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Background: Movement behaviors (i.e., physical activity [PA], sedentary behaviors [SB], sleep) relate to mental health. Although movement behaviors are often analyzed as distinct entities, they are in fact highly inter‐dependent (e.g., if an individual increases sleep, then PA and/or SB must be reduced) and these dependencies should be accounted for in the analysis. We tested whether perceptions of time spent in movement behaviors (i.e., moderate‐to‐vigorous intensity PA [MVPA], light physical activity [LPA], SB, and sleep) related to depressive symptoms and self‐report mental health in young adults using a compositional analysis. We then estimated change in depressive symptoms with reallocation of time across movement behaviors using compositional time‐reallocation models. Methods: Data were drawn from the longitudinal NDIT dataset. Complete data were available for 770 young adults (Mage = 20.3, 55% females). Results: The proportion of time spent in MVPA relative to other movement behaviors related to depressive symptoms non‐significantly and to mental health significantly. Reallocating 15 min from MVPA to SB resulted in a significant (0.46 unit) increase in depressive symptoms, and reallocating 15 min of MVPA to LPA was associated with a (0.57) increase in depressive symptoms. Conclusion: These results indicate the importance of relative time spent in each movement behavior to mental health. Further research should examine these associations over time. [ABSTRACT FROM AUTHOR]

Introduction: We examined the mediating role of friends smoking in the association between depressive symptoms and daily/weekly cigarette smoking from adolescence into adulthood.Methods: Data were drawn from the Nicotine Dependence In Teens study (NDIT, Canada) and the Avon Longitudinal Study of Parents and Children (ALSPAC, UK) studies. Three age groups were investigated in NDIT: age 13-14 (n = 1189), 15-16 (n = 1107), and 17-18 (n = 1075), and one in ALSPAC (n = 4482, age 18-21). Multivariable mediation models decomposed the total effect (TE) of depressive symptoms on smoking into a natural direct effect (NDE) and natural indirect effect (NIE) through friends smoking.Results: The odds ratios (ORs) for the TE were relatively constant over time with estimates ranging from 1.12 to 1.35. Friends smoking mediated the association between depressive symptoms and smoking in the two youngest samples (OR [95% confidence interval [CI] 1.09 [1.01,1.17] in 13- to 14-year-olds; 1.10 [1.03,1.18] in 15- to 16-year-olds). In the two older samples, NDE of depressive symptoms was close to the TE, suggestive that mediation was absent or too small to detect.Conclusion: Friends smoking mediates the association between depressive symptoms and daily/weekly cigarette smoking in young adolescents.Implications: If young adolescents use cigarettes to self-medicate depressive symptoms, then interventions targeting smoking that ignore depressive symptoms may be ineffective. Our results also underscore the importance of the influence of friends in younger adolescents, suggestive that preventive intervention should target the social environment, including social relationships. [ABSTRACT FROM AUTHOR]

Copyright of Applied Physiology, Nutrition & Metabolism is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Physical activity levels decline from adolescence to adulthood, but participation in a variety of sports during childhood and adolescence (i.e., sampling) may increase physical activity behaviour during adulthood. We examined the association between sampling sports during adolescence and moderate-vigorous exercise behaviour in adulthood, and we assessed whether this relationship is mediated by perceived variety in exercise. Design: Study 1- prospective longitudinal; Study 2- cross-sectional. Our main outcome was exercise behaviour. Results: In study 1 (n = 775), sampling more sports during adolescence (b =.25, p <.01; 95% CI [.12,.39]) predicted increased frequency of exercise behaviour in young adulthood. In study 2 (n = 108), sampling more sports in adolescence (β =.08, p =.03; 95% CI [.03,.17]) was indirectly associated with exercise behaviour in adulthood through perceived variety in exercise. Conclusion: These findings add to the evidence that sampling sports during adolescence is positively associated with moderate-vigorous exercise during adulthood, and the experience of variety may, in part, explain this relationship. This research generates new hypotheses regarding a potential psycho-social mediator (perceived variety in exercise) of the sampling-exercise behaviour relationship. [ABSTRACT FROM AUTHOR]

Background: Despite the benefits of physical activity, many Canadian adolescents are inactive and rates of inactivity increase with age. Few studies describe the pattern of change in physical activity as a function of age during adolescence. Methods: Data were drawn from the Nicotine Dependence in Teens Study. The analytic sample included 1206 adolescents who completed a 7-day physical activity recall up to 4 times per year over 5 years. Individual growth models, analyzed using multilevel models for change, were developed separately by sex controlling for season. Results: Physical activity levels through adolescence were best described by a cubic function. Levels increased from age 12 to a peak at approximately age 13.5, decreased to age 16.5, and increased again to age 17. Activity participation was highest in the spring and lowest during fall and winter. Substantial within- and between-subject heterogeneity in the trajectories was evident. Conclusion: Adolescent physical activity follows a complex, curvilinear pattern in both males and females, with considerable variation within- and between-persons. [ABSTRACT FROM AUTHOR]

