Quitting smoking cannabis could improve memory after just one week of abstinence. To show this result, obtained on adolescents and young adults, is a research coordinated by Massachusetts General Hospital, which was published in The Journal of Clinical Psychiatry. The study investigated whether and how memory and attention varied after quitting smoking.

Previous evidence had revealed an association (although not shown causally) between the use of cannabis in adolescence and low neuro-cognitive functioning. Starting from this scientific proof and the high consumption of cannabis among adolescents (13% reported having used it in another questionnaire), this study was born with the aim of understanding if and after how long, stopping to smoke it, we can record an increase in some skills related to learning .

smoke cannabisTo do so, the researchers involved 88 participants between the ages of 16 and 25, in the area around Boston, who used cannabis at least once a week.

The volunteers were divided into two groups, one of which would stop smoking (at least) for 30 days, the duration of the monitoring, while the other would not have changed any habit. The researchers took into account and eliminated the influence of certain elements, such as pre-existing differences in learning, mood, ability to learn, motivation, and the frequency of cannabis use.

During the 30 days, they evaluated the memory and attention within the two samples of participants, who were also subjected to regular urine tests to verify abstinence or the level of exposure, measured by specific biomarkers.

According to the results, verbal learning, in particular the ability to learn and remember new information, was only strengthened among the volunteers who abstained from cannabis. The benefits for memory manifested themselves after a week of interruption of this habit and remained constant throughout the month of observation. On the contrary, abstinence had no effect on attention: both groups of boys showed an improvement in this ability, probably due to the effect of training during the tests.

 cannabis smoking“Our results provide two elements for convincing evidence,”explains Randi Schuster, first author of the paper. “The first is that teenagers learn best when they don’t use cannabis. The second – the good news of this study – is that some of the deficits associated with cannabis use are not permanent and the associated skills can be upgraded very quickly after you stop using it.”

The ability to learn and be able to metabolise new information, a key to success in the classroom, increases with a prolonged interruption of cannabis use, continues Schuster: “We can confidently say that these results strongly suggest that abstaining from cannabis helps young people to learn, while continuing to use it can interfere with the learning process”.

However, there is still much to understand, as the authors themselves point out. For example, it is important to study whether after a longer abstention it may also increase attention and if memory gains further advantages. These and other questions will be the focus of an extensive follow-up study, involving very young people aged 13 to 19 who use cannabis along with a group that has never consumed it, while another research will specifically study the effects abstention for 6 months. 

This result represents a first step in understanding how to stop using cannabis can produce benefits in academic and academic performance .