BACKGROUND:This research examined whether area-level social fragmentation was associated with adolescent depressive and anxiety symptoms, and whether heterogeneity by gender was present. METHODS:Cross-sectional adolescent data (n = 66, 434) from wave 6 (2017-18) of the COMPASS study were used. Demographic information, depression, and anxiety were reported via questionnaire. Census division social fragmentation was derived from four census variables (proportions of renters, movers in last year, single tenant households, and unmarried couples). Multilevel linear regression analyses were performed to account for students nested within schools (n = 122), who were nested within census divisions (n = 40) while accounting for province, student, and census division characteristics. Interaction terms were added to adjusted models to examine heterogeneity by gender. RESULTS:In adjusted models, a one standard deviation increase in social fragmentation was associated with higher depressive symptoms (β = 0.39, 95% CI: 0.04, 0.75) and anxiety symptoms (β = 0.39, 95% CI: 0.03, 0.75). Findings became non-significant in models with province as fixed effect. The slopes were lower for females (depression: β = -0.18, 95% CI: -0.28, -0.09; anxiety: β = -0.26, 95% CI: -0.36, -0.16) than for males. CONCLUSION:Social fragmentation may be a contextual risk factor for adolescent depression and anxiety; however, more research is needed investigating social fragmentation at multiple scales and over time. Understanding potential mechanisms for differences between males and females is also needed.

ObjectiveThis study examined whether schools' engagement with their local public health unit (PHU) regarding mental health was associated with adolescent anxiety and depression.MethodsLinked longitudinal data from 2017-18 and 2018-19 of the COMPASS study was used. Adolescent (n = 27 473) anxiety and depressive symptoms were self-reported via questionnaire. School (n = 112) engagement with their local PHU regarding mental health was reported via administrative survey. Multilevel logistic regression was used to model the association between school PHU engagement and adolescent anxiety and depression.ResultsAdolescents attending schools that engaged with their local PHU had greater odds of anxiety at baseline (OR = 1.30, 95%CI: 1.10, 1.53) and the probability was higher over time compared to adolescents who attended schools with no PHU engagement. Similar results were found regarding the odds of depression at baseline (OR = 1.18, 95%CI: 1.02, 1.36). No differences in the likelihood of depression over time were observed.ConclusionBased on these findings, school engagement with their local PHU may be associated with student anxiety and depression. However, more research over a longer time frame and with more detailed measures of PHU engagement is needed.

BackgroundYouth with chronic physical illness (YwCPI) are more vulnerable to developing psychopathology than their healthy counterparts. Families are negatively impacted by CPI diagnosis; however, research has neglected siblings. This study assessed the continuity of symptoms of psychopathology in YwCPI and siblings.MethodsData come from MY LIFE, a prospective study that includes five waves (T1 through T5) among 171 YwCPI and their siblings. Two cross-lagged panel models were computed to evaluate continuity of internalizing and externalizing symptoms. Autoregressive pathways measured homotypic continuity by predicting changes in the same outcome across assessments, while cross-lagged pathways appraised heterotypic continuity by testing if one symptom predicted another at later time points.ResultsSignificant (p < 0.05) autoregressive paths were detected between all time points for internalizing (YwCPI: β = 0.22-0.78; sibling: β = 0.23-0.75) and externalizing (YwCPI: β = 0.40-0.75; sibling: β = 0.26-0.78) symptoms. In YwCPI, internalizing symptoms at T1 predicted externalizing symptoms at T2, while in siblings an indirect effect was observed from T1 externalizing to T2 internalizing symptoms.ConclusionHomotypic continuity was strong and similar for YwCPI and siblings. Patterns of heterotypic continuity were of smaller magnitude and differed between the two groups. The presence of internalizing and externalizing symptoms in YwCPI and siblings support the inclusion of siblings in family-centred care.

