Karen A. Patte

Dopamine Transporter Gene (DAT1) Associated with Appetite Suppression to Methylphenidate in a Case-Control Study of Binge Eating Disorder

Response to psychomotor stimulants is highly variable across individuals. Such inconsistencies are influenced by many factors including drug dose and polymorphic differences in genes that encode proteins, such as the dopamine transporter (DAT1), which are relevant to the site of action of these substances. The current study used a double blind, crossover (methylphenidate vs placebo) design to assess DAT1 genotype differences on appetite ratings to a snack-food cue in subjects with binge eating disorder (BED) (n=32) and healthy age-matched controls (n=46). ANOVA results indicated a significant genotype × diagnostic group interaction whereby BED subjects with at least one copy of the 9-repeat allele showed a significant suppression of appetite in response to methylphenidate compared with controls with this allele, or to subjects with the 10/10 genotype (irrespective of diagnosis) whose drug response was indistinguishable from placebo. The most probable explanation for these findings is that some, currently unknown, genetic variant, which is overrepresented in those with BED, interacts with DAT1 to suppress appetite in response to stimulant administration. The current findings have implications for treatment response to drugs currently in use (or being developed) for the treatment of overeating and overweight.

A Behavioral Genetic Model of the Mechanisms Underlying the Link Between Obesity and Symptoms of ADHD

Objective: The ADHD–obesity link has been suggested to result from a shared underlying basis of suboptimal dopamine (DA); however, this theory conflicts evidence that an amplified DA signal increases the risk for overeating and weight gain. A model was tested in which ADHD symptoms, predicted by hypodopaminergic functioning in the prefrontal cortex, in combination with an enhanced appetitive drive, predict hedonic eating and, in turn, higher body mass index (BMI). Method: DRD2 and DRD4 markers were genotyped. The model was tested using structural equation modeling in a nonclinical sample (N = 421 adults). Results: The model was a good fit to the data. Controlling for education, all parameter estimates were significant, except for the DRD4-ADHD symptom pathway. The significant indirect effect indicates that overeating mediated the ADHD symptoms–BMI association. Conclusion: Results support the hypothesis that overeating and elevated DA in the ventral striatum—representative of a greater reward response—contribute to the ADHD symptom–obesity relationship.

Youth sleep durations and school start times: a cross-sectional analysis of the COMPASS study

Objectives: This study explored school start times (SST) in relation to sleep duration and adherence to guidelines among Canadian youth. Methods: Using Year 4 (2015/2016) data from the Cannabis, Obesity, Mental health, Physical activity, Alcohol use, Smoking, and Sedentary behaviour (COMPASS) study, the sample included 35,821 grade 9‐12 students at 78 secondary schools in Ontario and Alberta, Canada. Random intercepts models tested student‐reported sleep duration and whether students met sleep recommendations, as a function of SST, controlling for student‐ (race/ethnicity, grade, sex, travel mode to school) and school‐level (school‐area urbanicity and median household income) correlates. Results: For each hour delay in SST, students reported an average of almost 7 minutes longer sleep and had 1.17 (adjusted odds ratio; 95% confidence interval, 1.04‐1.31) higher odds of meeting the recommendations, with other factors held constant. Conclusions: Potential impacts on student sleep require consideration when deciding on school schedules. Delayed SST warrant further exploration as an intervention to help ameliorate the widespread sleep deprivation found among Canadian youth.

Marijuana and Alcohol Use as Predictors of Academic Achievement: A Longitudinal Analysis among Youth in the COMPASS Study.

BACKGROUND We tested the effect of initiating marijuana and alcohol use at varying frequencies on academic indices. METHODS In a sample of 26,475 grade 9-12 students with at least 2 years of linked longitudinal data from year 1 (Y1: 2012-2013), year 2 (Y2: 2013-2014), and year 3 (Y3: 2014-2015) of the COMPASS study, separate multinomial generalized estimating equations models tested the likelihood of responses to measures of academic goals, engagement, preparedness, and performance when shifting from never using alcohol or marijuana at baseline to using them at varying frequencies at follow -up. RESULTS Students who began using alcohol or marijuana were less likely to attend class regularly, complete their homework, achieve high marks, and value good grades, relative to their abstaining peers. Changing from abstaining to rare/sporadic-to-weekly drinking or rare/sporadic marijuana use predicted aspirations to continue to all levels of higher education, and initiating weekly marijuana use increased the likelihood of college ambitions, while more regular marijuana use reduced the likelihood of wanting to pursue graduate/professional degrees, over high school. CONCLUSIONS The importance of delaying or preventing substance use is evident in associations with student performance and engagement. The influence on academic goals varied by substance and frequency of initiated use.

A cross-sectional analysis examining the association between dieting behaviours and alcohol use among secondary school students in the COMPASS study

Background Unhealthy weight-control methods and problematic alcohol use appear linked, with individuals engaging in both behaviours at greater risk of adverse consequences. Most studies have been conducted among females and young adults, yet both dieting and binge drinking emerge at earlier stages of development. Moreover, gender differences are likely due to contrasting body ideals. This study investigated the co-occurrence of dieting and alcohol use among youth, focusing on varying weight goals in males and females, and meal skipping, as a form of food restriction. Methods Cross-sectional analyses were conducted in sample of 44 861 Grade 9-12 students from Year 2 (2013-14) of the COMPASS study. Results and conclusions The majority of females were trying to lose weight, while males tended to report efforts to gain and these two groups demonstrated the highest odds of alcohol use and binge drinking. Breakfast and lunch skipping predicted binge drinking and alcohol use in females, but only the former was related to drinking behaviour in males. Breakfast skipping rarely occurred for weight loss purposes, although more females reported this reason for missing meals than males. Results support hypothesized gender variations in weight goals and meal skipping, and differing associations with drinking behaviour.