Despite limited evidence on the association between physical activity (PA) and blood pressure (BP) in youth, experts recommend that adolescents engage regularly in moderate-to-vigorous PA. We examined the relationships between PA intensity and frequency and the likelihood of having high BP in a population-based cohort of adolescents from Montréal, Canada. PA was self-reported every 3 months from grade 7 to 11, and BP was measured at ages 12.8, 15.2, and 17.0 years on average. We analyzed data from 993 participants (mean [SD] age = 16.0 [1.0], 51.6% female) with BP data at ages 15.2 and/or 17.0 years, using pooled ordinal logistic regression. BP (normal/elevated/hypertensive range) was the outcome, and past-year PA intensity and frequency were potential predictors. Eight percent of participants had elevated BP (120-129/<80), and 3.2% had BP in the hypertensive range (≥130/≥80). Participants engaged in a median (interquartile range) of 7.0 (4.5, 9.3) and 5.5 (2, 10.8) moderate and vigorous PA sessions/week, respectively. After adjusting for age, sex, mother's education, use of alcohol and cigarette consumption, engaging in PA more intense than light during the previous year was associated with a lower odds of having BP in the hypertensive range (ORs [95% CIs] = 0.93 [0.88, 0.97] to 0.97 [0.94, 0.99]). The relationships were not altered by adjusting for BMI. Our findings support recommendations that adolescents engage in at least moderate PA on a regular basis to prevent development of BP in the hypertensive range. [ABSTRACT FROM AUTHOR]

Background: Physical activity (PA) can promote mental health, but the mechanisms underpinning this association are not well-established. This study examined if perceptions of three basic psychological needs (autonomy, competence, relatedness) and moderate-to-vigorous physical activity (MVPA) mediate the association between number of years participating in PA and mental health in adolescence. Methods: Participants included 937 children (55% female) age 10–11 at inception of the longitudinal MATCH study, who provided data every 4 months over 6 years. Mediation analyses were used to assess the natural direct effect of number of years of PA participation (cycles 1–15) during late childhood and adolescence on later mental health (cycle 16), measured with the Mental Health Continuum-Short Form (MHC-SF), and the natural indirect effect through each of self-perceived autonomy, competence and relatedness, and self-report MVPA (cycle 15). Results: In single mediator models, indirect effects of autonomy, competence, relatedness and self-report MVPA were statistically significant. In joint mediation models (each of three models including one basic psychological need and MVPA), autonomy, competence and relatedness mediated 71, 27, and 51% of the association respectively; MVPA mediated 27–31% of the association. In the mediation model including all four mediators, relatedness mediated the largest proportion of the association, followed by autonomy and MVPA. Conclusion: Results support developing strategies to encourage adolescents to engage and remain involved in PA. This could foster perceptions of autonomy, competence, and relatedness as well as MVPA, which in turn may enhance mental health. [ABSTRACT FROM AUTHOR]

Introduction: We investigated whether secondhand smoke (SHS) exposure is associated with depressive symptoms in a population-based sample of children.Methods: Never-smoking students from 29 French-language elementary schools in Greater Montréal, Canada, were followed from 5th to 11th grade (2005-2011) in five waves: 1 (5th grade), 2 (spring 6th grade), 3 (7th grade), 4 (9th grade), and 5 (11th grade). Associations between depressive symptoms and SHS exposure at home and in cars were examined in cross-sectional and longitudinal gamma generalized regression models adjusted for sex, maternal education, and neighborhood socioeconomic status.Results: The sample comprised 1553 baseline never-smokers (mean [SD] age = 10.7 [0.5] years; 44% male; 89% French-speaking). SHS exposure at home and in cars was associated with higher depressive symptom scores in cross-sectional analyses pooled across grades and adjusted for demographics (B [95% confidence interval (CI)] = 0.041 [0.017 to 0.068] for home exposure; 0.057 [0.030 to 0.084] for car exposure). In longitudinal analyses from fifth to sixth grade, B (95% CI), adjusted for demographics and baseline depressive symptoms, was 0.042 (0.003 to 0.080) for home exposure and 0.061 (0.019 to 0.103) for car exposure. From sixth to seventh grade, B (95% CI) was 0.057 (0.003 to 0.110) for home exposure and 0.074 (0.015 to 0.133) for car exposure. SHS exposure at any age did not predict depressive symptoms 2 years later.Conclusions: SHS exposure is associated with depressive symptoms in young persons, both concurrently and 1 year later. This finding adds to the evidence base supporting that children should be protected from SHS exposure.Implications: SHS exposure has deleterious effects on physical health and results of this study raise concerns that such exposure might also affect the mental health of young persons. Clearly, protecting children from SHS in all locations is a critical public health priority. Although research is needed to determine if the association between SHS exposure and depressive symptoms is causal, continued implementation of smoking bans and educational efforts to discourage smoking in vehicles when children are present are warranted. [ABSTRACT FROM AUTHOR]

