[Effectiveness of a cannabis prevention program in school: results of a randomized prospective study]. / Wirksamkeit eines Cannabispräventionsprogramms in der Schule: Ergebnisse einer randomisiert-prospektiven Studie.

BACKGROUND: In the current debate about legalized access to cannabis for adults in Germany, there is widespread agreement about the need for increased prevention among children and young people. The aim of this work is to examine the effectiveness of a school-based cannabis prevention program on knowledge, attitudes, and behavior. METHOD: Cluster-randomized waiting list control group study with two study arms: "participation in the 'Der grüne Koffer' prevention program", a collection of methods for cannabis prevention, vs. "no participation" and two measurement time points before and four months after the intervention in four German states. RESULTS: The mean age of the sample of 3976 adolescents from 280 school classes in grades 8 and 9 was 14.02 years (standard deviation = 0.89). The sex ratio was balanced (49.5% female). Cannabis-related knowledge increased significantly more in the intervention group compared to the control group from the first to the second measurement time point (adjusted beta = 0.25 [95% confidence interval: 0.14-0.37]). Attitudes toward cannabis use did not change significantly in either group. In the 8th grades of the intervention group, significantly fewer adolescents (2.9%) started experimenting with cannabis use for the first time during the observation period than in the control group (5.3%), whereas no group difference was detectable in the 9th grades (interaction grade level x group: odds ratio = 2.17 [1.13-4.15], p = 0.019). DISCUSSION: The evidence of an effect of participation in the "Der grüne Koffer" prevention program on knowledge and first-time use of cannabis in the 8th grade can be considered promising against the background of previous national and international studies, which could not provide evidence of effects of school-based cannabis prevention in middle and late adolescence.

[Shaded places for skin cancer prevention in kindergartens and schools]. / Schattenplätze zur Hautkrebsprävention in Kindertagesstätten und Schulen.

BACKGROUND: Excessive UV radiation from the sun may lead to skin cancer, the most common type of cancer in Germany. Therefore, among other things, the World Health Organization recommends seeking shade during the midday hours from a UV index of 3 (3 to 5 = "moderate"). However, this important preventive measure can only be taken if sufficient shaded areas are available. The aim of the study is to record shaded areas in kindergartens and schools nationwide. METHODS: An epidemiological cross-sectional study with two samples was carried out. Management of kindergartens and schools were surveyed using online questionnaires about the provision of shading measures at their educational institution from May to August 2020 and from April to July 2021, respectively. The primary outcome was to record the presence of various structural shading measures in the outdoor area of their educational institutions. The secondary outcome was to estimate the size of the shaded exterior area. RESULTS: From the nationwide population, 1042 kindergartens (1.9%) and 713 schools (2.3%) participated. Compared to schools, kindergartens had sun protection measures in the outdoor area significantly more often (99% vs. 82%; p < 0.001) and were able to shade a significantly larger outdoor area (43% vs. 26%; p < 0.001). Assuming a minimum required shaded outdoor area of 1 m2 per person, 45% of the schools and 10% of the kindergartens did not have sufficient shaded outdoor areas (p < 0.001). CONCLUSION: Almost every fifth school in Germany had no shaded places in the outdoor area. Against the background of climatic changes, an urgent high need for improvements seems obvious.

Use of Electronic Cigarettes as a Predictor of Cannabis Experimentation: A Longitudinal Study Among German Youth.

