A Behavioural Genetic Model of the Mechanisms Underlying the Link Between Obesity and Dimensional Measures of Attention-Deficit/Hyperactivity Disorder (ADHD)

Objective: The purpose of this study was to investigate genetic and psycho-behavioural mechanisms contributing to the strong ADHD symptom-obesity association. Genetic variants associated with hypo-dopaminergic functioning have been implicated in ADHD, particularly the 7-repeat allele of a VNTR located on the DRD4 gene, likely due to the receptor’s predominance in the prefrontal cortex. Based on this evidence, some experts have suggested that a shared aetiology of a dysfunctional dopamine (DA) system is responsible for the link. However, this conflicts with accumulating evidence that it is actually an amplified DA signal that increases the risk for overeating and weight gain due to a stronger appetitive response to food cues. It seems plausible that individuals with ADHD symptoms who are predisposed overeat are those who also possess a high sensitivity to, and greater motivation to seek out, rewarding stimuli, as reflected by increased DA availability in the brain reward pathways. Accordingly, the current study tested the hypothesis that symptoms of ADHD, predicted by hypo-dopaminergic functioning in the prefrontal cortex, in combination with an enhanced appetitive drive, predict hedonic eating, and in turn, higher BMI. Methods: Functional markers of the DRD2 and DRD4 were genotyped to determine their contributions to ADHD symptoms and various indices of hedonic eating, respectively. The model was tested using Structural Equation Modeling procedures in a general population sample (n=421 adults) representing a broad range of body mass index (BMI) values. Results: Overall, the fit indices indicated that the proposed model was a good fit to the data. Controlling for education level, all parameter estimates were in the expected direction and statistically significant with the exception of the pathway from the DRD4 marker to ADHD symptoms. The indirect effect was significant, indicating that overeating mediated the association between ADHD symptoms and BMI. Conclusions: Results lend support to the hypothesis that overeating and an elevated DA signal in the ventral striatum – representative of a greater reward response – are responsible for the link between ADHD symptoms and obesity. The current study was the first to connect the most prominent and supported theories of ADHD with evidence-based models of hedonic eating

Do weight perception and bullying victimization account for links between weight status and mental health among adolescents?

Background: The purpose of this study was to explore whether the way youth perceive their weight and their experiences of bullying victimization account for the increased risk of depression and anxiety symptoms, and poor psychosocial well-being, associated with overweight/obesity in a large sample of Canadian secondary school students. We also explored if associations differed by gender. Methods: We used cross-sectional survey data from year 7 (2018–19) of the COMPASS study. The sample included 57,059 students in grades 9–12 (Secondary III-V in Quebec) at 134 Canadian secondary schools (Alberta, British Columbia, Ontario, Quebec). First, multiple regression models tested associations between body mass index (BMI) classification and mental health outcomes (anxiety [GAD-7] and depression [CESD-10] symptoms, and psychosocial well-being [Diener’s Flourishing Scale]). Second, weight perception and bullying victimization were added to the models. Models were stratified by gender and controlled for sociodemographic covariates and school clustering. Results: When weight perception and bullying victimization were added to the models, obesity BMI status no longer predicted internalizing symptoms and flourishing scores relative to normal-weight BMIs. Students with ‘overweight’ or ‘underweight’ perceptions, and experiences of bullying victimization in the past month, reported higher anxiety and depressive symptomatology, and lower flourishing levels, in comparison to students with ‘about right’ weight perceptions and without experiences of bullying victimization, respectively, controlling for BMI status. Results were largely consistent across boys and girls. Conclusions: Results suggest perceptions of weight and experiences of bullying independently contribute to differences in mental health outcomes by weight status among youth. Continued efforts targeting weight-based bullying and weight bias, and the promotion of body size acceptance and positive body image, may help reduce the risk of mental illness and poor mental health among adolescents.Brock Library Open Access Publishing Fun

Interrelationships among depression, anxiety, flourishing, and cannabis use in youth