The Nicotine Dependence in Teens (NDIT) study is a prospective cohort investigation of 1294 students recruited in 1999-2000 from all grade 7 classes in a convenience sample of 10 high schools in Montreal, Canada. Its primary objectives were to study the natural course and determinants of cigarette smoking and nicotine dependence in novice smokers. The main source of data was self-report questionnaires administered in class at school every 3 months from grade 7 to grade 11 (1999-2005), for a total of 20 survey cycles during high school education. Questionnaires were also completed after graduation from high school in 2007-08 and 2011-12 (survey cycles 21 and 22, respectively) when participants were aged 20 and 24 years on average, respectively. In addition to its primary objectives, NDIT has embedded studies on obesity, blood pressure, physical activity, team sports, sedentary behaviour, diet, genetics, alcohol use, use of illicit drugs, second-hand smoke, gambling, sleep and mental health. Results to date are described in 58 publications, 20 manuscripts in preparation, 13 MSc and PhD theses and 111 conference presentations. Access to NDIT data is open to university-appointed or affiliated investigators and to masters, doctoral and postdoctoral students, through their primary supervisor (www.nditstudy.ca). [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Psychiatry is the property of Sage Publications Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Adolescent physical activity (PA) levels track into adulthood. However it is not known if type of PA participated in during adolescence is associated with PA levels later in life. We aimed to identify natural groupings of types of PA and to assess whether number of years participating in these different groupings during adolescence is related to PA level in early adulthood. Methods: 673 adolescents in Montreal, Canada, age 12-13 years at baseline (54 % female), reported participation in 29 physical activities every 3 months over 5 years (1999-2005). They also reported their PA level at age 24 years (2011-12). PA groupings among the 29 physical activities were identified using factor analysis. The association between number of years participating in each grouping during adolescence and PA level at age 24 was estimated using linear regression within a general estimating equation framework. Results: Three PA groupings were identified: "sports", "fitness and dance", and "running". There was a positive linear relationship between number of years participating in sports and running in adolescence and PA level at age 24 years (β (95 % confidence interval) = 0.09 (0.04-0.15); 0.08 (0.01-0.15), respectively). There was no relationship between fitness and dance in adolescence and PA level at age 24. Conclusions: The association between PA participation in adolescence and PA levels in young adulthood may be specific to certain PA types and to consistency of participation during adolescence. Results suggest that efforts to establish the habit of participation in sports and running in adolescence may promote higher PA levels in adulthood. [ABSTRACT FROM AUTHOR]

Background Binge drinking occurs frequently among young adults, posing risks to health and safety. Little is known, however, about which drinkers continue to binge later into adulthood. We sought to identify predictors of sustained binge drinking behaviors in young adulthood. Methods Participants from the Nicotine Dependence in Teens ( NDIT) cohort ( n = 609, 53% female) completed self-report questionnaires in 20 survey cycles ( SCs) during secondary school between 1999 and 2005, and in 2 postsecondary school SCs in 2007 to 2008 ( SC 21; Mage = 20 years) and 2011 to 2012 ( SC 22; Mage = 24 years). Participants reporting past-year binge drinking in both SCs 21 and 22 were categorized as sustainers ( n = 517). Using multivariable logistic regression, we investigated 25 potential predictors of sustained binge drinking, binge-drinking frequency, and change in frequency over time among sustainers. Results Compared with stoppers, sustainers (85% of participants) were more likely to be younger, male, and to have no college/university education. Sustainers began drinking alcohol and binge drinking earlier, drank at least monthly during more secondary school grades, binged more frequently at age 20, and scored higher on impulsivity and novelty seeking in adolescence. Among sustainers, frequent binge drinkers were more likely to be male, to be nonstudents, to score higher on novelty seeking, and to have reported more depressive symptoms in adolescence. Sustainers who decelerated their binge frequency between SCs 21 and 22 were more likely to be female, to have achieved a higher level of education, and to report more depressive symptoms in SC 21. Conclusions The determinants of sustained binge drinking are similar to predictors of binge drinking reported in the literature. Early identification of, and intervention with, youth who are impulsive, inclined toward novelty seeking, and who report higher levels of early sub clinical depressive symptoms might forestall their involvement in risky alcohol use. [ABSTRACT FROM AUTHOR]

