Moral Beauty During the COVID-19 Pandemic: Prosocial Behavior Among Adolescents and the Inspiring Role of the Media.

In this study, we examined whether adolescents helped others during the COVID-19 pandemic and how stories in the media inspired them in doing so. Using an online daily diary design, 481 younger adolescents (M = 15.29, SD = 1.76) and 404 older adolescents (M = 21.48, SD = 1.91) were followed for 2 weeks. Findings from linear mixed effects models demonstrated that feelings of being moved by stories in the media were related to giving emotional support to family and friends, and to helping others, including strangers. Exposure to COVID-19 news and information was found to spark efforts to support and help as well and keeping physical distance in line with the advised protective behaviors against COVID-19. Moreover, helping others was related to increased happiness. Overall, the findings of this study highlight the potential role of the media in connecting people in times of crisis.

Understanding the behavioral determinants of adolescents' water consumption: A cross-country comparative study.

Substituting the consumption of sugar-sweetened beverages (SSB) with that of water can have a positive effect on adolescents' health. However, despite the attention on this topic in the Global North, it is relatively understudied in other regions of the world, such as the Caribbean. To guide the development of future interventions, understanding the factors determining water consumption among Caribbean adolescents is important. This study examined the behavioral determinants of water consumption among adolescents in Aruba (the Caribbean) and compared them to those in the Netherlands (Western Europe). We used a theoretical model that integrates the dominant theoretical perspectives in the field of public health, including theories of planned behavior, social norms, and intrinsic motivation. This cross-country study included 1,584 adolescents from Aruba and the Netherlands (52% girls; M = 12.34 years; SD = 2.14). The data were analyzed using regression analyses. This study found that in Aruba, adolescents with higher scores of intrinsic motivation, friends' descriptive norms, attitudes, and behavioral control regarding water consumption drank more water. Moreover, the associations between water consumption and both intrinsic motivation as well as friends' descriptive norms for adolescents in Aruba were stronger than those found in the Netherlands. These associations imply that it is even more important for Aruban adolescents than Dutch adolescents to be intrinsically motivated or to perceive their friends often consuming water to drink more water. The cross-country comparison implies that future interventions in Aruba aimed at increasing adolescents' water consumption as an alternative to SSB should focus on enhancing their intrinsic motivation while considering their friends' social norms.

Motivating Social Influencers to Engage in Health Behavior Interventions.

Social influencers are widely known as the promotors of purchase behavior as well as for their potential to change health behaviors among individuals in their social networks. For social influencers to be successful in changing behaviors, it is essential that they convey their message in an authentic, original, credible, and persistent manner. In the context of health behavior interventions, this requires a focus on the motivation of social influencers to engage in the intervention. This perspective article describes the importance of motivating social influencers to engage in the desired health behaviors themselves and to promote it within their social network. We briefly describe the current state of knowledge and our empirical experience in implementing health interventions with social influencers. Using insights from self-determination theory, we demonstrate how social influencers can be motivated optimally in health behavior interventions and, thereby, improving the success of the intervention. To illustrate these insights and guide intervention practice, we provide concrete examples of techniques that can be applied in health interventions involving social influencers. We conclude with directions for further research and intervention practice to improve the delivery of health behavior interventions.

Daily prosocial actions during the COVID-19 pandemic contribute to giving behavior in adolescence.

Prosocial actions are a building block for developing mature and caring social relations. However, the global pandemic may hamper adolescents' prosocial actions. In this preregistered study, we examined the extent to which adolescents provided daily emotional support during the COVID-19 pandemic. In total, 10-25-year-old high school and university students participated at three timepoints (N = 888 at the first timepoint (May 2020); 494 at the second timepoint (Nov 2020) and 373 at the third timepoint (May 2021)). At the first and second timepoint, participants completed 2 weeks of daily diaries on providing emotional support. At all timepoints, participants performed Dictator Games to measure giving to peers, friends and COVID-19 targets (medical doctors, COVID-19 patients, individuals with a poor immune system). Across the three timepoints, adolescents gave more to COVID-19 targets than peers and friends, but giving to COVID-19 target was highest in the beginning of the pandemic (first timepoint relative to second and third timepoint). Results from the first timepoint showed that emotional support directed to friends peaked in mid-adolescence, whereas emotional support towards family members showed a gradual increase from childhood to young adulthood. Furthermore, daily emotional support increased between the first and second timepoint. Daily emotional support to friends predicted giving behavior to all targets, whereas emotional support to family was specifically associated with giving to COVID-19 targets. These findings elucidate the relation between daily actions and prosocial giving to societally-relevant targets in times of crisis, underlying the importance of prosocial experiences during adolescence.