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.addbeh.2018.10.007 © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Aims The objective of the study was to examine if depression or anxiety was associated with youth cannabis use; and investigate whether flourishing moderates these associations. Methods Students (N = 8179) were recruited from 10 secondary schools (grade 9–12) in Ontario and British Columbia, Canada Self-report questionnaires were used to assess symptoms of depression [CESD-R-10], anxiety [GAD-7], flourishing [Deiner's Flourishing Scale] and cannabis consumption using measures that assess cannabis ever use and frequency of use. Logistic regression and product-term interactions were used to examine the associations between mental health and youth cannabis use, and the potential moderating effect(s) of flourishing. Results In our sample, 33% of participants had ever used cannabis, 51% and 38% reported elevated depressive and anxiety symptoms, respectively. Associations between depression, anxiety, and cannabis use were no longer significant when flourishing was added to the models. In addition, there was no evidence suggesting a moderating effect of flourishing as all interactions were not statistically significant. Instead, robust associations were found between flourishing and cannabis use: mental health and cannabis ever use, mental health and cannabis use frequency. Conclusions Indicators of mental wellbeing, such as flourishing, appear to be associated with a lower likelihood of cannabis use, even after controlling for depression and anxiety. Results suggest prevention strategies for youth cannabis use should aim to foster mental wellbeing among all youth, rather than exclusively targeting those experiencing mental health problems. Future longitudinal studies should test the sequential relationship between cannabis use and changes in both positive and negative mental health

School start time changes in the COMPASS study: associations with youth sleep duration, physical activity, and screen time

The final publication is available at Elsevier via https://doi.org/10.1016/j.sleep.2018.09.020� 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Background To date, no longitudinal population-based studies of school start times have been conducted within Canada. School schedule changes provided an opportunity to examine start times in association with youth sleep, physical activity, and screen use over time. Methods This longitudinal study included grade 9�12 students attending 49 Ontario secondary schools that participated in at least two consecutive years of the COMPASS study (2012�2017). Fixed effects models tested whether differences in within-student change in self-reported sleep duration, moderate-to-vigorous physical activity, and screen time were associated with school start time changes, adjusting for student- (grade, sex, ethnicity, spending money) and school-level covariates (median income, urbanicity, geographical area). Results Thirteen start time changes of 5�10�min were reported. Ten-minute advances at earlier clock times (8:30 AM�8:20 AM; 8:40 AM�8:30 AM) were associated with steeper sleep duration declines than schools with consistent start times but had no effect at later times (9:00 AM�8:50 AM). While sleep change did not differ with 5-min�delays, 10-min�delays (8:50 AM�9:00 AM) were associated with additional sleep (23.7�min). Apart from one school that shifted from 8:30 AM to 8:35 AM, in which screen time and physical activity decreased more steeply, no effect was found for screen time, and 5-min�delays were associated with more physical activity (10.9�min) and advances with less activity (_8.0�min). Conclusions Results support start time delays as a valuable strategy to help ameliorate sleep debt among youth. Interference with physical activity or increased screen time appear unlikely with modest schedule changes. Potential adverse impacts on sleep require consideration with 10-min�advances.Canadian Institutes of Health Research Institute of Nutrition, Metabolism and Diabetes [grant OOP-110788]Canadian Institutes of Health Research Institute of Population and Public Health [grant MOP-114875]Canadian Institutes of Health Research Project Grant [grant PJT-148562]Canadian Institutes of Health Research New Investigator Salary AwardCanadian Institutes of Health Research Doctoral Research Awar

Establishing spirituality as an intermediary determinant of health among 42,843 children from eight countries

The World Health Organization (WHO) Commission on the Social Determinants of Health (CSDH) conceptual framework identifies socio-economic position as a structural determinant of health. Recognized intermediary determinants include biological, behavioural, and psychosocial factors. We examined whether connections afforded by a healthy spirituality potentially act as unrecognized intermediary determinants in adolescent populations, contributing to inequities in mental health. Reports from 42,843 children (21,007 boys, 21,836 girls) from eight countries who participated in the 2017–2018 Health Behaviour in School-aged Children (HBSC) study were used to describe correlations between family affluence and positive levels of mental health, using a cross-sectional design. Based on the CSDH conceptual framework and multivariable regression analyses, we then examined whether these associations were mediated by spiritual health. Connections afforded by a high level of spiritual health were universally correlated with positive mental health status. In three Western European nations (England, Scotland, and Wales) and Canada affluence was correlated with better mental health and this was partially mediated by spiritual health. Among the four Eastern European countries (Latvia, Lithuania, Moldova, Poland), our findings did not support aspects of the CSDH framework that focus on affluence as a direct determinant of health. Spiritual health potentially is an intermediary determinant of children's health in some Western countries, but not in Eastern countries. The universality of social determinants of health models and the measures used in their evaluation require careful assessment across cultures, political contexts, and health outcomes