Identifying food patterns related to obesity can provide information for health promotion in nutrition. Food patterns and their relation with obesity among Canadian children have not been reported to date. Our aim was to identify and describe food patterns associated with obesity in children at risk of overweight. Caucasian children ( n = 630) with at least 1 obese biological parent recruited into the Quebec Adiposity and Lifestyle Investigation in Youth (QUALITY) cohort were studied in cross-sectional analyses. Measures of adiposity (body mass index (BMI), waist circumference, body fat mass percentage measured by dual-energy X-ray absorptiometry), screen time, physical activity (accelerometer over 7 days), and dietary intake (three 24-h food recalls) were collected. Factor analysis was used to identify food patterns. The relationships between food patterns and overweight were investigated in logistic and multiple linear regression models. Three food patterns were retained for analysis: traditional food (red meats, main dishes-soups, high-fat dairy products, tomato products, dressings, etc.); healthy food (low-fat dairy products, whole grains, legumes-nuts-seeds, fruits, vegetables); and fast food (sugar-sweetened beverages, fried potatoes, fried chicken, hamburgers-hot dogs-pizza, salty snacks). Higher scores on the fast food pattern were associated with overweight (BMI ≥ 85th percentile), and other measures of adiposity (BMI, waist circumference, body fat mass percentage) after adjustment for age, sex, physical activity, screen time, sleep time, family income, and mother's obesity ( p < 0.05). Controlling for energy intake did not change these relationships. Our results provide further evidence of a link between fast food intake and obesity in children. [ABSTRACT FROM AUTHOR]

The article discusses research investigating interest of an individualized score among children using a maximal cycling test, called the OMNI cycle scale. Researchers studied the differences between perceived exertion and actual effort, measured by peak oxygen consumption, at various stages of the test to determine whether perceived exertion and actual effort differed according to body mass status or physical activity level. The study's experimental design and methodology, a discussion of the results, and researchers' conclusions regarding the relationship between the effort performed, the OMNI cycle scale score, body mass status, and physical activity level are presented.

Objective: To measure the construct validity of the Night Eating Questionnaire (NEQ) in children against a parent report of child night eating syndrome (NES) symptoms (NEQ report) and a 3-day dietary recall. Method: NEQ of 304 children from the QUALITY (QUébec Adipose and Lifestyle InvesTigation in Youth) cohort were compared to a parent report and 3-day dietary recall. Results: Child NEQ scores were related to the parent NEQ report (ρ = 0.30 p < 0.0001) yet there were inconsistencies between responses concerning sleep troubles. Total child NEQ scores, but not parent NEQ report scores, were associated with dietary manifestations of NES such as increased evening (ρ = 0.20, p < .001) and reduced morning intake (ρ= −0.12, p < .05). Discussion: The NEQ score is related to eating patterns of NES in children and is more informative than a parent report, specifically when used in conjunction with dietary recall. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2012;45:861-865) [ABSTRACT FROM AUTHOR]

Objective To describe the determinants of self-initiated smoking cessation of duration of at least 6 months as identified in longitudinal population-based studies of adolescent and young adult smokers. Methods A systematic search of the PubMed and EMBASE databases using smoking, tobacco, cessation, quit and stop as keywords was performed. Limits included articles related to humans, in English, published between January 1984 and August 2010, and study population aged 10-29 years. A total of 4502 titles and 871 abstracts were reviewed independently by 2 and 3 reviewers, respectively. Nine articles were retained for data abstraction. Data on study location, timeframe, duration of follow-up, number of data collection points, sample size, age/grade of participants, number of quitters, smoking status at baseline, definition of cessation, covariates and analytic method were abstracted from each article. The number of studies that reported a statistically significant association between each determinant investigated and cessation were tabulated, from among all studies that assessed the determinant. Results Despite heterogeneity in methods across studies, five factors robustly predicted quitting across studies in which the factor was investigated: not having friends who smoke, not having intentions to smoke in the future, resisting peer pressure to smoke, being older at first use of cigarette and having negative beliefs about smoking. Conclusions The literature on longitudinal predictors of cessation in adolescent and young adult smokers is not well developed. Cessation interventions for this population will remain less than optimally effective until there is a solid evidence base on which to develop interventions. [ABSTRACT FROM AUTHOR]