Mood and emotional reactivity of adolescents during the COVID-19 pandemic: short-term and long-term effects and the impact of social and socioeconomic stressors.

Adolescence is a formative period for socio-emotional development which is threatened by the COVID-19 pandemic. The current longitudinal study examined two aims: (1) the short- and long-term effects of the pandemic on young people's mood (i.e. vigor, tension, and depression levels) and emotional reactivity (i.e. fluctuations in daily mood), and (2) the impact of stressors on mood, emotional reactivity, self-oriented (i.e. maladaptive behavior towards COVID-19 rules) and other-benefitting behaviors (i.e. behavior aimed at helping and comforting others). We conducted an online two-week daily diary study among 462 Dutch adolescents (Mage = 15.27 years, 64% females) and 371 young adults (Mage = 21.49 years, 81% females) in May 2020, with a follow-up in November 2020 (N = 238 and 231, respectively adolescents and young adults). In May 2020, young adults and older relative to younger adolescents showed higher levels and more fluctuations in tension and depression and lower levels of vigor. Vigor levels decreased and tension and depression levels increased between May 2020 and November 2020, especially for younger adolescents. There were positive associations between instability of negative emotions (i.e. tension and depression fluctuations) and the exposure to stressors (i.e. family stress and inequality of online homeschooling) in the adolescent sample. Together, this study demonstrates vulnerability regarding young people's mood and emotional reactivity during the COVID-19 pandemic, especially for adolescents who experience more stressors.

Promoting water consumption among Dutch children: an evaluation of the social network intervention Share H2O.

BACKGROUND: There is a need to develop and improve interventions promoting healthy drinking behaviors among children. A promising method could be to stimulate peer influence within children's social networks. In the Share H2O social network intervention (SNI), peer influence was utilized by selecting a subset of influential children and training them as 'influence agents' to promote water consumption-as an alternative to SSBs. Previous research has mainly focused on the process of selecting influence agents. However, the process of motivating influence agents to promote the behavior has hardly received any research attention. Therefore, in the SNI Share H2O SNI, this motivation process was emphasized and grounded in the self-determination theory (SDT). This study evaluated the implementation of the Share H2O SNI, focusing on whether and how applying SDT-based techniques can motivate the influence agents and, indirectly, their peers. METHODS: This study included data collected in the Netherlands from both the influence agents (n = 37) and the peers (n = 112) in the classroom networks of the influence agents. Self-reported measurements assessed the influence agents' enjoyment of the training, duration and perceived autonomy support during the training, and changes in their intrinsic motivation and water consumption before and after the start of the intervention. Changes in the peers' intrinsic motivation, perceived social support, and social norms were measured before and after the start of the intervention. RESULTS: The influence agents enjoyed the training, the duration was adequate, and perceived it as autonomy supportive. There was an increase in the influence agents' intrinsic motivation to drink water and their actual water consumption. Providing personal meaningful rationales seemed to have motivated the influence agents. The intrinsic motivation and perceived descriptive norm of the peers remained stable. The peers reported an increase in their perceived social support and injunctive norm concerning water drinking after the intervention. Influence agents appeared to mainly use face-to-face strategies, such as modeling, talking to peers, and providing social support to promote the behavior. CONCLUSIONS: The current findings provided preliminary evidence of the promising effects of using SDT-based techniques in an SNI to motivate the influence agents and, indirectly, their peers. TRIAL REGISTRATION: NTR, NL6905, Registered 9 January 2018, https://www.trialregister.nl/trial/6905.

An integrated model of fruit, vegetable, and water intake in young adolescents.

OBJECTIVE: In this study, we tested an integrated model for why young adolescents consume fruit, vegetables, and water. The model was based on evidence from studies applying three dominant theoretical approaches, including planned behavior, social norms, and intrinsic motivation. METHOD: The integrated model was tested with structural equation modeling using four data-collection waves of the MyMovez Project (MyMovez, 2017) in which 953 young adolescents (53.9% girls; Mage = 11.19, SDage = 1.36) participated. Self-reported measures were used to assess young adolescents' fruit, vegetable, and water consumption, self-efficacy, attitude, social norms of parents and peers, behavioral intentions, and intrinsic motivation. RESULTS: The analyses revealed that young adolescents' intrinsic motivation to eat fruits and vegetables or drink water predicted changes in their fruit, vegetable, and water consumption. Furthermore, adolescents' perceived descriptive norm of parents (i.e., perception of the prevalence of their parents' water consumption) also predicted changes, but only for water consumption. CONCLUSION: The current findings show that young adolescents' intrinsic motivation (and, to some extent, parental social norms) is the strongest predictor of their consumption of fruit, vegetables, and water. It is important to note, behavioral intentions do not predict their actual behavior over time. Consequently, interventions should focus on increasing young adolescents' intrinsic motivation to perform the targeted behavior while incorporating the influence of the social context. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

What parents can do to keep their children from smoking: A systematic review on smoking-specific parenting strategies and smoking onset.