Les abus occasionnels d'alcool en lien avec le rendement scolaire, l’investissement dans les études et les aspirations et attentes en matière de scolarité : une étude longitudinale chez les élèves du secondaire ayant participé à l’étude COMPASS

Introduction : Les liens longitudinaux entre la pratique de l'abus occasionnel d'alcool et l’investissement dans les études, le rendement scolaire et les aspirations et attentes en matière de scolarité ont été examinés au sein d'une cohorte d’élèves du secondaire. Méthodologie : Des données appariées tirées de l’année 1 (A1 : 2012-2013), l’année 2 (A2 : 2013-2014) et l’année 3 (A3 : 2014-2015) de l’étude COMPASS (N = 27 112) ont été utilisées dans différents modèles à équation d’estimation généralisée (EEG) multinomiaux pour vérifier la probabilité relative des réponses à sept indices liés aux études chez les élèves commençant à s’adonner aux abus occasionnels d'alcool à différentes fréquences, après ajustement en fonction du sexe, du niveau scolaire, de l’origine ethnique et de l’usage du tabac, ainsi que de la moyenne individuelle du prédicteur et de toutes les covariables évoluant dans le temps. Résultats : Parmi les élèves qui n'avaient jamais abusé occasionnellement d'alcool au départ, ceux qui ont dit s’adonner régulièrement à ces abus par la suite étaient relativement moins susceptibles de faire leurs devoirs, d’assister à leurs cours et de valoriser les notes élevées et d’en obtenir, des abus occasionnels d'alcool plus fréquents conduisant généralement à des risques relatifs plus élevés. Les élèves qui avaient dit ne jamais s’adonner aux abus occasionnels d'alcool au départ et qui ont déclaré le faire « rarement ou de manière sporadique » un an ou deux ans plus tard étaient, curieusement, plus susceptibles de vouloir poursuivre des études postsecondaires. Ceux qui ont déclaré avoir commencé à s’adonner aux abus occasionnels d'alcool « une fois par mois » aspiraient également davantage à obtenir un diplôme collégial ou un diplôme de premier cycle universitaire qu’un diplôme d’études secondaires, mais n'aspiraient pas plus à un diplôme de deuxième cycle universitaire ou plus. Aucune aspiration n'a été associée à ceux qui ont déclaré avoir commencé à s’adonner « toutes les semaines » aux abus occasionnels d'alcool. Conclusion : D'après nos résultats, les élèves qui commencent à s’adonner aux abus occasionnels d'alcool ont un faible rendement scolaire et s’investissent peu dans leurs études, ce qui peut nuire à l’atteinte de leurs objectifs scolaires. Cette étude vient rappeler à quel point la prévention de la consommation de substances doit être considérée comme une priorité en matière d’éducation, puisque les efforts faits dans ce sens pourraient également favoriser la réussite scolaire

Predictors of One-Year Change in How Youth Perceive Their Weight

Overall, perceptions of being at “about the right weight” appear advantageous for youth physical and mental health, regardless of BMI classification, whereas perceptions at either extreme (overweight or underweight) may negatively impact health behaviours and mental health. Instead of considering weight misperceptions as problematic, some researchers have proposed that underestimations of weight status may offer resiliency among individuals with overweight or obesity. Promoting “about right” WPs and preventing change to overweight or underweight perceptions may offer an effective public health strategy for supporting youth health over time. However, limited prospective evidence exists on factors that shape perceptions of weight status over time. The current study examined modifiable predictors of one-year change in weight perception among youths. We used 2-year linked data of 18,112 grade 9–12 students from Year 3 (Y3:2014–2015) and Year 4 (Y4:2015–2016) of the COMPASS study. Generalized Estimating Equation models tested screen use, physical activity, and bullying victimization as predictors of change from perceptions of “about the right weight” to “overweight” or “underweight” perceptions, adjusting for Y3 covariates (body mass index, ethnicity, and grade) and school cluster. Results support the value of team sports among females and resistance exercise among males as protective against changes to overweight or underweight perceptions over one year. Also, various forms of bullying victimization predicted overweight perceptions in males and females. Watching TV/movies or messaging/texting for over 2 hours/day was associated with overweight and underweight perceptions, respectively, in females only. Playing video/computer games for over 2 hours/day was associated with overweight perceptions in males and underweight perceptions in females. Findings support the potential of bullying prevention, limiting certain screen use, and supporting engagement in team sports for females and resistance exercise for males as strategies to maintain perceptions of being at “about the right weight.