BACKGROUND: The purpose of the present study was to examine whether the availability of intramural or extramural sports in secondary schools is associated with physical activity levels in youth throughout secondary school and at age 20. METHODS: Eight hundred and eight adolescents from 10 secondary schools in Montreal, Canada, provided physical activity data every 3 months during the school year from ages 13 to 17, and again at age 20. School administrators completed questionnaires on the availability of intramural and extramural sports. Three-level general linear models were used to examine associations among the number of intramural and extramural sports, moderate and vigorous physical activity controlling for age, sex, body mass index, mother’s education, and school-level socioeconomic status. RESULTS: Regardless of whether or not they reported participating in intramural sports, adolescents in schools with more intramural sports engaged in 3.6 (p = .03) more total, and 1.3 (p = 0.03) more vigorous activities per week than those attending schools with fewer intramural sports. Number of extramural sports was not statistically significantly associated with physical activity, regardless of whether or not individual students participated. CONCLUSION: Providing more opportunities for intramural sports in secondary schools may be an effective strategy to help adolescents attain physical activity recommendations. [ABSTRACT FROM AUTHOR]

Objectives. We sought to document the sequence and timing of milestones in the process of smoking cessation by prospectively studied cessation milestones among novice adolescent smokers. Methods. Participants, aged 12 to 13 years in 1999 (n=1293), completed self-report questionnaires every 3 months during the school year over 5 years. We ascertained time after first puff to attain 5 cessation milestones among 319 participants who initiated cigarette smoking during follow-up. Results. The cumulative probability of first reports of a serious desire to quit and perceived permanent cessation was 25% at 1.5 months (95% confidence interval [CI]=1.5, 2.5) after the first puff. The first serious quit attempt occurred at 2.5 months (95% C1=2.5, 5.4), lack of confidence about quitting followed at 18.4 months (95% CI=18.4, 26.8), and awareness of the difficulty of quitting occurred at 32.2 months (95% CI=19.2, 38.4). Conclusions. Desire and attempts to quit began soon after smoking onset. Novice smokers progressed through several stages in their perception of the difficulty of quitting. Increased understanding of the cessation process may help in developing effective tobacco control interventions for novice smokers. [ABSTRACT FROM AUTHOR]

Background: Obesity in North America is now endemic, and increased understanding of the determinants of physical inactivity is critical. This analysis identified predictors of declines in physical activity over 5 years among adults in low-income, inner-city neighbourhoods. Methods: Data on leisure time physical activity were collected in telephone interviews in 1992 and 1997 from 765 adults (47% of baseline respondents), as part of the evaluation of a community-based cardiovascular disease risk reduction program. Results: One-third of 527 participants who were physically active at baseline, were inactive in 1997. Predictors of becoming inactive included female sex (OR = 1.63 95% CI (1.09, 2.43)), older age (1.02 (1.01, 1.04)), higher BMI (1.57 (1.03, 2.40)), poor self-rated health (1.39 (1.05, 1.84)), lower self-efficacy for physical activity (1.46 (1.00, 2.14)), and not using a neighborhood facility for physical activity (1.61 (1.02, 2.14)). Conclusion: These results highlight the fact that a variety of variables play a role in determining activity level, from demographic variables such as age and sex, to psychosocial and environmental variables. In addition, these results highlight the important role that other health-related variables may play in predicting physical activity level, in particular the observed association between baseline BMI and the increased risk of becoming inactive over time. Lastly, these results demonstrate the need for multi-component interventions in low-income communities, which target a range of issues, from psychosocial factors, to features of the physical environment. [ABSTRACT FROM AUTHOR]

Longitudinal studies are needed to increase understanding of the causes of childhood obesity. To identify 1- and 2-year predictors of excess weight gain among preadolescents, the authors conducted a prospective cohort study of fourth- and fifth-grade students in 16 elementary schools located in multiethnic, low-income neighborhoods in Montreal, Quebec, Canada, that were participating in the evaluation of a school-based heart health promotion program. Subjects included 2,318 children aged 9–12 years with baseline and 1-year follow-up data and 633 children aged 9–11 years with baseline and 2-year follow-up data. One-year predictors of highest decile of change in body mass index (BMI) identified in logistic regression analyses included baseline BMI of 90th percentile or more (odds ratio (OR) = 2.66, 95% confidence interval: 1.80, 3.94) in boys and baseline BMI of 90th percentile or more (OR = 2.34, 95% confidence interval: 1.46, 3.76), no sports outside school (OR = 1.90, 95% confidence interval: 1.18, 3.06), and playing video games everyday (OR = 2.48, 95% confidence interval: 1.04, 5.92) in girls. Two-year predictors included baseline BMI of 90th percentile or more (OR = 3.26, 95% confidence interval: 1.52, 7.01), no sports outside school (OR = 2.14, 95% confidence interval: 0.96, 4.77), and least active (OR = 2.18, 95% confidence interval: 1.01, 4.71) in boys; only baseline BMI of 90th percentile or more (OR = 2.22, 95% confidence interval: 1.02, 4.81) was significant in girls. Results suggest the need for interventions to promote increased physical activity in children. Am J Epidemiol 2000;152:739–46. [ABSTRACT FROM PUBLISHER]

