One in two students sleeps poorly, according to a Heyme/Opinion way study published in March 2022. A lack of sleep is far from inconsequential on the health of young people and their academic success. Through a new study, published in Psychiatry Research, researchers from Inserm, the University and the CHU of Bordeaux were particularly interested in the consequences on sleep of the consumption (regular and occasional) of cannabis by students.
This study was conducted with 14,787 student volunteers, members of the i-Share cohort. The scientists sent them online questionnaires to determine the frequency of their cannabis use and the quality of their sleep over the past three months. "Such a large sample allowed us to form subgroups and refine the results," said Julien Coelho, first author of the study. In the panel, 3,030 (20.5%) students reported monthly use, 645 (4.4%) weekly use and 219 (1.5%) daily use of cannabis. Hence the need for such a large sample. "The sample sizes of these studies were often limited and did not take into account important confounders suspected in the association, such as mental health disorders, economic status, or use of sleeping pills," the study adds. .
Through this self-report, the researchers found that cannabis use increased the risk of having disturbed sleep. Specifically, cannabis users were 45% more likely to experience insomnia than non-users. To reach this conclusion, the researchers took into account many factors such as economic situation, precariousness, alcohol and tobacco consumption, mental health. So many elements to refine the results and avoid any bias in the analysis. "Taking into account all these factors, we have reached a fairly high degree of certainty regarding the link between regular cannabis use and poor sleep", summarizes Julien Coelho.
These results report a difference between regular and acute cannabis use: "Estimates increased steadily with frequency of use, reaching a twice as high likelihood of insomnia in daily users compared to never/rarely users," details the study.
However, this study does not make it possible to establish causality between the two elements. "Causality cannot be asserted, it is complex to obtain because it would require the implementation of a clinical study and a case-by-case study in order to build a reliable analysis model", explains the researcher. However, these results are sufficient to identify the likely link between cannabis use and sleep. "All this must be taken into account, the notion of sleep and the prevention of cannabis consumption must no longer be dissociated in prevention messages. You have to talk about both at the same time. »
