Young people may be even more vulnerable to the health risks of cannabis than previously thought, new research suggests.
In a landmark trial of more than 100 adults and children in London, scientists found that teenagers who used the drug had much worse memory and concentration problems than adults who smoked cannabis.
This was seen regardless of the force or amount consumed.
Scientists warned this was a sign that it could be “significantly more dangerous” for teenagers and “disrupt” their development.
It comes as intriguing data yesterday suggested that Americans now ingest the drug more regularly than alcohol.
About 17.7 million people in the United States use the drug daily, compared to 14.7 million daily drinkers, according to results from the National Survey on Drug Use and Health.
This is the first time since records began in 1979 that marijuana has surpassed alcohol, a trend that experts say is a direct result of widespread legalization.
Dr Rachel Lees, author of the study and an expert in addiction and cannabis use disorders at the University of Bath, said: “We already knew from previous research that adolescents have higher rates of cannabis use disorder than adolescents. Adults”.
Cannabis use disorder, a recognized psychiatric disorder, occurs when people cannot stop using marijuana, even though it is causing social and health problems, such as affecting their work and relationships.
Dr Lees added: “Until now we did not know whether this was because younger people simply used more or more cannabis than adults. We now know this is not the case.”
Researchers questioned 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 it was for them to stop taking the medication, any problems they had with memory or concentration after using it, 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 marijuana that causes the high, used by the volunteers.
Participants then received a score from 0 to 32. On average, adolescents scored 3.7 points higher than adults.
Dr Lees added: “Throughout the 12 months of the study, adolescents (in the study) consistently scored higher than adults, indicating that they faced more difficulties with cannabis.
‘We found that 70 per cent of teenagers reported that they had failed to do what was normally expected of them due to cannabis use, while only 20 per cent of adults reported having experienced this.
‘We found that this effect was not due to adolescents using more cannabis than adults.
‘Furthermore, 80 percent of adolescents reported spending a significant amount of time starting, 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 perceive cannabis to be associated with a low level of risk of harm.
“We hope that these findings will increase awareness among young people about the potential risks of cannabis use, encouraging them to consider ways to mitigate these risks, such as stopping or reducing their use.”
Cannabis use disorder, a recognized psychiatric disorder, occurs when people cannot stop using marijuana even though it is causing social and health problems, such as affecting their work and relationships.
Experts speculate that teenagers are particularly vulnerable to cannabis use disorder because their brains are still developing.
The latest figures show that cannabis remains the most popular drug among 16-59 year olds in England and Wales.
Last year it was highest among 20- to 24-year-olds – almost one in six people in this group used it, official figures show.
Last year, 32 deaths in England and Wales and around 300 in the United States were attributable to marijuana.
Studies also show that those who use cannabis daily (and mostly smoke it) are 25 percent more likely than non-users to have a heart attack and 42 percent more likely to have a stroke.
A 2019 study by researchers at Kings College London also found that daily use of high-potency marijuana can increase the risk of psychosis five-fold.