According to McLeroy’s socio-ecological model, inter-organizational collaboration is important in shaping population health. This study aimed to investigate the association between public health unit (PHU) collaboration in secondary schools and student substance use over time. Data from the Cannabis, Obesity, Mental health, Physical activity, Alcohol, Smoking, and Sedentary behaviour (COMPASS) study were used to identify student-level substance use behaviours and school-level PHU engagement. Substance use was measured as self-reported use of alcohol, cannabis, cigarettes, and electronic cigarettes. Multilevel logistic regressions accounted for the hierarchical data structure. This study included 16,575 students attending 68 Canadian schools from 2016/2017 to 2018/2019. Among these schools, 65

Mental disorders tend to cluster within families, yet the majority of research focuses on one child per family. There is a paucity of research examining the impact of a child’s mental disorder on siblings. This scoping review addresses the following questions: (i) How do mental disorders in children impact the mental health of their sibling(s)? (ii) Which resources exist that address the needs of siblings of children with mental disorders? We searched eight databases for empirical studies and screened for those published since 2011. n = 27 studies were included; n = 21 studies addressed research question one and n = 6 addressed research question two. Pertaining to research question one, quantitative studies found that siblings of children with mental disorders are at risk for developing mental health problems or psychopathology themselves and experience a wide range of symptoms across many diagnostic categories. Qualitative studies reported siblings’ negative emotions and experiences (e.g., confusion about child’s disorder, fearful of violence from the child). Pertaining to research question two, we found a paucity of research (n = 6 studies) that assessed resources or interventions for siblings, indicating that there is likely a lack of interventions available for siblings. Future research should look to use more robust quantitative study designs (e.g., longitudinal, mixed-methods) in diverse samples and qualitative methodologies that can investigate particularly concerning instances. While we did identify that sibling interventions exist, those created with sibling and family voices may be better positioned to address sibling’s needs.

Background:Underage drinking remains a major public health concern worldwide, contributing to a wide range of health and social harms. While adolescent alcohol use has been widely studied, there is limited evidence on how adolescents obtain alcohol and how these sources relate to drinking behaviours. Methods:This cross-sectional analysis used data from 8,507 Grades 9-12 students participating in the 2022-2023 COMPASS study across 66 schools in Canada. Analyses were restricted to students who reported alcohol use in the past 12 months. Proportional odds mixed models assessed associations between alcohol sources and two ordinal outcomes: drinking frequency and binge drinking frequency, adjusting for individual- and school-level covariates. Results:Parents/guardians were the most frequently reported source of alcohol (32%), followed by parties or events (22%) and purchasing or receiving alcohol from others (17%). Parental provision was most common among occasional or infrequent drinkers, whereas commercial sources (stores, restaurants, or bars) were prominent among frequent drinkers and binge drinkers. Adjusted models showed that obtaining alcohol from commercial sources was associated with a more than a fivefold increase in the odds of frequent and binge drinking compared with parental supply. Conclusions:These findings highlight distinct patterns in how Canadian adolescents report accessing alcohol, underscoring the importance of prevention strategies that address both social and commercial sources. Interventions focused on family environments, party settings, and retail access may help reduce opportunities for alcohol acquisition and mitigate the risk of higher-risk drinking behaviours among youth.

INTRODUCTION:The objectives of this study were to examine: (1) the cross-sectional and longitudinal associations between social media (SM) time and mental health outcomes among a large sample of Canadian adolescents (ages 12-18) and (2) if associations are moderated by gender. METHODS:Data from the Cannabis, Obesity, Mental health, Physical activity, Alcohol, Smoking, and Sedentary behaviour (COMPASS) study were used to conduct two cross-sectional analyses (2021/2022: n = 58,289; 2022/2023: n = 44,777) and a linked longitudinal analysis (2021/2022 to 2022/2023: n = 26,743). The exposure variable was time spent browsing/scrolling SM (cross-sectionally), and the change in SM time from baseline to follow-up (longitudinally). The outcome variables were anxiety, depression, flourishing, personal relationships, and emotional regulation (measured at follow-up in longitudinal models). The moderator variable was gender, categorized into cisgender girls, cisgender boys, and transgender/gender-diverse adolescents. Multilevel linear modeling was conducted. RESULTS:An additional hour/day of SM (cross-sectionally) and one additional hour/day of SM from baseline to follow-up (longitudinally) was significantly associated with increased depression and anxiety symptoms, decreased flourishing, and poorer personal relationships and emotional regulation at follow-up. Gender was a significant moderator of SM time and mental health outcome associations cross-sectionally, but gender did not moderate change in SM time and mental health outcome associations longitudinally. Cisgender girls experienced significantly larger negative associations between SM time and mental health outcomes in comparison to cisgender boys and transgender/gender-diverse adolescents cross-sectionally. CONCLUSIONS:Among Canadian adolescents, SM time was associated with poorer mental health outcomes both cross-sectionally and over 1 year.