INTRODUCTION: Experimentation with e-cigarettes is rising among youth, and there are concerns that e-cigarettes could be a new risk factor for initiating substance use. This study aimed to investigate whether e-cigarette use longitudinally predicts experimentation with cannabis. AIMS AND METHODS: During 2017-2019, a prospective cohort study with an observation period of 18 months was conducted with 3040 students from Germany who had never used cannabis (mean age = 14.8, range: 13-18 years). A multiple Poisson regression was used to investigate whether e-cigarette use was an independent predictor of future cannabis use. RESULTS: Lifetime e-cigarette use was reported by 29.4% of the survey population (n = 894) at baseline, and 17.4% (n = 529) initiated cannabis use during the observation period. Among e-cigarette ever users, the initiation rate was 34.5% compared with 10.4% of never users. Results were robust to adjustment for age, sex, migrant status, type of school, sensation seeking, peer cannabis use, the use of alcohol and conventional cigarettes (ARR = 1.83; 95% CI: 1.48-2.25). Further analyses revealed that the association between e-cigarette use and cannabis experimentation was stronger among youth with low sensation-seeking scores (ARR = .77, CI: .61-.97) and no conventional cigarette use (ARR = .48, CI: .37-.64) at baseline. CONCLUSIONS: E-cigarette use is associated with a subsequent initiation of cannabis use. This association seems to be stronger for youth who have a lower risk for substance use in general. Future studies need to investigate whether this is only true for experimental or also more frequent cannabis use. IMPLICATIONS: The study indicates a prospective association between e-cigarette use and initiation of cannabis experimentation independent of other risk factors. It suggests that e-cigarette use is more strongly associated with cannabis initiation for youth with a lower propensity to use substances (low sensation-seekers and non-smokers).

Waterpipe smoking and subsequent cigarette and e-cigarette use: a cohort study.

AIM: We tested the hypothesis that waterpipe smoking increases the likelihood to try conventional and electronic cigarettes. METHODS: In 2017 and 2018, 2752 German adolescents (mean age: 14.9 years), who had never tried conventional cigarettes or e-cigarettes, took part in a longitudinal survey with a 6-month observational period. Multiple regression analyses tested the association between waterpipe use at baseline and first experimentation with e-cigarettes at follow-up. The models adjusted for risk-taking propensity (sensation seeking and experimentation with alcohol and marijuana), age, sex, migration background, type of school and peer substance use. RESULTS: Some 381 adolescents (12.5% of the survey population) reported waterpipe smoking at baseline. The overall initiation rate during the 6 months was 4.9% (n=134) for conventional cigarettes and 10.5% (n=288) for e-cigarettes. Prior waterpipe smoking significantly predicted cigarette use (adjusted relative risk (ARR)=1.81, 95% CI 1.19-2.76), as well as e-cigarette use (ARR=3.29, 95% CI 2.53-4.28). In addition, a significant interaction between waterpipe use and sensation seeking was found (ARR=0.56, 95% CI 0.33-0.95), with waterpipe use being more predictive of later e-cigarette initiation for lower sensation-seeking individuals. DISCUSSION: Waterpipe use predicted both later cigarette and e-cigarette use independent of all other assessed risk factors, indicating that waterpipe use might be a risk factor on its own. The results suggest that the association was stronger for adolescents with a lower risk-taking propensity, which brings this group into focus for prevention efforts. However, further research is needed to understand whether these associations are causal.

[Unplanned pregnancy-now what? : Effectiveness and acceptance of medical teaching units for primary and secondary prevention in schools]. / Ungeplant schwanger ­ wie geht es weiter? : Wirksamkeit und Akzeptanz ärztlicher Interventionen zur Primär- und Sekundärprävention an Schulen.

BACKGROUND: The German Medical Society for Health Promotion (ÄGGF) has developed a school-based teaching unit for students in grade 8 and higher that aims at primary and secondary prevention of unplanned pregnancies. AIMS: The accompanying evaluation study analyzes the effects of the teaching unit on the students' knowledge and their experience with self-efficacy concerning unplanned pregnancies. METHODS: A two-armed cluster-randomized controlled study was conducted using a ten-page anonymous questionnaire with a closed answer format before and after the intervention. RESULTS: In the first survey, 1855 students participated; 1523 students participated in the second. Participants in the intervention group showed a greater increase in knowledge over time. Compared to the control group, they showed an increased intention to use the pill and condoms as well as a marked increase in self-efficacy in the case of an unplanned pregnancy. Furthermore, they significantly corrected their perception of the age at which same-aged boys start having sexual intercourse. All effects remained stable when covariates were controlled. The teaching units were highly accepted: more than 90% of the participants stated that they would recommend them to other students. DISCUSSION: A school-based medical teaching unit about the prevention of unplanned teenage pregnancies was able to contribute to the improvement of students' knowledge and competency. The intervention itself was highly accepted within the target group.

