Cannabis use settings matter: National-level prevalence rates, correlates, and consequences of solitary cannabis use among high school students in Norway

Introduction Use settings appear increasingly relevant in understanding underage cannabis use. This study explored heterogeneity of cannabis use settings among high school students, with a particular focus on solitary use; its national prevalence rates, correlates, and associations with a wide range of negative consequences. Methods The analytical sample was comprised of students who reported past-year cannabis use ( n = 973, 62.2% male) in two nationally representative, cross-sectional surveys of Norwegian high school students conducted in 2021 and 2025. Students also reported on their cannabis use settings, socio-demographic and individual characteristics, and experienced negative consequences. Results While almost all participants reported social use, 24.3% also reported using alone (“Solitary+”). The regression analyses indicated that these use settings were associated with different characteristics, providing unique user profiles. More importantly, the “Solitary+” use setting was associated with a significantly greater overall number of experienced negative consequences (5.41 vs. 2.89; t(df) = 2.52, 95% CI[1.81, 3.23]), as well as with greater odds of experiencing consequences from seven of the ten possible harm domains, including mental health (aOR = 1.6, 95% CI[1.52, 2.31]), apathy (aOR = 2.1, 95% CI[1.35, 3.14]), relationship- (aOR = 2.1, 95% CI[1.31, 3.38]), school (aOR = 1.8, 95% CI[1.29, 2.7247]), and law enforcement problems (aOR = 2.2, 95% CI[1.50, 3.25]) even after accounting for multiple risk factors including cannabis use frequency. Conclusions One in four high school students who used cannabis past year engaged in solitary use. This use setting was associated with unique risk factors as well as with both a greater number and greater variety of negative consequences.