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.

Sleep duration trends and trajectories among youth in the COMPASS study

Objectives: Limited Canadian studies have examined youth sleep over time. This study explored sleep duration over recent years among youth, patterns over the course of secondary school, and subgroups at greater risk of sleep deprivation and problematic trajectories. Design: Longitudinal survey. Participants/Setting: Secondary school students in Ontario and Alberta, Canada. Measures and analyses: In cross‐sectional analyses, student‐reported sleep duration was analyzed in three waves of the COMPASS study (Y2: 2013/2014, Y3: 2014/2015, Y4: 2015/2016), and differences by student‐level (race/ethnicity, grade, sex) and school‐level (urbanicity, median household income) variables were tested in the most recent wave. For the longitudinal analyses, group‐based trajectory modeling was conducted using 3‐year linked data, adding risk factors as predictors of problematic trajectories. Results: Average sleep durations declined over the 3 study waves, resulting in less than half of youth meeting the guideline of 8‐10 hours per night. Four trajectory groups comprised almost 90% of participants, with 8.8% of students classified as long sleepers, whereas more than one‐third of students belonged to 2 sleep‐deprived trajectory groups (short [9.3%] and low‐normal [26.7%]). In both the cross‐sectional and longitudinal analyses, longer sleep durations were more likely among students who identified as male, White, in earlier grades, and attending schools in areas with higher median household income and classified as rural/small urban, relative to their counterparts. Conclusions: Results support the necessity of continued surveillance and interventions to monitor and counteract what appears to be an ongoing trend of diminishing sleep and a growing number of sleep‐deprived adolescents. Targeted efforts in less affluent and more metropolitan areas warrant consideration.

Is Binge Drinking Onset Timing Related to Academic Performance, Engagement, and Aspirations Among Youth in the COMPASS Study?

ABSTRACT Background: Some evidence suggests early initiation of alcohol use is associated with academic underachievement; however, substance use onset is an ambiguous concept, resulting in mixed findings across studies. Moreover, the quantity of early use is likely an important determinant. Binge drinking is a common pattern among younger cohorts, and is shown to magnify the risk of related problems. Objectives: The current study explored how students who initiated binge drinking early (grade 10 or earlier) or later in high school (grade 11 or 12) differed in relation to a variety of academic indices. Methods: The sample consisted of 19,764 grade 9 to 12 students with at least 2 years of linked-longitudinal data from Year 1(Y1: 2012-2013), Year 2(Y2: 2013-2014), and Year 3(Y3: 2014-2015) of the COMPASS study. Separate multinomial GEE models tested the likelihood of different responses to outcome measures of academic goals, engagement, preparedness, and performance based on the timing of binge drinking onset. Models adjusted for binge drinking initiation in varying frequencies, gender, grade, race/ethnicity, and smoking. Results: Compared to students with earlier onsets of binge drinking, youth with later onsets were more likely to regularly attend class, complete their homework, value good grades, achieve high English or Math marks, have graduate/professional degree ambitions, and expect to obtain a college/trade school diploma after high school, yet they were less likely to expect to achieve a bachelors degree. Conclusion: Results highlight the importance of substance use prevention programs targeting early adolescents. Both delaying and preventing binge drinking have the potential to improve scholastic outcomes.

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

AIMS The objective of the study was to examine if depression or anxiety was associated with youth cannabis use; and investigate whether flourishing, an indicator of overall wellbeing, moderates these associations. METHODS Students (N=6550) 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 [Deiners Flourishing Scale], and cannabis 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, 32% of participants had ever used cannabis, and 42% and 32% 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 (all interactions were not statistically significant). Instead, robust associations were found between flourishing and cannabis use (ever use and 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.

Modifiable predictors of insufficient sleep durations: A longitudinal analysis of youth in the COMPASS study

The purpose of the current study was to simultaneously examine commonly proposed risk and protective factors for sleep deprivation over time among a large cohort of Ontario and Alberta secondary school students. Using 4-year linked longitudinal data from youth in years 1 through 4 (Y1[2012/2013], Y2[2013/2014], Y3[2014/2015], Y4[2015/2016]) of the COMPASS study (n=26,205), the likelihood of students meeting contemporary sleep recommendations was tested based on their self-reported substance use, bullying victimization, physical activity, and homework and screen time. Models controlled for the effect of student-reported gender, race/ethnicity, grade, school clustering, and all other predictor variables. Relative to baseline, students became less likely to meet the sleep recommendations if at follow-up they had initiated binge drinking, experienced cyber bullying victimization, or were spending more time doing homework, with other factors held constant. The likelihood of reporting sufficient sleep increased if students had begun engaging in resistance training at least three times a week. No longitudinal effect was observed when students increased their caffeine consumption (energy drinks, coffee/tea), initiated cannabis or tobacco use, experienced other forms of bullying victimization (physical, verbal, or belongings), engaged in more moderate-vigorous physical activity, or increased their screen use of any type. Few of the commonly purported modifiable risk and protective factors for youth sleep deprivation held in multinomial longitudinal analyses. Causal conclusions appear premature, with further research required to confirm the targets likely to be most effective in assisting more youth in meeting the sleep recommendations.