["Klar bleiben" (keep a clear head)-a competition for school classes to reduce alcohol consumption]. / "Klar bleiben" ­ ein Wettbewerb für Schulklassen zur Reduktion des Alkoholkonsums.

In Germany, alcohol is the most popular drug among adolescents. So far, school-based alcohol prevention programs have focused on elementary school children and pupils in early adolescence. The school program "Klar bleiben" ("Keep a Clear Head") was especially designed for young people in late adolescence (10th graders) with the aim of establishing non-binge drinking as a social norm.Students in the participating classes commit themselves to abstain from binge drinking for six weeks (contract management). The class gives feedback after each week. After at least five positive feedbacks, the class is rated as successful and enters a prize draw. Elaborated teaching impulses and information resources for teachers and parents are further components of the prevention program.The evaluation of the class competition by 92 teachers can be regarded as consistently positive. The results of a cluster-randomized study showed a relative risk reduction of 10.4% in binge drinking in the last month for those adolescents who had already consumed alcohol before and belong to the intervention group. After the end of the intervention, this group of adolescents consumed an average of 0.19 fewer alcoholic beverages per drinking occasion compared to adolescents from the control group. The findings presented here are encouraging, keeping in mind that the intervention is relatively inexpensive.

["Aktion Glasklar"-an information and awareness campaign to prevent alcohol consumption in adolescence]. / "Aktion Glasklar" ­ eine Informations- und Sensibilisierungskampagne zur Alkoholprävention im Jugendalter.

Due to the prevalence and harmful consequences of alcohol consumption, universal measures for alcohol prevention are also necessary in adolescence. An example of such a universal measure, "Aktion Glasklar," has been implemented mainly in the school setting for more than 15 years. Through print media, lesson proposals, a quiz with regular prize lotteries, and a website including interactive elements, young people are informed about alcohol in an age-appropriate manner and are encouraged to reflect on alcohol critically. Parents receive suggestions on how to address alcohol consumption with their children. For adult caregivers, such as teachers or youth group leaders, Aktion Glasklar provides prepared teaching suggestions. In a cluster-randomized study, the effects of participation in an intervention on alcohol-related knowledge and the frequency of binge drinking were shown. Thus, even a low-threshold and less intensive measure may contribute to the education and reduction of risky forms of consumption in adolescence.

Association between bullying victimization and e-cigarette use among German students.

This study examined the association between bullying victimization and e-cigarette use. Data from a 2019-2020 German student survey were used (N = 16,476). The target population consisted of students enrolled in grades 5-10, with a mean age of 13.1 years (SD = 1.8), and equal gender distribution (49.5% female). Mixed-effect multivariable logistic regression models were used to examine the association between bullying victimization (attacked physically, assaulted verbally, experienced relational bullying, sexual harassment, cyberbullying) and current e-cigarette use. The multivariable analysis controlled for age, sex, sensation-seeking, socioeconomic status, school performance, type of school attended, and substance use (current cigarette smoking, hookah smoking, and alcohol drinking). Overall 510 (3.7%) students reported current use of e-cigarettes. The odds for using e-cigarettes increased each step of being bullied from "never," "rarely," "sometimes," "once a week," to "several times a week" by 2.03 (95% confidence interval [CI]: 1.81, 2.29) in the unadjusted model, and by 1.46 (95% CI: 1.24, 1.71) in the covariate-adjusted model. Data indicate an empirical association between victimization and e-cigarette use among German students. Design limitations prevent the conclusion of a causal relationship, calling for well-designed longitudinal studies to investigate the temporal sequence between victimization and e-cigarette use.

[Smoke-free Germany 2040: a discussion paper]. / Rauchfreies Deutschland 2040: Ein Diskussionsbeitrag.

