Individual and school-class correlates of youth cannabis use in Sweden: A multilevel study

Changes in co-use of alcohol and cannabis among Nordic adolescents in the 21st century: Results from the European School Survey Project on Alcohol and Other Drugs study

INTRODUCTION

In the 21st century, there has been a decline in alcohol use among adolescents in most Nordic countries, while trends of cannabis use have diverged. We explore how alcohol and cannabis use, respectively, and co-use of the two substances, have changed among Nordic adolescents. Three hypotheses are used to frame the study: (i) cannabis use has substituted alcohol use; (ii) there has been a parallel decline in both substances; and/or (iii) there has been a 'hardening' of users, implying that alcohol users increasingly use cannabis.

METHODS

Data from the European School Survey Project on Alcohol and Other Drugs, conducted among 15- to 16-year-olds in Denmark, Finland, Iceland, Norway and Sweden (N = 74,700, 49% boys), were used to explore trends of past-year alcohol and cannabis use in the period 2003-2019.

RESULTS

The proportion of adolescents reporting alcohol use decreased significantly in all Nordic countries except Denmark. The proportion of those using cannabis only was low (0.0%-0.7%) and stable in all countries. The total number of substance use occasions declined among all adolescents in all countries but Denmark. Among alcohol users, cannabis use became increasingly prevalent in all countries but Denmark.

DISCUSSION AND CONCLUSIONS

We found no support for the 'parallel decline hypothesis' in alcohol and cannabis use among Nordic adolescents. Partially in line with the 'substitution hypothesis', cannabis use accounted for an increasing proportion of all substance use occasions. Our results suggests that the co-use of alcohol and cannabis has become more common, thus also providing support to the 'hardening' hypothesis.

Prospective associations between adolescent risky substance use and school dropout and the role of externalising and internalising problems

Background: The aim of the present study was to assess to what extent risky substance use (RSU) acts as an important risk factor for school dropout from upper secondary school in a prospective study of Norwegian adolescents, and how externalising and internalising mental health problems influenced this association. Methods: We used data from a large population-based survey (the youth@hordaland-survey), which included adolescents aged 16-19 years. The predictor variables were self-reported RSU. The survey was linked with prospective data from the Norwegian Education Database, following the adolescents to 21-23 years of age. The outcome variable was registry-based school dropout within five years after starting upper secondary school. The analyses were adjusted for sex, age, socioeconomic status, and externalising and internalising problems. Results: After adjustment for sociodemographic variables, all indicators of RSU were prospectively associated with school dropout (adjusted odds ratios 1.26-2.25; all p values <.01). While internalising problems only slightly changed these estimates, the associations were substantially attenuated by externalising problems. Still, all measures of RSU, except frequent alcohol intoxication, remained positively associated with school dropout in the fully adjusted models. For the youngest students, all associations between RSU and school dropout were significant. Conclusions: Adolescent RSU is a strong predictor for school dropout, and externalising problems explained a considerable proportion of this effect. Prevention efforts to reduce student substance could improve academic outcomes among upper secondary school students, and such efforts may benefit from also targeting co-occurring externalising problems.

Is there a gender paradox in the association between conduct problems and cannabis use? A cohort-study among Swedish adolescents

INTRODUCTION

Conduct problems (CP) predict cannabis use prospectively but the research is mixed as to whether this association is stronger among girls. A stronger association among girls would suggest a 'gender paradox' as both CP and cannabis use is less common in this group. This study aimed to assess whether the longitudinal association between CP and cannabis use in Swedish adolescents is stronger among girls.

METHODS

Data from two waves of a nationally representative cohort study of Swedish adolescents born in 2001 were used. Baseline measurements were collected in 9th grade (at age 15-16) and follow-up measures at 11th grade (at age 17-18).

RESULTS

CP at baseline were significantly associated with cannabis use at follow-up adjusted for hyperactivity problems, emotional problems, socio-demographics, parental monitoring, school grades and truancy at baseline (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.06-1.24) but not when also adjusting for substance use at baseline. Boys were more likely to have used cannabis during the past year, even when controlling for prior substance use (OR 2.29, 95% CI 1.76-2.98). The association between CP and cannabis use was significantly weaker for boys (OR 0.83, 95% CI 0.72-0.95 in the fully adjusted model). The predicted probability of cannabis use was stable at 0.13 for boys across levels of CP, but ranged from 0.05 to 0.16 for girls.

DISCUSSION AND CONCLUSION

The longitudinal association between CP and cannabis use was stronger among girls. The findings are indicative of a 'gender paradox' in the association between CP and cannabis use.