This study describes student perceptions of school staff smoking before and after implementation of legislation prohibiting smoking on school grounds. Students completed self-report questionnaires before (grade 6) and after (grade 7, 9 and 11) the law. The percentage of students reporting that school staff smoked in areas where smoking is forbidden was 19%, 32% and 33% in grade 7, 9 and 11, respectively. The mean(SD) score for the frequency with which students saw school staff smoking decreased after the ban but increased thereafter [2.5(1.1), 1.9(1.0), 2.4(1.1) and 2.3(1.1)] in grade 6, 7, 9 and 11, respectively [F(2.861,1662.229) = 45.350, P < 0.001]. These data suggest that the effect of the law dissipated over time. [ABSTRACT FROM AUTHOR]

Context: The onset of cigarette smoking typically occurs during childhood or early adolescence. Nicotine dependence symptoms can manifest soon after onset, contributing to sustained, long-term smoking. Previous reviews have not clarified the determinants of onset.Evidence Acquisition: In 2015, a systematic review of the literature in PubMed and EMBASE was undertaken to identify peer-reviewed prospective longitudinal studies published between January 1984 and August 2015 that investigated predictors of cigarette smoking onset among youth aged <18 years who had never smoked.Evidence Synthesis: Ninety-eight conceptually different potential predictors were identified in 53 studies. An increased risk of smoking onset was consistently (i.e., in four or more studies) associated with increased age/grade, lower SES, poor academic performance, sensation seeking or rebelliousness, intention to smoke in the future, receptivity to tobacco promotion efforts, susceptibility to smoking, family members' smoking, having friends who smoke, and exposure to films, whereas higher self-esteem and high parental monitoring/supervision of the child appeared to protect against smoking onset. Methodologic weaknesses were identified in numerous studies, including failure to account for attrition or for clustering in samples, and misidentification of potential confounders, which may have led to biased estimates of associations.Conclusions: Predictors of smoking onset for which there is robust evidence should be considered in the design of interventions to prevent first puff in order to optimize their effectiveness. Future research should seek to define onset clearly as the transition from never use to first use (e.g., first few puffs). [ABSTRACT FROM AUTHOR]

Background: Smoking is influenced by genetic factors including variation in CYP2A6 and CYP2B6, which encode nicotine-metabolizing enzymes. In early adolescence, CYP2A6 slow nicotine metabolism was associated with higher dependence acquisition, but reduced cigarette consumption. Here we extend this work by examining associations of CYP2A6 and CYP2B6 with tobacco dependence acquisition in a larger sample of smokers followed throughout adolescence.Methods: White participants from the Nicotine Dependence in Teens cohort that had ever inhaled (n=421) were followed frequently from age 12-18 years. Cox's proportional hazards models compared the risk of ICD-10 tobacco dependence acquisition (score 3+) for CYP2A6 and CYP2B6 metabolism groups. Early smoking experiences, as well as amount smoked at end of follow-up, was also computed. At age 24 (N=162), we assessed concordance between self-reported cigarette consumption and salivary cotinine.Results: In those who initiated inhalation during follow-up, CYP2A6 slow (vs. normal) metabolizers were at greater risk of dependence (hazards ratio (HR)=2.3; 95% CI=1.1, 4.8); CYP2B6 slow (vs. normal) metabolizers had non-significantly greater risk (HR=1.5; 95% CI=0.8, 2.6). Variation in CYP2A6 or CYP2B6 was not significantly associated with early smoking symptoms or cigarette consumption at end of follow-up. At age 24, neither gene was significantly associated with dependence status. Self-reported consumption was associated with salivary cotinine, a biomarker of tobacco exposure, acquired at age 24 (B=0.37; P<0.001).Conclusions: Our findings extend previous work indicating that slow nicotine metabolism mediated by CYP2A6, and perhaps CYP2B6, increases risk for tobacco dependence throughout adolescence. [ABSTRACT FROM AUTHOR]