INTRODUCTION: A "smoke-free" society is assumed if less than 5 % of a population smoke. We predict when this goal could be reached in Germany. To reduce the proportion of smokers in the population, the World Health Organization recommends a bundle of measures (MPOWER) that should minimize both the supply of and the demand for tobacco. The current level of implementation of these recommendations in Germany is presented. METHODS: A total of 21 representative cross-sectional surveys of the Drug Affinity Study and the Epidemiological Survey of Substance Abuse since 2000/2001 with adolescents and adults show the smoking behavior of the population until 2018. Per capita consumption of factory-built and self-made cigarettes during the same period is used as an objective data basis. Regression analyses are used to model the date at which less than 5 % of the German population smoke. A selective literature review is carried out to describe the implementation of the MPOWER program. RESULTS: Before 2000 there was no trend in Germany towards non-smoking. After the implementation of various preventive measures such as price increases for tobacco products and the introduction of non-smoking protection laws, the spread of smoking among the population has steadily decreased since 2000. By 2018, the 5 % prevalence target among adolescents had almost been reached, as the relative proportion of adolescents who smoked fell by 20.9 percentage points to 6.6 %. The relative proportion of smoking in adult women fell by 12.1 percentage points to 18.5 %, the relative proportion of smoking in men by 14.8 percentage points to 24.2 %. Assuming a linear trend, the prevalence target of less than 5 % smoking adults can be reached by around 2043. Of the six recommended measures of the MPOWER program, Germany is currently only implementing the monitoring of tobacco consumption in society without compromises. DISCUSSION: After various tobacco prevention measures were implemented, a trend towards non-smoking began in Germany. The continual price increase recommended by the World Health Organization, the further restriction of availability, the ban on all tobacco advertising and promotion, the support of smoking cessation as well as the education of the population appear to be necessary to reinforce this trend and to achieve the health policy goal of a smoke-free society in 2040.

[Prediction of binge drinking in young adults: a cohort study over nine years]. / Vorhersage des Rauschtrinkens im jungen Erwachsenenalter: Eine Kohortenstudie über 9 Jahre.

Prediction of binge drinking in young adults: a cohort study over nine years Abstract. OBJECTIVE: Which person characteristics and environmental factors predict binge drinking at age 21? METHOD: A longitudinal observational study with a nine-year follow-up. A total of 5,176 adolescents from the German states Schleswig-Holstein and Saxony-Anhalt were surveyed in 2006 with paper-pencil questionnaires (mean age 12.6 years, SD = 0.6). A follow-up assessment was conducted in the year 2015. Baseline predictors were age, gender, school type, school performance, parenting style, early experience with alcohol, alcohol use of parents, alcohol use of friends, and sensation seeking. Primary outcome in 2015 was binge drinking at least once a month (six or more alcoholic drinks during one drinking occasion). RESULTS: A subsample of 1,087 (20.9 %) of the former students could be surveyed nine years after baseline (mean age 21.6 years, SD = 0.8). One out of four (25.4 %) reported binge drinking at least once in a month. A multiple regression model revealed three significant predictors of binge drinking: male gender, early experience with alcohol and frequency of parental alcohol use at baseline. CONCLUSIONS: Perceived frequency of parental alcohol use might be an important risk factor for children's alcohol use in early adulthood. Parents need to reflect their role as alcohol-specific socialization agents.

[School-based tobacco prevention: the "Be Smart - Don't Start" program]. / Tabakprävention im Setting Schule am Beispiel von "Be Smart ­ Don't Start".

The competition for smoke-free classes, the "Be Smart - Don't Start" program has been implemented in Germany since 1997. Using contract management techniques, school classes participating in the competition commit themselves to abstain from smoking for six months. Classes report on a regular basis whether they have stayed smoke-free or not. After the end of the competition period, successful classes participate in a prize draw. The competition aimes to influence social norms.Over the past 20 years, the competition has become a major school-based intervention to prevent smoking in Germany. Several studies addressed process and outcome evaluation, cost-benefit efficacy and iatrogenic effects. Following the evidence so far, the intervention is feasible for implementation in school routines, evokes positive feedback in teachers and students, and reveals a positive cost-benefit ratio. Findings from controlled studies imply that negative side-effects are unlikely to occur and that participation in the competition affects the progression of smoking positively at least in the short term.