AIM: To provide a systematic overview of longitudinal studies on different smoking-specific parenting practices (i.e., perceived parental norms and influences, smoking-specific monitoring, availability of cigarettes at home, household smoking rules, non-smoking agreements, smoking-specific communication, and parental reactions) as useful tools in the prevention of youth smoking. METHOD: MEDLINE and PsychINFO search identified 986 studies published from 1990 to December 2016. Two independent researchers identified eligible studies. Study quality was assessed using Newcastle Ottawa Scale (NOS). RESULTS: The systematic search resulted in 1 to 14 longitudinal studies per parenting practice. Studies scored between 4 and 9 on the NOS, indicating an overall moderate quality. The results of complete smoking house rules showed a preventive effect on smoking onset. Furthermore, availability of cigarettes, frequency and quality of communication, parental reaction (i.e., conflict engagement) and norms showed significant and non-significant effects. Significant results were in line with expectations: availability of cigarettes and frequent communication about smoking predicted smoking, whereas a high quality of communication, negative reactions or punishments and setting norms by parents showed a preventive effect. No effects were found for non-smoking agreements. The number of studies was too limited to draw conclusions about other parenting strategies. More research on (1) reliable and valid instruments, (2) other stages of smoking in addition to onset, and (3) potential moderators and mediators is warranted. CONCLUSION: While evidence supports the effectiveness of smoking-specific parenting, further research is required.

A social network-based intervention stimulating peer influence on children's self-reported water consumption: A randomized control trial.

UNLABELLED: The current pilot study examined the effectiveness of a social network-based intervention using peer influence on self-reported water consumption. A total of 210 children (52% girls; M age = 10.75 ± SD = 0.80) were randomly assigned to either the intervention (n = 106; 52% girls) or control condition (n = 104; 52% girls). In the intervention condition, the most influential children in each classroom were trained to promote water consumption among their peers for eight weeks. The schools in the control condition did not receive any intervention. Water consumption, sugar-sweetened beverage (SSB) consumption, and intentions to drink more water in the near future were assessed by self-report measures before and immediately after the intervention. A repeated measure MANCOVA showed a significant multivariate interaction effect between condition and time (V = 0.07, F(3, 204) = 5.18, p = 0.002, pη(2) = 0.07) on the dependent variables. Further examination revealed significant univariate interaction effects between condition and time on water (p = 0.021) and SSB consumption (p = 0.015) as well as water drinking intentions (p = 0.049). Posthoc analyses showed that children in the intervention condition reported a significant increase in their water consumption (p = 0.018) and a decrease in their SSB consumption (p < 0.001) over time, compared to the control condition (p-values > 0.05). The children who were exposed to the intervention did not report a change in their water drinking intentions over time (p = 0.576) whereas the nonexposed children decreased their intentions (p = 0.026). These findings show promise for a social network-based intervention using peer influence to positively alter consumption behaviors. TRIAL REGISTRATION: This RCT was registered in the Australian New Zealand Clinical Trials Registry (ACTRN12614001179628). Study procedures were approved by the Ethics Committee of the Faculty of Social Sciences at Radboud University (ECSW2014-1003-203).

Exposure to Movie Reckless Driving in Early Adolescence Predicts Reckless, but Not Inattentive Driving.

OBJECTIVE: We examine the association between exposure to depictions of reckless driving in movies and unsafe driving, modeling inattentive and reckless driving as separate outcomes. METHODS: Data were obtained by telephone from 1,630 US adolescents aged 10 to 14 years at baseline who were drivers at a survey 6 years later. Exposure to movie reckless driving was measured based on movies seen from a randomly selected list of 50 movie titles that had been content coded for reckless driving among characters. Associations were tested with inattentive and reckless driving behaviors in the subsequent survey-controlling for baseline age, sex, socioeconomic status, parental education, school performance, extracurricular activities, daily television and video/computer game exposure, number of movies watched per week, self-regulation and sensation seeking. RESULTS: Exposure to movie reckless driving was common, with approximately 10% of movie characters having driven recklessly. Confirmatory factor analysis revealed a significant distinction between items tapping reckless and inattentive driving at the 6th wave. Age and exposure to movie reckless driving at baseline were directly associated with wave-6 reckless (but not inattentive) driving. Additionally, growth in sensation seeking mediated a prospective relation between the total number of movies watched per week at baseline and reckless driving, independent of exposure to movie reckless driving. Males and high sensation seekers reported lower seatbelt usage and more reckless driving, whereas lower self-regulation predicted inattentive driving. DISCUSSION: In this study, exposure to movie reckless driving during early adolescence predicted adolescents' reckless driving, suggesting a direct modeling effect. Other aspects of movies were also associated with reckless driving, with that association mediated through growth in sensation seeking. Predictors of reckless driving were different from predictors of inattentive driving, with lower self-regulation associated with the latter outcome. Making a clear distinction between interventions for reckless or inattentive driving seems crucial for accident prevention.