Binge drinking and academic performance, engagement, aspirations, and expectations: a longitudinal analysis among secondary school students in the COMPASS study

Introduction: The longitudinal relationship between binge drinking and academic engagement, performance, and future aspirations and expectations was examined among a cohort of secondary school students. Methods: In separate multinomial generalized estimating equations models, linked data from Year 1 (Y1: 2012-2013), Year 2 (Y2: 2013-2014), and Year 3 (Y3: 2014-2015) of the COMPASS study (N = 27 112) were used to test the relative likelihood of responses to seven academic indices when binge drinking was initiated in varying frequencies, adjusting for gender, grade, race/ethnicity, tobacco use, and the individual mean of the predictor and all time-varying covariates. Results: Among students who had never engaged in binge drinking at baseline, those who reported regular binge drinking at follow-up were relatively less likely to complete their homework, attend class, and value and achieve high grades, with more frequent binge drinking at follow-up generally resulting in larger relative risk ratios. Interestingly, shifting from “never” to “rare/sporadic” binge drinking one to two years later resulted in an increased relative risk of wanting to pursue all levels of postsecondary education. Beginning binge drinking on a “monthly” basis also increased the likelihood of college/trade or bachelor degree ambitions, relative to high school, but not graduate/professional pathways; while degree aspirations were not associated with initiating weekly binge drinking. Conclusions: Results suggest students who initiate binge drinking have poor school performance and engagement, which may interfere with achieving their future academic goals. This study reinforces the reasons substance use prevention should be considered an academic priority, as such efforts may also prove beneficial for educational achievement

An analysis of weight perception and physical activity and dietary behaviours among youth in the COMPASS study

Purpose: Weight misperceptions appear common among youth, potentially influencing their motivation to engage in health-related behaviours; however, the direction of impact remains unclear. The current study examined how weight perception influences physical activity (PA) and diet among youth. Methods: This study used 2-year linked data of 19,322 grade 9–12 students from Year 2 (Y2:2013-2014) and 3 (Y3:2014-2015) of the COMPASS study. Generalized Estimating Equation models tested the effect of Y3 weight perception on the various Y3 PA and dietary behaviour measures, adjusting for Y3 covariates (grade, race/ethnicity, weekly spending money), school cluster, school area median household income, and the Y2 outcome. Models were stratified by gender and body mass index (BMI) classification. Results: Regardless of BMI status, overweight perceptions among boys and girls were associated with lower likelihoods of playing school sports, physical education class enrollment, meeting resistance exercise recommendations, eating breakfast regularly, and less vigorous-intensity PA, and among boys only, lower odds of meeting PA guidelines, compared to their peers who perceived their weight as “about right”. In boys with normal-weight BMIs, underweight perceptions predicted less vigorous-intensity PA, and lower odds of physical education class enrollment, and of meeting PA and resistance exercise recommendations, than “about right” perceptions. Among girls, underweight perceptions predicted lower likelihoods of engaging in adequate resistance exercise and playing intramurals, and greater odds of eating fast food on weekends, purchasing snacks, and drinking energy drinks and sugar-sweetened beverages. Girls with overweight/obese BMIs who perceived their weight as such were less likely to consume adequate fruits and vegetables relative to their counterparts with “about right” weight perceptions. Conclusions: Overall, weight perceptions of “about right” appear more favourable for health behaviours among youth across the weight range. Results suggest obesity prevention strategies aiming to increase awareness of weight status may have unintended effects. Keywords: Weight perception, Physical activity, Diet, Nutrition, Obesity, Body image, Yout