Effects of a School-Based Pedometer Intervention in Adolescents: 1-Year Follow-Up of a Cluster-Randomized Controlled Trial.

BACKGROUND: Physical activity (PA) is one of the most important health behaviors that may be modified by each individual. To foster PA in adolescents, a school-based intervention was evaluated. METHODS: A cluster-randomized controlled trial with preassessment in 2014 and follow-up assessment in 2015 included 29 schools with 1020 students (47.6% girls, mean age = 13.69 years). Intervention students received pedometers and monitored their steps for 12 weeks. Classes with the most steps were awarded. Primary outcomes included moderate-to-vigorous PA, out-of-school sports activities, active transport assessed through questionnaires, as well as cardiorespiratory fitness measured using the 20-m shuttle-run test and anthropometric data (weight, height, body fat, and waist circumference) assessed by study staff. RESULTS: Significant interaction terms between group and time were found for all 3 indicators of PA; intervention students showed a higher increase of PA than control students. The same pattern was shown for cardiorespiratory fitness, but the effect missed significance. A more favorable development for the intervention students was shown for body fat and waist-to-height ratio, while there was no effect on body mass index percentile. CONCLUSIONS: An easy way to administer school-based PA program may enhance students' leisure-time PA even 1 year after the intervention has ended.

Motivational Aspects and Critical Issues of a Pedometer Intervention in Adolescents.

BACKGROUND: Existing research shows significant effects of pedometer interventions on students' physical activity (PA). The current study investigates motivational aspects of quantitative increases in PA in the course of a school-based pedometer intervention for adolescents using qualitative data analysis. In addition, critical issues regarding pedometer use in adolescence were examined. METHOD: Data were obtained in the "läuft." evaluation trial. Students of the intervention group received pedometers and took part in class competitions over a time period of 12 weeks. Qualitative data were collected through focus groups (n = 34) with students of the intervention group as well as through in-depth interviews with teachers (n = 33) who implemented the intervention. A grounded theory approach was used to analyze qualitative data. RESULTS: Five major motivational aspects for subsequent increases in PA were examined among students participating in the "läuft." PA program issues: (1) affordance of the pedometer, (2) awareness of the own PA, (3) self-determination with regard to time and type of PA, (4) individual goal setting, and (5) social comparison and competition. CONCLUSIONS: Findings provide a deeper understanding of which aspects of pedometer interventions might be especially important in adolescence and help design effective future interventions for the promotion of PA.

Preventing Binge Drinking in Adolescents.

BACKGROUND: In a survey taken in Germany in 2015, 14.1% of the 12- to 17-year-olds surveyed had practiced binge drinking at least once in the preceding 30 days. The school program "Klar bleiben" ("Keep a Clear Head") was designed for and implemented among 10th graders. The participants committed themselves to abstain from binge drinking for 9 weeks. We studied whether this intervention influenced the frequency and intensity of binge drinking. METHODS: This cluster-randomized controlled trial was carried out in 196 classes of 61 schools, with a total of 4163 participants with a mean age of 15.6 years (standard deviation 0.73 years). Data were collected by questionnaire in late 2015, before the intervention and again six months later. The primary endpoints were the frequency of consumption of at least 4 or 5 alcoholic drinks (for girls and boys, respectively) and the typical quantity consumed. This trial was registered in the German Clinical Trials Registry (Deutsches Register Klinischer Studien, DRKS) with the DRKS ID number DRKS00009424. RESULTS: At the beginning of the trial, there was no difference between the intervention group and the control group with respect to the primary endpoints. After the intervention, differences were found among participants who had consumed alcohol before the trial (73.2% of the overall sample): binge drinking at least once in the preceding month was reported by 49.4% of the control group and by 44.2% in the intervention group (p = 0.028). The mean number of alcoholic drinks consumed in each drinking episode was 5.20 in the control group and 5.01 in the intervention group (p = 0.047). CONCLUSION: The intervention was effective only in the large subgroup of adolescents who had previously consumed alcohol: they drank alcohol less often and in smaller amounts than their counterparts in the control group.