Abstract: Smoking to alleviate negative affect or improve physiological functioning (i.e., self-medication) is one explanation for the association between depression and smoking in adolescents. This study tests whether using cigarettes to improve mood or physiological functioning is associated with the onset, and change over time, of elevated depressive symptoms. Data were drawn from the Nicotine Dependence in Teens study which followed 1293 participants initially aged 12–13years in Montreal, Canada every three months for five years. The subsample included 662 adolescents who had been current smokers (reported smoking during the previous three months) at any point during the study. Survival analysis was used to test whether self-medication scores predicted onset of elevated depressive symptoms. Changes over time in depressive symptom scores relative to self-medication scores were modeled in growth curve analyses controlling for sex and number of cigarettes smoked per week. Smokers who reported higher self-medication scores had higher depressive symptom scores. The interaction between self-medication scores and the acceleration rate in depressive symptom scores was significant and negative, suggesting that participants with higher self-medication scores had decelerated rates of change in depression over time compared to participants with lower self-medication scores. Smoking appears to be ineffective at reducing depressive symptoms. These findings are consistent with a version of the Positive Resource Model that suggests that smoking will not lower depressive symptoms, but could slow the rate of change over time. Alternatively, the perceived positive benefits may be the result of alleviation of symptoms of withdrawal and craving resulting from abstinence. The self-medication scale may identify a population at risk of increased levels of depressive symptoms. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To describe the development of a prognostic tool to identify adolescents at risk for transitioning from never to ever smoking in the next year. METHODS: Data were drawn from the Nicotine Dependence in Teens study, a longitudinal investigation of adolescents (1999 to present). A total of 1294 students initially age 12 to 13 years were recruited from seventh-grade classes in 10 high schools in Montreal. Self-report questionnaire data were collected every 3 months during the 10-month school year over 5 years (1999-2005) until participants completed high school (n = 20 cycles). Prognostic variables for inclusion in the multivariable analyses were selected from 58 candidate predictors describing sociodemographic characteristics, smoking habits of family and friends, lifestyle factors, personality traits, and mental health. Cigarette smoking initiation was defined as taking even 1 puff on a cigarette for the first time, as measured in a 3-month recall of cigarette use completed in each cycle. RESULTS: The cumulative incidence of cigarette smoking initiation was 16.3%. Data were partitioned into a training set for model-building and a testing set to evaluate the performance of the model. The final model included 12 variables (age, 4 worry or stress- related items, 1 depression-related item, 2 self-esteem items, and 4 alcohol- or tobacco- related variables). The model yielded a c-statistic of 0.77 and had good calibration. CONCLUSIONS: This short prognostic tool, which can be incorporated into busy clinical practice, was used to accurately identify adolescents at risk for cigarette smoking initiation. [ABSTRACT FROM AUTHOR]

Purpose: We investigated whether type of physical activity (PA) (sports, running, and fitness/dance) engaged in during adolescence is associated with body composition in late adolescence or early adulthood. Methods: Data were drawn from 631 participants in the Nicotine Dependence in Teens study, a prospective investigation of students ages 12-13 yr at inception. Self-report PA data were collected at baseline, in grade 7, and every 3-4 months thereafter during the 5 yr of high school (1999-2005). Anthropometric indicators (height, weight, waist circumference, triceps, and subscapular skinfold thickness) were measured at ages 12, 16, and 24 yr. On the basis of prior exploratory factor analysis, PA was categorized into one of three types (sports, running, and fitness/dance). Regression models estimated the association between number of years participating in each PA type (0-5 yr) during high school and body composition measures in later adolescence or early adulthood. Results: In multivariable models accounting for age, sex, and parent education, more number of years participating in running during adolescence was associated with lower body mass index, waist circumference, and skinfold thickness in later adolescence and early adulthood (all P < 0.01). This association was no longer apparent in models that accounted for body composition at age 12 yr. The number of years participating in sports was positively associated with body mass index in early adulthood (P = 0.02), but fitness/dance was not statistically significantly associated with any outcome. Conclusion: Sustaining participation in running, but not in other PA types, during adolescence was related to lower body composition in later adolescence and adulthood. However, more research is needed to determine whether this association is attributable to a relationship between PA and body composition in early adolescence. [ABSTRACT FROM AUTHOR]

Abstract: Background: Recent cross-sectional studies suggest some adolescents who have never smoked cigarettes experience nicotine dependence (ND) symptoms and that exposure to second-hand smoke, social exposure to smoking, and alcohol use are plausible correlates. The aim of this study was to replicate and extend these findings by investigating possible predictors of ND symptoms longitudinally. Method: Participants included 847 secondary school students who had never smoked cigarettes enrolled in the Nicotine Dependence in Teens Study. Adolescents completed self-report questionnaires measuring smoking status, ND symptoms, and risk factors for ND in smokers (i.e., socio-demographic indicators, social exposure to smoking, psychosocial indicators, and substance use) in 20 survey cycles from 7 to 11th grade. Generalized estimating equations, which account for repeated measures within individuals, were used to test the predictors of ND symptoms. Results: Consistent with previous research, 7.8% of never-smokers across all cycles endorsed at least one ND symptom. Younger age (p ≤.001), country of birth (p ≤.05), peer smoking (p ≤.001), teacher smoking (p ≤.05), depression (p ≤.05), stress (p ≤.001), lower self-esteem (p ≤.05), impulsivity (p ≤.05), and alcohol use (p ≤.001) predicted greater ND symptoms in multivariable modeling. Conclusions: Replicating previous cross-sectional findings, peer smoking and alcohol use predicted ND symptoms among never-smoking adolescents. Extending these findings, previous predictors only observed among ever-smokers, including socio-demographic and psychosocial indicators, also predicted ND symptoms. This longitudinal investigation demonstrated the temporal relation of the predictors preceding ND symptoms. Future research should consider longer prospective studies with younger children to capture early onset of ND symptoms and with longer follow-up to detect eventual smoking uptake. [Copyright &y& Elsevier]