BACKGROUND:Research suggests that adolescents belonging to equity-deserving populations often experience pronounced health consequences due to barriers they face at the intersection of their social identities. Our study examined how current cannabis use varies among ethno-racial groups by gender identities. METHODS:Cross-sectional data from 68,533 adolescents in the 2022/2023 COMPASS survey were analyzed. Logistic regression analysis using generalized estimating equations (GEEs) was conducted to determine the likelihood of current cannabis use among diverse ethno-racial groups stratified by gender identities. All models accounted for clustering by province, and were adjusted for age, perceived relative affluence, current binge drinking, and current e-cigarette use. RESULTS:Among cisgender girls, the highest risk group for current cannabis use were Multiethnic (aOR: 1.26, 95% CI: 1.18-1.35), Black/African and Caribbean (aOR: 1.05, 95% CI: 1.04-1.07), and "other ethno-racial group" (aOR: 1.55, 95% CI: 1.43-1.67) youth relative to White/European cisgender girls; the lowest risk group included East Asian, South Asian, Southeast Asian youth. Cisgender boys displayed similar risk profiles to cisgender girls. However, current cannabis use was significantly more likely among all racialized transgender and gender-diverse youth, except for Southwest Asian and North African, and Southeast Asian youth, relative to their White/European counterparts. CONCLUSIONS:Current cannabis use risk profiles varied by ethno-racial and gender identities. The findings suggest that culturally tailored education and prevention approaches incorporating an intersectional lens are warranted to address cannabis use among adolescents at risk.

BACKGROUND: Youth with chronic physical illnesses (YwCPI) generally report lower health-related quality of life (HRQL) compared to healthy peers. Despite the pervasive effects of CPI within families, research on siblings is limited. This study modelled 48-month trajectories of change in HRQL in YwCPI and siblings and identified predictors of these trajectories. METHODS: Data come from the MY LIFE study, comprising 171 YwCPI, and their age-matched siblings. HRQL was assessed at five time points over 48 months using the KIDSCREEN-27, which includes five subscales: physical, psychological, autonomy, peers and school. Latent class growth analysis modelled trajectories of change separately for YwCPI and siblings, and multinomial regression models identified predictors of trajectory group membership. RESULTS: YwCPI generally reported lower HRQL than siblings across physical, psychological, autonomy, peers, and school. Most youth had stable trajectories with changes occurring primarily between baseline and 12 months. Significant predictors of trajectory group membership included baseline HRQL, parent stress, age, and household income. CONCLUSION: A greater proportion of siblings, compared to YwCPI, had improving trajectories of change in HRQL, likely reflecting adaptation within the family system. Early changes suggest a window for intervention, supporting the importance of timely support. Shared family environment, caregiving responsibilities, and parental stress could influence HRQL trajectories, underscoring the need for family-centered care. These findings highlight that while many youth have stable HRQL, targeted support is crucial for those with persistently low, or declining outcomes.

Cultivating positive school climates has been recognized as a global and Canadian priority for adolescent health, academic achievement, and development. Feeling welcome at school is an early contributor to overall positive school climate, although detailed understanding of different reasons adolescents may not feel welcome at school at the population-level is limited. The present study examined the prevalence of reasons students felt unwelcome at school and the characteristics of students endorsing each reason. Self-report survey data were used from students (N = 15,610, Mage ± SD = 15.6 ± 1.2, 48.1% girls) from 41 secondary schools in Ontario, Canada, that participated in the 2022-2023 wave of the COMPASS study. Frequencies calculated the prevalence of each reason for feeling unwelcome at school. Overall, 63.4% of students felt unwelcome at school for at least one reason. Appearance (29.6%), another reason (23.3%), marks at school (19.3%), emotional/psychological challenge (15.7%), and race/ethnicity/culture (10.6%) were the most common reasons for feeling unwelcome at school. Overweight perception, gender diverse identity, and low perceived relative financial affluence were overrepresented in participants that felt unwelcome at school relative to the overall sample. The many reasons adolescents feel unwelcome at school need to be addressed as schools focus on building positive and inclusive school climates, and should be considered across multiple levels (e.g., teacher training, students' learning materials, policy).