Relationship between attention-deficit/hyperactivity disorder and sedentary behavior in adolescence: a cross-sectional study.

Existing studies reveal that high levels of sedentary behavior are associated with more inattention and hyperactivity problems. Since most previous studies used screen time as an indicator of sedentary behavior and assessed symptoms of attention-deficit/hyperactivity disorder (ADHD) by short screening measures which do not allow to distinguish between subtypes of ADHD, the current study aimed to investigate association between different types of sedentary behavior and symptoms and subtypes of ADHD. The current cross-sectional study analyzed data of 913 students (46.1% girls) aged 13-17 years (M = 15.0, SD = 0.6). Using a self-administered questionnaire, screen-based and non-screen-based sedentary behavior and ADHD symptoms were assessed. Linear and logistic regression analyses were conducted. All analyses were adjusted for age, gender, moderate to vigorous physical activity and body mass index. Screen time was related to the total ADHD score (p < 0.001) as well as to the subscales inattention (p ≤ 0.016) and hyperactivity/impulsivity (p ≤ 0.008). Sedentary time without screens was virtually not associated with ADHD. As far as ADHD symptoms are considered as a correlate of sedentary behavior, the type of activity which is pursued sedentarily seems to matter: screen time, but not other non-screen-based sedentary activities should be considered as being a risk factor for ADHD.

Longitudinal Relationships of Fitness, Physical Activity, and Weight Status With Academic Achievement in Adolescents.

BACKGROUND: To examine associations of cardiorespiratory fitness, physical activity (PA) and weight status with academic achievement 1 year later. In addition, the mediating role of psychological variables was tested. METHODS: Longitudinal analyses included 1011 German students (M = 14.1 years, SD = 0.6 years). Cardiorespiratory fitness was determined with the 20 m shuttle run test. Compliance with PA guidelines was assessed through questionnaire. Weight status was based on body mass index percentiles. As proxy of academic achievement students' self-reported grades in Mathematics and German in their midterm report were averaged. Mediation analyses were conducted at follow-up testing general self-efficacy, depressed affect, and attention/hyperactivity problems. RESULTS: High levels of cardiorespiratory fitness predicted higher educational attainment (p = .007), while we found no longitudinal association for PA and weight status (p > .253). However, students being insufficiently physically active at baseline but meet PA guidelines at follow-up showed a significant improvement in educational attainment. The cross-sectional association between PA and academic achievement was mediated by students' general self-efficacy. CONCLUSION: High fitness in adolescence is associated with higher subsequent academic achievement. The promotion of PA might benefit school performance because of enhanced fitness levels in the long-term and positive influences of PA in the shortterm. The association between weight status and educational attainment remains controversial.

[Sedentary Behavior and the health of adolescents]. / Sitzendes Verhalten und die Gesundheit Jugendlicher.

BACKGROUND: In modern societies, adolescents spend about half of their waking hours with sedentary behavior (SB). Therefore, the current study aims at investigating the relationship between SB and adolescents' health. METHODS: A cross-sectional sample of 1296 students (8(th) grade) from 29 schools in Schleswig-Holstein, Germany was surveyed. Mean age was 13.75 years (SD = 0.67), 47.0 % were female. To asses screen-based and non-screen-based SB, moderate to vigorous physical activity as well as further indicators of health behavior (tobacco and alcohol use, diet) a questionnaire was used. Anthropometric data and blood pressure at rest were assessed during a medical testing and cardiorespiratory fitness was assessed by the 20 m-Shuttle-Run-Test. RESULTS: The students spent almost 7 hours a day sedentary. Total SB was positively associated with behavior that is detrimental to health. These associations were detectable only for screen-based SB, not for non-screen-based SB. Cardiorespiratory fitness was associated negatively with total SB, screen-based as well as non-screen-based SB. Associations remained widely stable when moderate to vigorous physical activity was controlled for. There were almost no associations between SB and blood pressure. DISCUSSION: Total SB, but especially screen-based SB seems to be a health risk factor in adolescence independent of physical activity. Besides fostering physical activity, reduction of SB should be a core target behavior in prevention and health promotion.

