Ready, willing, and able: the role of cannabis use opportunities in understanding adolescent cannabis use

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.

The great decline in adolescent risk behaviours: Unitary trend, separate trends, or cascade?

In many high-income countries, the proportion of adolescents who smoke, drink, or engage in other risk behaviours has declined markedly over the past 25 years. We illustrate this behavioural shift by collating and presenting previously published data (1990-2019) on smoking, alcohol use, cannabis use, early sexual initiation and juvenile crime in Australia, England, the Netherlands, New Zealand, and the USA, also providing European averages where comparable data are available. Then we explore empirical evidence for and against hypothesised causes of these declines. Specifically, we explore whether the declines across risk behaviours can be considered 1) a 'unitary trend' caused by common underlying drivers; 2) separate trends with behaviour-specific causes; or 3) the result of a 'cascade' effect, with declines in one risk behaviour causing declines in others. We find the unitary trend hypothesis has theoretical and empirical support, and there is international evidence that decreasing unstructured face-to-face time with friends is a common underlying driver. Additionally, evidence suggests that behaviour-specific factors have played a role in the decline of tobacco smoking (e.g. decreasing adolescent approval of smoking, increasing strength of tobacco control policies) and drinking (e.g. more restrictive parental rules and attitudes toward adolescent drinking, decreasing ease of access to alcohol). Finally, declining tobacco and alcohol use may have suppressed adolescent cannabis use (and perhaps other risk behaviours), but evidence for such a cascade is equivocal. We conclude that the causal factors behind the great decline in adolescent risk behaviours are multiple. While broad contextual changes appear to have reduced the opportunities for risk behaviours in general, behaviour-specific factors have also played an important role in smoking and drinking declines, and 'knock-on' effect from these behavioural domains to others are possible. Many hypothesised explanations remain to be tested empirically.

The Relations between Youth Cannabis Use, School Cannabis Use-Related Disciplinary Approaches and Student Perceptions of School Support

Background: In the school year immediately following cannabis legalization in Canada, this paper investigated youth perceptions of school support for the prevention and cessation of substance use. Scant research has examined student perceptions in relation to school disciplinary approaches. This study was the first to classify school discipline approach styles using school-level measures.Objective: The objective of this study was to examine whether different school cannabis use-related disciplinary approaches are associated with student cannabis use and perceptions of school supportiveness for the prevention and cessation of substance use.Results: School- and student-level survey data from Year 7 (the 2018/2019 school year) of the COMPASS study were used, including 68,037 grade 9-12 (Secondary I-V in Quebec) students attending 131 Canadian secondary schools. Schools were classified as using different cannabis use-related disciplinary styles based on school-administrator reported approaches to student first-offense violations of school cannabis policies. We identified that although none of the cannabis use-related disciplinary approach styles examined were associated with cannabis use, they were associated with student perceptions. Students attending schools classified as using a Permissive/Supportive approach had a higher likelihood of perceiving their school as supportive for substance use prevention/cessation than their peers at Authoritarian schools. Students who perceived their school as supportive for substance use prevention/cessation were less likely to report current cannabis use than their peers who perceived their school as unsupportive.Conclusions: Unlike previous studies using school classification styles that are based on student perceptions, results do not support direct associations between school cannabis use-related disciplinary styles and student cannabis use. Future prospective research should examine whether supportive disciplinary approaches (e.g., counseling referrals, educational programs) promote student perceptions of school supportiveness, and in turn, deter student substance use.

U.S. Trends in Adolescent Substance Use and Conduct Problems and Their Relation to Trends in Unstructured In-Person Socializing With Peers

PURPOSE

This study examined whether national trends in unstructured in-person socializing with peers (i.e., socializing without goals or supervision) among adolescents could help explain recent declines in adolescent risk behaviors (e.g., substance use, fighting, theft).

METHODS

The sample contained of 44,842 U.S. 12th-grade students (aged 17-18 years) from the Monitoring the Future survey (years 1999-2017). Analyses examined (1) prevalence trends, (2) latent factor structure of risk behaviors and unstructured in-person socializing, and (3) whether trends in the unstructured in-person socializing factor accounted for the relationship between time (i.e., survey year) and the risk behavior factor.