BACKGROUND:There is a paucity of literature regarding income inequality and adolescent movement behaviours (physical activity, sedentary behaviours, sleep). This study examined whether income inequality was associated with meeting Canadian 24-Hour Movement Guidelines (24HMG) recommendations among adolescents over time. METHODS:Longitudinal data from adolescents (n=9299) in the Cannabis, Obesity, Mental health, Physical activity, Sedentary behaviour and Smoking study (2016-2017 to 2018-2019) were linked with income data at the census division (CD) level from the 2016 Canadian Census. Adolescents (aged 13-19 years) reported on their physical activity, sleep duration and screen time via questionnaire. Gini coefficients were calculated at the CD level using after-tax household income from the 2016 Canadian Census. Multilevel logistic regression analyses were performed to test the association between income inequality and meeting several 24HMG recommendations. RESULTS:The joint effect (income inequality*time) was significant for meeting the sleep duration recommendation (2017-2018 OR=0.83, 95% CI 0.74, 0.92; 2018-2019 OR=0.77, 95% CI 0.70, 0.86; p<0.0001), meeting any two recommendations over time (2017-2018 OR=0.97, 95% CI 0.86, 1.09; 2018-2019 OR=0.85, 95% CI 0.75, 0.97; p=0.0402) and meeting combined sleep and physical activity recommendations (2017-2018 OR=0.93, 95% CI 0.82, 1.06; 2018-2019 OR=0.82, 95% CI 0.71, 0.94; p=0.0200). Joint effects (income inequality*time) were not significant (p>0.05) for screen time or physical activity independently of sleep. CONCLUSION:Adolescents attending schools in areas with greater income inequality may be at higher risk for inadequate sleep and combined short sleep and physical inactivity.

We explored adolescents' perceived barriers and facilitators to accessing formal and informal mental health support during the COVID-19 pandemic response. In this qualitative descriptive study, 30 semi-structured online interviews were conducted between June and August 2021 with adolescents (13-18 years old, 53.3% girls) living in Canada and analyzed using reflexive thematic analysis. Four themes were constructed: 1) perceptions of others being unable to understand and/or help them, 2) discomfort disclosing concerns to a potential helper, 3) concerns about parents and/or peers finding out due to questioned privacy and confidentiality, particularly in the school context, and 4) perceptions about their capacity to access formal support. Themes were related to participants' perceptions of parent/guardian and peer beliefs regarding mental health and help seeking. Parents were experienced as gatekeepers to adolescents' access to mental health services and resources. This study highlights the importance of considering adolescent development in accessibility, particularly their increasing autonomy. Despite schools often being regarded as the ideal location to first connect youth with mental health services, adolescents continue to experience many barriers to seeking and accessing help within this context. Results have implications for improving access to mental health support for adolescents beyond the pandemic, both within and outside of schools.

Increases in adolescent loneliness were a significant concern during the lockdowns of the COVID-19 pandemic. We use longitudinal survey data from the Cannabis Use, Obesity, Mental Health, Physical Activity, Alcohol Use, Smoking, and Sedentary Behavior study from 2017 to 2023 to assess whether increases in loneliness correspond to lockdowns, whether different cohorts differ in the trajectories of loneliness ratings and whether social support and relationships impact the course of loneliness throughout secondary school. We compared linear latent growth models and latent basis growth models of annual repeated measures of loneliness from three 4-year cohorts of Canadian high school students (N = 5,237, female = 3,166, 80.42% White). For the 2017-2021 cohort, a linear model fit best, while nonlinear models were the best fit for the 2018-2022 and 2019-2023 cohorts. Ratings of loneliness were highest at the beginning of the COVID-19 pandemic across all three cohorts and stabilized in the years following. Growth mixture models identified groups with differing trajectories of loneliness where lowest loneliness was associated with positive relationship quality of family and friends. Overall, the study demonstrated heterogeneity in loneliness trajectories across time between and within cohorts. The patterns were consistent with increases during COVID-19 lockdowns and a return to typical levels as social restrictions eased. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