Abstract: Purpose: The objectives of this study were to assess (1) the longitudinal associations of past moderate-to-vigorous physical activity (MVPA) and involvement in team sports during secondary school with depressive symptoms in early adulthood, and (2) the cross-sectional associations of current MVPA and involvement in team sports with depressive symptoms during young adulthood. Methods: Data were drawn from the Nicotine Dependence in Teens study, which is an ongoing prospective cohort study of 1293 adolescents aged 12–13 years at baseline (52% female). Data analyses involved latent growth curve modeling and multiple hierarchical linear regression models. Results: Current MVPA (β = −0.12), but not past MVPA, participation was significantly negatively related to depressive symptoms during young adulthood (P < .05). Both current and past involvement in team sports were significantly negatively related to depressive symptoms (β ≥ −0.09; P < .05); however, these associations were no longer significant (P = .08) when covariates were controlled for. Conclusions: Findings provide insight about the unique associations between the timing and type of physical activity and depressive symptoms, suggesting that physical activity within team sport contexts should be encouraged so that young adults may experience less depressive symptoms. [Copyright &y& Elsevier]

OBJECTIVES: Less than 15% of children and adolescents participate regularly in physical activity (PA) and, with ever-increasing obesity, strategies to improve PA levels in youth are urgently needed. Exergaming offers a PA alternative that may be especially attractive in our increasingly technophilic society. However, there are no observational studies of exergaming in population-based samples of adolescents. The purpose of this study was to investigate potential sociodemographic, lifestyle, psychosocial, weight-related, and mental health correlates of exergaming as well as describe the type, timing, and intensity of exergaming in a population-based sample of adolescents. METHODS: Data on exergame use and potential sociodemographic, lifestyle, psychosocial, weight-related, and mental health correlates of exergaming were collected in mailed self-report questionnaires completed by 1241 grade 10 and 11 students from the Montreal area with a mean age of 16.8 years (SD = 0.05 years; 43% male) participating in the AdoQuest study. The independent correlates of exergaming were identified in multivariable logistic regression models. RESULTS: Nearly one-quarter (24%) of participants reported exergaming. Exergamers played 2 days per week on average, for ~50 minutes each bout; 73% of exergamers played at a moderate or vigorous intensity. Exergamers were more likely than nonexergamers to be girls, to play nonactive video games, to watch ≥2 hours of television per day, to be stressed about weight, and to be nonsmokers. CONCLUSIONS: Many adolescents exergame at intensity levels that could help them achieve current moderate-to-vigorous PA recommendations. Interventions that encourage exergaming may increase PA and decrease sedentary behavior in select youth subgroups, notably in girls. [ABSTRACT FROM AUTHOR]

Trajectory analyses differentiate subgroups of smokers based on early patterns of cigarette use, but no study has summarized this literature. We systematically reviewed the literature on adolescent cigarette smoking trajectories to document the number and shapes of trajectories identified, assess if certain study characteristics influence the number or shapes of trajectories identified, summarize factors associated with and outcomes of trajectory group membership, and assess whether the results of trajectory analyses help identify windows of opportunity for intervention. We searched PubMed and EMBASE (1/1/1980 to 1/11/2018) and identified 1695 articles. Forty-three articles with data from 37 unique datasets were retained. Each trajectory was categorized into one of three groups (i.e., low-stable, increasing, other). Number of trajectories ranged from 2 to 6 (mode = 4); 44-76% of participants were low-stable cigarette consumers, 11-21% increased consumption, and 3-11% were categorized as "other." Number of data points, smoking indicator used, and time axis influenced the number of trajectories identified. Only two articles depicted the natural course of smoking since onset. Factors associated with trajectory membership included age, sex/gender, race/ethnicity, parental education, behavior problems, depression, academic performance, baseline cigarette use, parental and friends smoking, alcohol use, and cannabis use. Outcomes included illicit drug and alcohol use. Beyond parsimoniously describing cigarette smoking patterns, it is not clear whether trajectory analyses offer increased insight into the natural course, determinants or outcomes of cigarette smoking in ways that inform the development of intervention. [ABSTRACT FROM AUTHOR]