Risk factors for substance use in Swedish adolescents: A study across substances and time points

Aim: The public health model for prevention of disease and disorder has been influential in informing interventions regarding substance use. While a number of risk factors within this model have been found to predict substance use, few studies have explored the associations across substances, at different time points and in the same individuals. The aim of this study was to test this model across legal and illegal substance use among adolescents, and to identify potential changes in associations over time. Methods: Data from two waves of a nationally representative cohort study among Swedish adolescents were used. Baseline data were collected in 2017 (9th grade) with a follow-up in 2019 (11th grade). Using modified Poisson regression analyses, we explored cross-sectional associations between factors from different domains and prevalence of cigarette use, binge-drinking and illegal drug use at both baseline and follow-up. Results: The results in part supported the public health model. Substance use was predicted by factors within the family, school and the individual/peer domain, but several associations were not statistically significant. The only consistent risk factors across substances and time points were lack of parental monitoring, truancy and minor criminal activities. Conclusion: Despite widely different prevalence rates across substances, some risk factors were consistently associated with adolescent substance use. Nonetheless, the findings challenge the assumption that risk factors are stable over adolescence. They suggest a need for flexible prevention interventions spanning across substances and legal boundaries of substances, but also over domains to reflect the heterogenous needs of adolescents.

Are the well-off youth in Sweden more likely to use cannabis?

INTRODUCTION AND AIMS

Results from previous research are inconsistent regarding the association between socioeconomic status (SES) and cannabis use among adolescents. Since there are risks associated with cannabis use, a social gradient in cannabis use may contribute to reproducing socioeconomic differences in life opportunities. The aim of this study was to assess the association between childhood SES and cannabis use among youth in Sweden.

DESIGN AND METHODS

We used repeated cross-sectional data from three waves (2014-2016) of the Swedish national school survey among 11th graders. The analysis encompassed 9497 individuals in 668 school classes. Childhood SES was measured through parents' highest education, as reported by the students. Cannabis use was measured in terms of lifetime use and frequency of use. Data were analysed using multi-level mixed-effects Poisson regression.

RESULTS

Adolescents with at least 1 parent with university/college education had 17% (incidence rate ratio 1.17, confidence interval 1.05, 1.30) higher risk of lifetime use of cannabis compared with those whose parents had no university/college education, adjusting for sex, SES of the school environment, academic orientation, truancy, risk assessment and parental permissiveness. Among life-time users of cannabis, risk for frequent cannabis use was 28% (incidence rate ratio 0.72, confidence interval 0.53, 0.97) lower for those with at least 1 parent with university or college education.

DISCUSSION AND CONCLUSIONS

Childhood SES, in terms of parental education, was associated with cannabis use among Swedish adolescents. Adolescents from families with lower SES were less likely to ever try cannabis, but at higher risk for frequent use.

Relationships between Problematic Cannabis Use and Risky Behaviors in Spanish Adolescents

This study examined the relations between problematic cannabis use, physical assault, and getting involved in a motor vehicle accident under the influence of cannabis in a sample of adolescents randomly selected from 25 public and semiprivate high schools in Alicante (Spain). Participants (n = 648) completed The Spanish National Standardized Survey about drug use in high school adolescents (ESTUDES, 2017), which includes the cannabis abuse screening test (CAST). Prevalence of cannabis use across the life-span and within the past 30 days was 37.5% and 17.4%, respectively. CAST scores were associated with an increased risk of driving under the effects of cannabis, riding shotgun, and physical assault, but not with an increased risk of having a motor vehicle accident. There were no differences between boys and girls in the association of problematic cannabis use with risky behaviors. This result highlights the importance of comprehensive prevention and education strategies for adolescents at high risk of cannabis use.

Factors associated with cannabis use change in youth: Evidence from the COMPASS study

INTRODUCTION

Harmful effects of cannabis use in youth scale with frequency. In the context of approaching legalization in Canada, understanding the distinctions between youth who change and who maintain their cannabis use is essential for designing interventions and policy. A substantial number of characteristics may play a role. This study assessed whether and how youth who change their cannabis use differ from those who do not.

METHODS

Cannabis use was reported by 8375 Canadian high school students participating in the COMPASS study. GEE multiple logistic regressions were then used to establish impact of 13 baseline demographic and behavioural exposure variables on the likelihood of membership in four frequency change groups at follow-up a year later: reduction, cessation, escalation, and maintenance.

RESULTS

Groups were found to differ in several ways. Cessation group members (19.4% of users) were less likely to binge drink (OR 0.82), vape (OR 0.82), or attend class without completing homework (OR 0.72) than maintainers. Students who reduced their use (14.6% of users) were more likely to binge drink (OR 1.36), smoke (OR 1.20), and skip class (OR 1.21). Those who escalated (29.5% of users) were more likely to be male (OR 1.35) and to vape (OR 1.22).

CONCLUSIONS

Students who change their cannabis use differ in several demographic and behavioural characteristics. The results raise further concerns about the impact of e-cigarettes and the role of poly-substance use in high-risk trajectories. Distinct classes of cannabis users, essential for policy and intervention development, can be identified in high school populations.