Parental co-viewing and susceptibility for smoking and drinking in adolescents: an experimental pilot study.

BACKGROUND AND OBJECTIVES: The current pilot study is the first experiment to examine whether parents are able to diminish the adverse influences of smoking and drinking depicted in movies through co-viewing. METHODS: For this study, 99 adolescents (M = 12.82 years old; SD = .95; 38.8% boys) watched the 3D version of Titanic in the cinema. Through randomization, adolescents were invited to come with either a parent or a friend. After watching the movie, adolescents filled out a questionnaire that assessed their susceptibility for smoking and drinking and their social images concerning these behaviors. RESULTS: The findings revealed that adolescents who co-viewed the movie with their parents, compared to with their friends, were at the same or an even higher risk for future smoking or drinking after watching the movie. The findings also indicated that only a few parents communicated about smoking and drinking while watching the movie. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: Simply co-viewing might not be an effective way for parents to blunt the effect of smoking and drinking in movies. In addition to ensuring more caution when advising parents to simply co-view movies, the present findings encourage additional research on the impact of instructive mediation strategies.

The associations of anticipated parental reactions with smoking initiation and progression in adolescents.

BACKGROUND AND OBJECTIVES: The aim of this study was to examine whether anticipated parental reactions to smoking were related to smoking onset and progression during adolescence. METHODS: Data were used from the six-wave, 5-year longitudinal "Family and Health" project, in which N = 428 adolescents (M = 13.4, SD = .50; 52.3% girls) and their families participated. RESULTS: Parental reactions, as anticipated by adolescents, included benign indifference, conflict engagement, disclosing disappointment, and positive problem-solving. Findings of discrete-time survival analyses indicated no direct association between anticipated reactions at baseline and smoking onset within 5 years. However, a significant interaction effect was found between parental smoking and anticipated parental disappointment. This finding indicates that adolescents of non-smoking parents, who expected reactions of annoyance and disappointment, were less at risk for initiating smoking than adolescents from smoking parents who expected such reactions. None of the anticipated parental reactions were significantly related to smoking progression, neither directly nor indirectly. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: Findings from this study suggest that focusing on anticipated reactions to smoking is probably not the most promising endeavor for effective smoking prevention and intervention.

The changing role of self-efficacy in adolescent smoking initiation.

BACKGROUND: Refusal self-efficacy is assumed to be linked to adolescent smoking. The aim of the present study was to examine the changing role of self-efficacy in adolescent smoking over time while controlling for parental, sibling, and friends' smoking. METHODS: This study used data from five annual waves of the "Family and Health" project. A total of 428 adolescents (mean age = 13.3 years; standard deviation = .48) and their parents participated at baseline. Only never smokers at baseline (n = 272) were included to measure smoking initiation. First, the effects of baseline self-efficacy, parental, sibling, and friends' smoking on adolescent smoking initiation at measurement five were examined. Second, with latent growth curves analyses, individual growth curve parameters of adolescent smoking, self-efficacy, parental, sibling, and friends' smoking were calculated. Subsequently, these growth parameters were used to predict growth of adolescent smoking. RESULTS: Findings showed that baseline self-efficacy, parental and friends' smoking did not predict adolescent smoking at wave five, but baseline sibling smoking did. However, growth curve parameters showed that a decrease in self-efficacy, an increase in proportion of smoking friends, and an increase in sibling smoking over time were related to an increase in adolescent smoking. Initial levels of sibling and friends' smoking moderated the link between self-efficacy and adolescent smoking over time. CONCLUSION: A decrease in self-efficacy over time, rather than baseline self-efficacy, is associated with smoking initiation in adolescence. Findings emphasize the need for more fine-grained analyses when looking at self-efficacy or other individual characteristics that might fluctuate over time.

