A study carried out by researchers at McGill University in Montreal (Canada) and relayed by the media New Atlas, affirms that cannabis is one of the substances most consumed by adolescents around the world. However, this period of life corresponds to a decisive phase of brain development, a phase on which consumption could have a significant impact.
According to psychiatrist Massimiliano Orri, lead author of the study, “Young people under the age of 15 are in a critical period of brain growth, which may make them more vulnerable to the mental health effects of cannabis”. At this age, the emotional area of the brain is formed more quickly than that of reasoning, which continues to mature until the twenties.
The scientists followed 1,591 participants from birth to 23 years old. The data collected made it possible to establish three profiles: non-consumers (60%), late consumers (20%), and early and regular consumers (20%). The researchers adjusted their models by taking into account 32 factors that could influence the results, such as socioeconomic status, medical history or parental substance use.
Increased risks before age 15
Their conclusions? Young people who started before the age of 15 have a 51% increased risk of consulting for a mental disorder and a 57% increased risk of receiving treatment for depression or anxiety. In terms of physical health, these same young people have an 86% higher risk of seeking care, particularly for injuries or poisoning. In contrast, no correlation was observed with respiratory illnesses or suicidal behavior.
For young users who started after 15 years, the researchers did not observe a significant increase in the use of psychiatric care, even if a slight increase in consultations linked to physical injuries remains. Non-consumers remain, unsurprisingly, the least affected by health problems.
The authors of the study, however, qualify these results: certain unmeasured personality traits or genetic factors could influence both consumption and health. Study dropouts, more common among men and low-income participants, can also bias the data. Furthermore, the study was carried out before the legalization of cannabis in Canada in 2018, at a time when products were less concentrated in THC.
Despite these limitations, researchers call for strengthening prevention among younger people. If the legalization of cannabis may have made its use commonplace, this study reminds us that early consumption is not without risk. During adolescence, the brain remains under construction: any chemical disturbance can leave its mark.
