[Impact of the COVID-19 pandemic on cannabis use in young adults and general population: a systematic review].

Objective: The first COVID-19 lockdown was a very restrictive situation that may have impacted on the prevalence and patterns of cannabis use. The aim of this systematic review was to assess the evidence on cannabis use and reasons for use in different countries during first lockdown in young adults and general population.

Methods: This study followed PRISMA guidelines, and the review protocol was registered in PROSPERO (registration CRD42022303181). The search was carried out in PubMed, Scopus, Web of Science y Embase databases. Inclusion criteria were: cross-sectional or cohort studies; population ≥16 years; exploring cannabis use during lockdown; and English or Spanish language.

Results: Thirty studies, conducted in European countries (n=17), North America (n=12) and rest of the world (n=1), were analysed. The overall prevalence of cannabis use was found to be largely unchanged, but regular users tended to maintain (between 39.5% and 96.8% of the sample) or increase cannabis use (between 2.9% and 51.6%). The main decreases were among occasional users. Some reasons for the increase were boredom, loneliness, stress, coping and depressive symptoms. In addition, young people were the heaviest users, and being younger, live without family, financial problems and a low educational level were significantly (p-value<0.05) associated with increased use.

Conclusions: Most regular users maintained or slightly increased their use, with young people being the main users. Concerning reasons for use like coping and depressive symptoms were found. Cannabis use needs to be addressed with strategies focused on the young population, considering occasional and regular use, as well as motivations.