Early cannabis use may affect school performance

«Let's roll a spliff!» is a phrase many teenagers hear on a daily basis. Today, France is the European country with the highest consumption of cannabis, ahead of Italy, Estonia and Poland. And this consumption starts earlier and earlier, with French teenagers also being the continent's biggest consumers.

Young boys' consumption at age 15 in Europe and North America

Girls' consumption at age 15 in Europe and North America

These two maps from the’World Health Organization (WHO) compare the percentage of girls and boys who have already smoked a joint by the age of 15 in Europe and North America. In France, at least 29% of boys and 26% of girls have already smoked a joint, while the European average is around 15%. The countries most affected for boys are France, Switzerland, Poland and Italy, while for girls, we find once again our beloved country, followed by Canada and Bulgaria.

A hindrance to school results?

A new study published in International Journal of Epidemiology shows the causal link between the initiation of early cannabis use, i.e. before the age of 17, and subsequent educational outcomes. Cannabis use in adolescence predicts the level of education the teenager will achieve.

The study compares young consumers, taking into account the socio-demographic characteristics of adolescents and their parents. However, it does not take into account certain difficulties that adolescents may encounter, such as psychological disorders.

The study tracked French teenagers, both users and non-users. It found that adolescents who smoked cannabis at an early age had more likely than non-smokers not to go beyond the baccalaureate. Adolescents who started smoking cannabis after the age of 17 have, according to this study, a level of education comparable to that of non-smokers. Finally, the study shows that the link between early cannabis use and educational attainment is more pronounced in girls than in boys.

The results also show a low level of academic achievement among teenagers who start smoking joints at an early age. They need the attention of addiction specialists to limit the long-term risks. As a reminder, the Observatoire français des Drogues et des Toxicomanie (OFDT) estimates that young French people's first experience of cannabis is as follows between the ages of 11 and 15.

Risks depend on the dose and quantity of cannabis consumed

The teenage brain is very sensitive because THC, the psychoactive molecule in cannabis, will disrupt development of brain areas, This is particularly the case with lesions that can disrupt concentration, lower motivation and cause memory loss, all of which can lead to failure at school.

The dose of cannabis consumed is not mentioned in the study. Yet we know that the number of bangers smoked will influence the results. According to another study in the scientific journal Hippocampus carried out in 2015, heavy cannabis users show abnormalities in the hippocampus, an area of the brain located in the temporal lobe, which is one of the memory centers. People who smoke the most cannabis then have more long-term memory difficulties.

Mehdi Bautier