previously thought, according to research today.

In a groundbreaking study of more than a hundred adults and children in London, scientists found that teenagers who used the drug reported much worse problems with memory and concentration than adults who smoked cannabis.

This was seen regardless of strength or amount consumed.

Scientists warned this was a sign that it could be ‘significantly more dangerous’ for adolescents and could ‘disrupt’ their development.

It comes as intriguing data yesterday suggested that Americans are now taking the drug more regularly than alcohol.

About 17.7 million people in the U.S. use the drug daily, compared to 14.7 million daily drinkers, according to findings from the National Survey on Drug Use and Health.

This marks the first time since records began in 1979 that marijuana has overtaken alcohol — a trend experts say is a direct result of widespread legalization.

Dr. Rachel Lees, study author and expert in addiction and cannabis use disorders at the University of Bath, said: ‘We knew from previous research that adolescents are more likely to have cannabis use disorders than adults.’

Cannabis use disorder – a recognized psychiatric disorder – occurs when people cannot stop using marijuana, even though it is causing health and social problems, such as their work and relationships.

Dr. Lees added: ‘Until now we didn’t know if this was because younger people were simply using more or stronger cannabis than adults. We now know that this is not the case.’

The researchers surveyed 70 adults, ages 26 to 29, and 76 adolescents, ages 16 to 17, every three months for a year about their symptoms after using cannabis.

This included how difficult they found it to stop using the drug, any problems they had with memory or concentration after use and whether it had interfered with their daily obligations.

They also tracked the frequency of each symptom and took into account the amount of THC – the active ingredient in cannabis that produces the high – used by volunteers.

Participants were then given a score from 0 to 32. Teenagers scored on average 3.7 points higher than adults.

Dr. Lees added: ‘Over the 12 months of the study, adolescents (in the study) consistently scored higher than adults, indicating they had more difficulty with cannabis.

‘We found that 70 per cent of teenagers reported not having done what was normally expected of them by using cannabis, while only 20 per cent of adults reported experiencing this.

‘We found that this effect was not due to the adolescents using more cannabis than the adults.

‘Also, 80 percent of adolescents report spending a lot of time obtaining, using or recovering from cannabis use, compared to 50 percent of adults.

‘This is concerning as this group may not be aware of the symptoms of cannabis use disorder and may be led to believe that cannabis is associated with a low risk of harm.

‘We hope these findings will raise awareness among young people about the potential risks of cannabis use, and encourage them to think about ways they can reduce these risks, such as stopping or reducing use.’

Experts speculate that adolescents are particularly vulnerable to cannabis use disorders because their brains are still developing.

The latest figures show that cannabis remains the most popular drug among 16 to 59 year olds in England and Wales.

It was highest among 20 to 24-year-olds last year, with almost one in six people in this group using it, official figures show.

Last year, 32 deaths in England and Wales and around 300 in the US were linked to cannabis.

Research also shows that those who use cannabis daily – and especially smoke it – are 25 percent more likely to have a heart attack than non-users, and 42 percent more likely to have a stroke.

A 2019 study from researchers at Kings College London also found that daily use of high-potency cannabis can increase the risk of psychosis fivefold.