RESULTS

Adolescent risk behaviors and unstructured in-person socializing declined by approximately 30% in the U.S., and both formed coherent latent factors. After adjusting for sociodemographics, declines in unstructured in-person socializing accounted for approximately 86% of declines in risk behaviors.

CONCLUSIONS

The prevalence of risk behaviors and unstructured in-person socializing behaviors declined among U.S. 12th graders from 1999 to 2017. It is unknown whether such effects are directly causal and/or influenced by unmeasured variables. However, the results provide evidence that national declines in unstructured in-person socializing are a likely component of the explanation for national declines in adolescent risk behaviors.

Smoke in the air - Associations between experimentation with cannabis and the use of tobacco and nicotine products among 15-16-year-old school students

BACKGROUND

Cannabis is the most popular illicit drug among adolescents in developed countries, including Finland. The aim of this study was to estimate 1) how cannabis experimentation among Finnish adolescents changed between 2003 and 2019, and 2) whether the associations between cannabis experiments and factors related to it, especially the use of tobacco and nicotine products, changed during the same time period.

METHODS

The analyses are based on the European School Survey Project on Alcohol and Other Drugs data, collected from Finnish adolescents aged 15 to 16 in 2003, 2007, 2011, 2015, and 2019 (N = 20,630).

RESULTS

Experimentation with cannabis among Finnish adolescents has increased since the beginning of our follow-up. At the same time, alcohol use and smoking have decreased markedly, and attitudes toward cannabis use have become more relaxed. The association between smoking and cannabis experimentation has become weaker over time. However, the use of tobacco and nicotine products, especially polytobacco, is still a strong risk factor for experimentation with cannabis. The higher the number of tobacco or nicotine products used, the higher the probability for cannabis experimentation.

CONCLUSIONS

Experimentation with cannabis has previously been concentrated predominantly on adolescents who smoke, but recently non-smokers are increasingly trying cannabis. It is possible that alternative ways of using cannabis may have increased its use. Despite the strict cannabis policy in Finland, its use has increased, which may be an indication that youth cultures and images of different substances play a significant role in adolescents experimenting with cannabis.

Control of Recreational Cannabis in a New Zealand University Sample: Perceptions of Informal and Formal Controls

An increasing number of countries have, or are moving towards, reforming cannabis policies. New Zealand is also moving in this direction and the government will hold a referendum on the legalization of recreational cannabis in September 2020. To inform imminent public and political discussions it is important to understand how current cannabis use is controlled. Research suggests that cannabis law has been ineffective in NZ. Internationally, informal controls, rather than the law, have been found to shape cannabis use by creating a threshold for normalization, but the attitudes shaping this threshold are unknown. This study aimed to examine drug acceptability attitudes, specifically students' attitudes towards the illegal use of cannabis and their attitudes towards peers who abstain, sometimes use, or are heavy users of cannabis, to identify the factors that control cannabis use. Using a mixed methods approach, university students recruited their peers (N = 535) to complete a pen and paper survey investigating perceptions towards 3 cannabis user prototypes (abstainers, moderate users, heavy users), concern for legality of cannabis use, and the integration of cannabis into the student culture (perceptions of peers' use, ease of acquisition, and availability). Perceptions of peers' lifetime and regular use were 82% and 38.5%, respectively. Participants rated cannabis as easy to acquire and likely to be available at a typical student social occasion. The majority stated that the law does not deter use (92.7%); participants perceived the law to be soft and that they are unlikely to get caught. Participants' descriptions of the 3 cannabis user prototypes revealed a threshold for normalization. For instance, abstaining was perceived to be associated with positive attributes (such as being studious), linked to being less sociable, and linked to being less likely to be judged. Moderate use of cannabis was perceived to be normal and sociable. Heavy use was perceived to be associated with having negative attributes, such as being addicted, unhealthy, and an underachiever, and negative drug labels. Our findings revealed that cannabis use is not controlled by the law, but by informal thresholds of control. Moderate cannabis use is accepted whereas heavy cannabis use is not. We extended research by identifying the attitudes shaping these thresholds, in particular that negative outcomes associated with heavy use deters the normalization of this behavior. We argue that policy must be informed by, and build on, these informal controls. The negative perceptions associated with heavy use also raise concerns regarding the well-being of heavy users, and coupled with the ineffectiveness of cannabis law, lend support towards a health model for regulating cannabis. Furthermore, insights into the negative perceptions associated with heavy use could inform health interventions on the types of concerns that will resonate with users.