Polysubstance use patterns and trajectories in vocational students--a latent transition analysis.

BACKGROUND: The transition from late adolescence to early adulthood (16-20 years) represents a time of exploration and self-discovery for many young people. As such, it is often associated with experimentation in substance use. Vocational students in particular report high substance use. Thus, the aim of this study is to examine patterns and trajectories of their substance use behavior. METHODS: On two occasions (interval 18 months), we investigated 5214 students (M=19.39 years; 54% male) from 49 vocational schools in seven German federal states. We identified classes of substance use and trajectories via latent transition analysis, controlling for gender, age, and socio-economic status. Additionally, we investigated work-related (job demands/stress/satisfaction) and psychopathological (depressive symptoms) predictors of substance use via multinomial regressions. RESULTS: We found three latent stages of substance use: low use (baseline: 43%/follow-up: 44%), mainly alcohol use (50%/45%), and polysubstance use (7%/11%). Over time, 10% of alcohol users at baseline transitioned to polysubstance use at follow-up, while there were smaller transition rates (2-9%) between the other stages. Compared to low use, polysubstance use at follow-up was predicted by high job stress (aOR=1.45, 1.07-1.96) at baseline. CONCLUSIONS: High alcohol use is associated with bidirectional transitions in young adults. Hence, future research needs to identify mechanisms of change to identify protective factors. Regarding vocational practice, early stress management seems to be a viable path to prevent polysubstance use in vocational students.

Screen time, weight status and the self-concept of physical attractiveness in adolescents.

Adolescents in modern societies spend about 3 h per day in front of small recreational screens. The present study aims at investigating the relationships between screen time and different indicators of overweight. In addition, associations with the self-concept of physical attractiveness and perceived weight status will be examined. In a total sample of 1228 students (47.5% girls) aged 12-17 years (M = 13.74, SD = 0.68) cross-sectional associations were determined by conducting multiple linear regression analyses. Screen time showed a significant positive dose-response relationship with body mass index percentile, waist circumference, body fat, waist-to-height-ratio, and a negative association with self-concept of physical attractiveness independent of age, gender and moderate to vigorous physical activity. Thus, screen time seems to be associated with adolescent overweight, abdominal obesity, and body dissatisfaction. Reducing adolescents' screen time could be a promising approach for primary prevention of obesity and for the promotion of a positive physical self-concept.

Latent classes of polysubstance use among adolescents-a systematic review.

BACKGROUND: This systematic review aims to summarize latent classes of polysubstance use in adolescents (10-19 years), and to describe predictors of polysubstance use. METHODS: A systematic literature review was conducted in three databases (PUBMED, PsycINFO, PsycARTICLES) to identify peer-reviewed articles on latent classes of adolescent polysubstance use (published through June 30, 2015), and to assess the comparability of their results. RESULTS: 23 studies (N=450-N=419,698) met the inclusion criteria. The studies showed predominantly (18 studies) average to low risk of bias. 17 studies (74%) identified between three or four latent classes, with "no use" or "low use" classes being the largest and "polysubstance use" being the smallest ones. Intermediate classes included extensive single substance use, such as "alcohol only" classes. Polysubstance use classes were unanimously predicted by higher age, higher parental and peer substance use, and poor academic performance, other predictors were highly heterogeneous. CONCLUSIONS: Latent classes deliver solid information on polysubstance use in adolescence. Despite their sample sensitivity, the studies possess manifold similarities, hence, modeling latent classes seems to be an ecologically valid approach to further research, e.g., for subgroup analyses or on substance use trajectories. Finally, latent classes may help to illustrate differential effects and special groups in prevention and treatment that depend on the actual consumption pattern. However, there are certain methodological recommendations to be considered in order to obtain reliable results.