BACKGROUND:Public health units (PHU) require adequate funding to service the needs of their community. This study examined the association between PHU funding and adolescent mental health trajectories from 2018-19 to 2020-21 in Ontario, Canada. METHODS:Longitudinal adolescent data from the Cannabis, Obesity, Mental health, Physical activity, Alcohol, Smoking, and Sedentary behaviour (COMPASS) study (n = 6043) was used. Adolescents reported on depression and anxiety symptoms via questionnaire. Data on funding from 12 PHUs was obtained from the Ontario Public Health Information Database. We used multilevel growth curve analyses to estimate whether PHU funding modified trajectories of depressive and anxiety symptoms while adjusting for student, school, and area-level covariates. We also tested for heterogeneity by gender and performed gender stratified analyses. RESULTS:PHU funding modified depression trajectories. Differences in depression scores by level of PHU funding were not significant at each time point. However, students attending schools in areas with lower PHU funding had smaller rates of growth in depression from 2018-19 to 2019-20 (Low PHU: ∂ = 0.50, 95 % CI: 0.27, 0.74; High PHU: ∂ = 1.10, 95 % CI: 0.81, 1.39), but larger rates of growth from 2019-20 to 2020-21 (Low PHU: ∂ = 1.66, 95 % CI: 1.32, 2.00; High PHU: ∂ = 0.70, 95 % CI: 0.35, 1.05). Findings were similar in female stratified models. PHU funding did not modify anxiety trajectories. CONCLUSION:Trajectories of adolescent depression symptoms, particularly females, during the COVID-19 pandemic may have been modified by the level of PHU funding. More research over a longer period and in different jurisdictions is needed.

This study examined the associations between internalized weight bias and physical activity (resistance training, moderate-to-vigorous physical activity; MVPA) across weight perceptions over one year among Canadian adolescents. Participants in Years 10 (T1; 2021-2022) and 11 (T2; 2022-2023) of the COMPASS study completed a cross-sectional self-report survey each year (N = 23,574, Mage = 14.3 (SD = 1.2), 51.5 % cisgender girls). Linear mixed effects multilevel models stratified by weight perception (underweight, about the right weight, overweight) tested the association between T1 internalized weight bias and T2 physical activity after controlling for province, gender, ethnicity, perceived affluence, age, and T1 physical activity. Adolescents with overweight perceptions reported higher internalized weight bias (ηp2 = .05) and lower MVPA (ηp2 = .004) and resistance training (ηp2 = .01) than adolescents with lower-weight perceptions. For adolescents with underweight and about the right weight perceptions, internalized weight bias was associated with more MVPA [b(SE) = 6.8(3.0); 3.7(1.4)] and resistance training [b(SE) = .33 (.12); .11(.06)] one year later compared to adolescents reporting no internalized weight bias. Physical activity levels were not different across levels of internalized weight bias among adolescents with overweight perceptions. The differing associations between internalized weight bias and physical activity across weight perceptions may relate to broader anti-fat attitudes and experiences of stigma that uniquely impact adolescents with overweight perceptions. Future research should consider the physical activity motivations associated with internalized weight bias.

BackgroundHigher exposure to adverse childhood experiences (ACEs) has been shown to worsen the effect of COVID-19 stress on mental health problems in the early phase of the COVID-19 pandemic among young adults. This study extends that research by examining depression, anxiety, hostility, and perceived stress trajectories across successive phases of the COVID-19 pandemic in a prospective, multi-wave panel study using data collected pre-COVID-19 pandemic onset, Early pandemic, Peak pandemic, and Post-Peak pandemic.MethodsThe baseline data come from the Niagara Longitudinal Heart Study (NLHS) and the three COVID-19 waves come from a sub-study of the NLHS examining the specific impact of the pandemic. Using a Bayesian multivariate mixed-model regression framework, 171 participants who responded to at least one wave of the COVID-19 sub-study were included.ResultsParticipants with higher ACE scores and high COVID-19 stress had elevated trajectories of several poor mental health measures that stayed higher than other groups across all waves of data collection.DiscussionYoung adults who reported higher ACEs were more susceptible to subsequent stress exposure, highlighting a specific, high-risk group who may benefit from targeted intervention programs during times of crisis such as the COVID-19 pandemic.