Perceived Ease of Access and Age Attenuate the Association Between Marijuana Ad Exposure and Marijuana Use in Adolescents

This study theorizes and tests moderators (perceived availability of marijuana and age-group) of the association between adolescents' frequency of marijuana ad exposure and past-year marijuana use. To test this model, I analyzed national survey data from 9,024 American adolescents with hierarchical regression techniques. Results showed that being a male (95% confidence interval [CI] for unstandardized regression coefficient [0.06, 0.16]) and peer pressure (95% CI [0.04, 0.14]) were positively associated with past-year marijuana use, and father education (95% CI [-0.11, -0.06]) was negatively associated with it. Perceived ease of access (95% CI [0.18, 0.22]), ad exposure (95% CI [0.03, 0.14]), and age (95% CI [0.16, 0.27]) were positively associated with past-year marijuana use. Importantly, the associations of perceived ease of access and age with past-year marijuana use were significantly larger than that of ad exposure. Age (95% CI [0.00, 0.15]) and perceived ease of access (95% CI [0.01, 0.07]) independently strengthened the ad exposure to use association. There was a significant three-way interaction (95% CI [0.01, 0.12]) showing that age increases the positive influence of perceived ease of access on the marijuana ad exposure to past-year marijuana use association. An exploratory analysis further revealed that male adolescents are more strongly influenced by perceived ease of access compared to females. Based on the findings, I suggest that approaches for reducing perceived marijuana availability and for implementing age-specific interventions are promising avenues for prevention programs aimed at decreasing marijuana use in adolescents.

Monitoring young lifestyles (MyLife) - a prospective longitudinal quantitative and qualitative study of youth development and substance use in Norway

PURPOSE

The Monitoring Young Lifestyles (MyLife) project was initiated as an integrated quantitative and qualitative prospective investigation of correlates, causes, and consequences of adolescent substance use and other addictive behaviours in Norway.

PARTICIPANTS

The MyLife cohort was recruited from middle schools in Norway, which were selected from low, medium and high standard of living areas in both rural and urban regions of the country. A total of 3512 eighth, ninth and tenth graders (55% girls) from 33 schools were enrolled in the quantitative project arm (QT), while a total of 120 eighth graders (52% girls) from six schools were enrolled in the qualitative project arm (QL).

FINDINGS TO DATE

QT baseline was conducted in the fall of 2017, when 2975 adolescents completed an online questionnaire at school during a regular class time. A total of 2857 adolescents participated in the first QT follow-up 1 year later. QL baseline was conducted across the fall semesters of 2014 (one class) and 2015 (five classes), when a total of 118 eighth graders completed face-to-face interviews. QL follow-ups were conducted in the spring of 2015 and fall of 2017 (n=98) for group interviews, and in the spring of 2017 and 2018 (n=95) for individual interviews. In terms of additional data sources, a total of 3035 parents consented to own participation, of which 1899 completed a brief online questionnaire at QT baseline in late 2017. School principals completed brief surveys at the same time.

FUTURE PLANS

Both QT and QL arms have planned follow-ups through 2021. Consents were obtained for individual-level linkages of adolescent and parental quantitative surveys to each other, as well as to the information available in multiple national registries and databases. These supplemental data sources will provide key information on additional putative exposures as well as on the long-term health, educational, and social outcomes of the MyLife participants.

Time Trends in the Co-use of Cannabis and the Misuse of Tranquilizers, Sedatives and Sleeping Pills among Young Adults in Spain between 2009 and 2015

The aims of this study were: (a) to estimate time trends in the prevalence of the co-use of cannabis and other cannabis-based products (CBP) with the misuse of tranquilizers, sedatives, and sleeping pills (TSSp) between 2009 and 2015; and (b) to identify the factors associated with the probability of the co-use of CBP with TSSp misuse during this period among Spanish younger adults (15–34 years old). We analyzed data collected from the Spanish National Surveys on Alcohol and Other Drugs (EDADES) in 2009, 2011, 2013, and 2015. CBP co-use with TSSp misuse were the dependent variables. We also analyzed sociodemographic features, self-perceived health status, lifestyle habits, perceived health risk of consumption, and perceived availability of substance using logistic regression models. The prevalence of CBP co-use with TSSp misuse has decreased in Spain. The factors associated with co-use were a lack of education (OR 2.34), alcohol (OR 7.2), tobacco (OR 6.3) and other illicit psychoactive drug (OR 6.5) consumption, perceived non-health risk for the consumption of CBP and TSSp (OR 3.27), and perceived availability of CBP (OR 2.96). Our study identified several factors that appear to affect CBP and TSSp co-use in younger adults, with potential implications for healthcare providers.

Perceived harmfulness of various alcohol- and cannabis use modes: Secular trends, differences, and associations with actual substance use behaviors among Norwegian adolescents, 2007-2015

BACKGROUND

How youth perceive harmfulness of risk behaviors such as substance use relates to their engagement in those behaviors. Yet, little is known about how different substance use modes (i.e., variations in amounts and use frequencies) are perceived. We investigated how adolescent perceptions of harmfulness of various alcohol- and cannabis use modes changed over time, compared to one another, and related to actual substance use behaviors.

METHODS

We examined nationally-representative repeated cross-sectional samples of 16-year olds in Norway, assessed in 2007, 2011, and 2015 (N_Total = 9296) as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Adolescents reported their: 1) lifetime alcohol- and cannabis use, and 2) perceived harmfulness of various alcohol- and cannabis use modes.

RESULTS

Prevalence estimates for perceived harmfulness: 1) remained high and stable, or increased for alcohol use modes, and 2) declined for all cannabis use modes (i.e., using 1-2 times, occasionally, and regularly) since 2007-cohort. High quantity daily drinking was more commonly perceived as harmful than minimal or occasional cannabis use. Even though culturally-relevant use modes (i.e., weekend heavy drinking and experimental cannabis use) were not most commonly endorsed as harmful, only perceptions of those use modes as harmful were inversely associated with actual substance use.

CONCLUSIONS

How adolescents from Norway perceived harmfulness of alcohol- and cannabis use depended on the specific substance, its use modes, and secular cohort. Perceived harmfulness was associated with measures of actual substance use predominantly along the culturally- and adolescent-relevant modes of use.

Is policy 'liberalization' associated with higher odds of adolescent cannabis use? A re-analysis of data from 38 countries

BACKGROUND

Policy makers worldwide face the choice of whether to reform cannabis policy from the 'full prohibition' model. A paper by Shi et al. (2015) suggested that such 'liberalization' is significantly associated with higher odds of adolescent cannabis use.

AIM

To test the validity and reliability of Shi et al's conclusion that the HBSC data show an association between policy 'liberalization' and increased likelihood of adolescent cannabis use.

METHODS

Replication and re-analysis of the same pooled data from three waves of the Health Behaviour in School-aged Children (HBSC) survey (2001/2, 2005/6 and 2009/10). This replicates - as far as possible - the coding and analytical strategy of the Shi et al article. The re-analysis makes some improvements by: excluding a variable ('number of siblings') for which many cases have missing data; including available data from the theoretically relevant case of Sweden for the latter two waves of the HBSC survey, which Shi et al omit; and including random slopes for gender between countries as well as random intercepts for countries in the mixed effects model, as the predictive effect of gender on cannabis use varies across countries.

RESULTS

Shi et al's verbal summary of their findings is not supported by detailed interpretation of their own numerical results. Without making the suggested amendments, it is possible to find a statistically significant association between policy 'liberalization' and higher odds of some measures of adolescent cannabis use. But when these improvements are made, this association becomes statistically non-significant.