OBJECTIVE:Vaping among adolescents has surged in recent years, underscoring the need to identify intentions and motivating factors behind vaping. Although weight management behaviors have been associated with vaping, the largely cross-sectional evidence precludes understanding of how these behaviors may relate to and reinforce each other over time. This study explored the bidirectional associations between vaping and changed eating to manage weight and shape over 3 years of adolescence. METHOD:Adolescents from the Cannabis, Obesity, Mental Health, Physical Activity, Alcohol, Smoking, and Sedentary Behaviour (COMPASS) Study (N = 8,960, M age = 13.8 [SD = 1.1], 55.5% cisgender girls) completed self-report surveys annually for 3 years (Time 1 [T1] = 2020/2021, T2 = 2021/2022, T3 = 2022/2023). Data were analyzed using random-intercept cross-lagged panel models with full information maximum likelihood. RESULTS:Increases in vaping were observed over time (20.9% at T1, 40.0% at T3), and 30% of adolescents changed their eating habits to manage their weight/shape each year. Weak but significant associations were generally observed, such that cisgender girls who changed their eating to manage weight/shape engaged in more vaping the following year (betaT1-T2 = .05; betaT2-T3 = .05). Conversely, cisgender girls and boys with a higher vaping frequency reported more days of changing eating to manage weight/shape 1 year later (betaT1-T2 = .02 and .04, betaT2-T3 = .05 and .06). CONCLUSIONS:The bidirectional relationship between vaping and weight-related eating behaviors underscores the value of addressing these habits as interconnected behaviors, informing the development of targeted public health policies, preventative measures, and intervention strategies to support health and reduce the adoption of vaping among adolescents.

Mental ill-health is a leading contributor to adolescent disease burden, with females and socioeconomically disadvantaged youth facing higher rates of mental disorders. Adolescence is a key period for the development of lifestyle risk factors for mental disorder, which are increasingly being recognized as important and novel population-level preventive intervention targets. We used decision trees to examine combinations of sociodemographic factors and the "big six" lifestyle behaviours (poor sleep, physical inactivity, sedentary screen time, poor diet, alcohol use and smoking) prospectively associated with worse anxiety, depression and psychological distress scores. We examined survey data from 3978 Australian adolescents (mean age 14.6 at baseline) who participated in the Health4Life study in 2021 and 2022. CART decision trees were run to rank the relative importance of each risk factor and to identify combinations of risk factors that characterize groups with highest anxiety (PROMIS-AP), depression (PHQ-8A) and psychological distress (K6) scores 1 year later. Gender was the primary differentiator of risk, with cisgender females and gender diverse adolescents having consistently worse mental ill-health scores than cisgender males. Inadequate sleep and excessive sedentary recreational screen time were consistently the top lifestyle factors and often emerged in combination to characterize higher risk groups. These findings offer new insights into relative importance of various lifestyle risk factors in adolescent mental health and highlight both the increased risk from engaging in combinations of unhealthy lifestyle behaviours and the need for targeted prevention and early intervention initiatives to reduce the gender gap in adolescent mental health.

Concerns have increased about online gambling among adolescents. Poor mental health may place adolescents at increased risk of engagement in online gambling, however, longitudinal evidence is limited. The purpose of this study was to examine how mental health relates to engagement in online gambling one-year later in a large cohort of adolescents. We used 2-year prospective survey data from 26,818 students in Grades 9 to 11 (secondary III-IV in Quebec) attending 121 secondary schools in four Canadian provinces (Alberta, British Columbia, Ontario, and Quebec) who participated in the COMPASS study during the 2017/18, 2018/19, and/or 2019/20 school years. Generalized linear mixed models were used to examine the likelihood of online gambling one-year later by baseline mental health outcomes (depressive symptoms, anxiety symptoms, psychosocial well-being, emotional dysregulation), controlling for student sex, grade, race, weekly spending money, and baseline online gambling. Online gambling in the past 30-days was reported by 2.1

Background:This paper compares risk profiles for cannabis use among large samples of youth in the school years preceding (2017-18, T1) and four years following (2021-22, T2) cannabis legalization in Canada. Methods:COMPASS Study data from students across 85 secondary schools that participated in both the T1 and T2 waves were used. A novel classification tree approach examined current cannabis use (past 30-day), modelling complex interactions among multiple risk factors simultaneously in the T1 and T2 samples. Results:At T1, 15.0 % of students reported current cannabis use, compared to 12.3 % of students at T2. The classification tree at T1 identified six unique risk profiles. The highest risk group (Pr = 0.269) was large (30.4 % of the sample) and comprised students who placed lower value on getting good grades and spent 45 min or more per day texting. The classification tree at T2 identified 11 unique risk profiles. The highest risk group (Pr = 0.27) was large (18.8 % of the sample) and comprised students who again placed lower value on getting good grades but also reported not eating breakfast daily and having elevated anxiety. Discussion:Cannabis never use increased and current cannabis use slightly decreased among underage youth in a 4-year period spanning cannabis legalization. The relative importance ranking of risk factors for predicting current cannabis use changed considerably from T1 to T2. This suggests that prevention efforts need to adapt over time to target the relevant risk factors associated with cannabis use.