CONCLUSION

Using a larger and more theoretically relevant sample of the HBSC respondents and an improved statistical model shows that the HBSC data do not reveal a statistically significant association between policy 'liberalization' and higher odds of adolescent cannabis use.

Neurobiology of substance use in adolescents and potential therapeutic effects of exercise for prevention and treatment of substance use disorders

Substance use (e.g., alcohol, marijuana, opioids, cocaine., etc,) use often initiates during adolescence, a critical period of physiological and social development marked by an increase in risk-taking due, in part, to heightened motivation to obtain arousal from rewards. Substance use during adolescence has been associated with a greater risk of substance use disorders (SUD) in adulthood. Although use rates for most substances have remained relatively stable, the frequency of marijuana use and the perception that regular marijuana use is not harmful has increased in adolescents. Furthermore, the nonmedical use of opioids has increased, particularly in the South, Midwest, and rural low-income communities. Substance use in adolescence has been associated with adverse structural and functional brain changes and, may exacerbate the natural "imbalance" between frontal/regulatory and cortical-subcortical circuits, leading to further heightened impulsive and reward-driven behaviors. Exercise increases growth and brain-derived neurotrophic factors that stimulate endogenous dopaminergic systems that, in turn, enhance general plasticity, learning, and memory. Exercise may help to reinforce the "naïve" or underdeveloped connections between neurological reward and regulatory processes in adolescence from the "bottom up" and "offset" reward seeking from substances, while concomitantly improving cardiovascular health, as well as academic and social achievement. In this review, we provide an overview of the current state of substance use in adolescents and rationale for the utilization of exercise, particularly "assisted" exercise, which we have shown increases neural activity in cortical-subcortical regions and may modulate brain dopamine levels during adolescence, a unique window of heightened reward sensitivity and neural plasticity, for the prevention and adjunctive treatment of SUD.

Who seeks treatment for cannabis use? Registered characteristics and physical, psychological and psychosocial problem indicators among cannabis patients and matched controls

BACKGROUND

There has been an absolute and relative increase in the number of patients with cannabis-related disorders as the principal diagnosis in many countries in recent years. Cannabis is now the most frequently mentioned problem drug reported by new patients in Europe, and cannabis patients constituted one third of all drug treatment patients in 2015. There is limited knowledge with regard to patient characteristics, the extent and types of health and psychosocial problems, as well as their association with long-term outcomes.

METHODS

We analysed indicators of physical, psychological and psychosocial problems of all patients admitted to treatment for cannabis use in Norway in 2009 and 2010 using register data and observed them to the end of 2013. Patient characteristics and outcomes were compared to a randomly drawn control group with corresponding age and gender distribution. Using logistic regression of prospective data, we studied associations between baseline characteristics and work and study status in 2013.

RESULTS

Cannabis patients tended to be relatively young and the large majority were male. They had parents who were less highly educated compared to controls, while there was no difference in migration background. In addition to an increased risk of premature death, nearly half of the patients received a secondary psychological diagnosis and a similar proportion received an additional substance use diagnosis during the 4-5 years of study follow-up. The cannabis patients were less educated than the control group and also less likely to be studying or working at the end of the study period. Entering treatment at a young age, having completed more than secondary education, having a highly-educated mother and not having a secondary diagnosis were factors that were positively associated with being in education or employment at the end of follow-up.

CONCLUSIONS

Data covering the entire Norwegian population of patients admitted primarily for cannabis-related problems showed comprehensive and complex patterns of physical, psychological and psychosocial problems. The prevalence and extent of these problems varied markedly from those of the general population. Work and study outcomes following treatment depended on the seriousness of the condition including co-morbidity as well as social capital.

Commentary on Burdzovic Andreas & Bretteville-Jensen (2017): Cannabis use opportunities-an under-researched factor in substance use epidemiology

Assessment of realistic cannabis use opportunities increases understanding of population-level changes in cannabis use behaviors among adolescents. In an era of rapidly changing cannabis policy, more nuanced models of cannabis use, exploring the pathway from first use opportunity to incident cannabis use, can inform the development of public health strategies.