'One cigarette for you and one for me': children of smoking and non-smoking parents during pretend play.

OBJECTIVE: To investigate whether perceived parental smoking is related to pretend smoking in young children and whether children influence each other in pretend smoking. METHODS: Children who reported to have at least one smoking parent were coupled with children who had non-smoking parents. Both children were then asked to pretend that they were adults having a barbeque party. During their role playing, the children were observed in order to assess their pretend smoking behaviours and to examine whether children of smoking parents were more likely to initiate pretend smoking. Children were tested at their schools; the sample consisted of 206 children between 4 and 7 years of age (mean age=5.14, SD=0.87), of which 54.4% were girls. The main outcome was whether a child pretended to be smoking and whether the child initiated or followed the other child in this behaviour. RESULTS: During their play, 63.6% (n=131) of the children pretended to smoke. Children of smoking parents were more likely to initiate pretend smoking than to follow. CONCLUSIONS: Through their own smoking, parents appear to be able to influence the way in which their children interact with peers regarding pretend smoking. More specifically, children of smoking parents might instigate smoking among their peers.

Effects of parents' education and occupation on adolescent smoking and the mediating role of smoking-specific parenting and parent smoking.

The current study examined the independent effects of parents' educational attainment and occupational status on adolescent smoking and mediation of smoking-specific communication and parents' smoking behaviours on this link. Data were collected in a multi-informant, full-family design in two sampling waves separated by 3 years (n = 358). Education, occupational status, communication, and smoking were assessed via parent and child report. Different effects were found for the indicators of father and mother's socioeconomic status (education and occupation) for three study outcomes (adolescent lifetime smoking, smoking onset, and smoking continuation). Bootstrapping procedures revealed no mediation in any of the socioeconomic status adolescent smoking associations. Study limitations and implications are discussed.

Association of smoking onset with R-rated movie restrictions and adolescent sensation seeking.

OBJECTIVES: In this study, we examined how often US youths reported having complete parental restrictions on watching R-rated movies. In addition, we assessed the relationship between parental R-rated movie restrictions and adolescents' sensation seeking and how this interplay is related to smoking onset. METHODS: Data from a 4-wave longitudinal study of 6522 adolescents (10-14 years of age) who were recruited through a random-digit-dial telephone survey were used. At baseline, subjects were nationally representative of the US population. Subjects were monitored for 2 years and queried about their smoking status, their sensation-seeking propensity, and how often they were allowed to watch R-rated movies. A cross-lagged model combined with survival analysis was used to assess the relationships between parental R-rated movie restrictions, sensation-seeking propensity, and risk for smoking onset. RESULTS: Findings demonstrated that 32% of the US adolescents reported being completely restricted from watching R-rated movies by their parents. Model findings revealed that adolescents' sensation seeking was related to greater risk for smoking onset not only directly but also indirectly through their parents becoming more permissive of R-rated movie viewing. Parental R-rated movie restrictions were found to decrease the risk of smoking onset directly and indirectly by changing children's sensation seeking. CONCLUSIONS: These findings imply that, beyond direct influences, the relationship between adolescents' sensation seeking and parental R-rated movie restrictions in explaining smoking onset is bidirectional in nature. Finally, these findings highlight the relevance of motivating and supporting parents in limiting access to R-rated movies.

Facial attractiveness and self-esteem in adolescence.

Facial attractiveness has been associated with many (social) advantages in life, like greater popularity, acceptance, and social competence. Because social evaluations and acceptance are important factors contributing to self-esteem (SE), we hypothesized that high levels of attractiveness would be related to increased levels of SE. To test this assumption, 230 adolescents from two age groups (13 and 15 years) were surveyed annually for 5 years. A latent growth curve model was used to model the influence of facial attractiveness on the development of SE over time. Results showed that younger adolescents with higher levels of attractiveness had lower levels of SE at baseline. Attractiveness was not found to be a significant predictor in explaining the development of SE over time. These findings indicate that attractive children are more likely to have lower levels of SE when they enter early adolescence compared to their less attractive counterparts.

Parental smoking and pretend smoking in young children.

OBJECTIVE: To investigate whether parental smoking was associated with smoking-related play behaviour in young children. DESIGN: Children were asked to pretend that they were grown-ups having dinner. They were invited to act out this situation in a play corner with a toy kitchen and a child-sized dining area, including a package of fake cigarettes on the table. SETTING: Children were tested individually at their school during regular school hours. PARTICIPANTS: The sample consisted of 100 children between 4 and 8 years of age (mean=5.28, SD=0.94) of which 57% were boys. The majority of the children were born in The Netherlands (99%). MEASUREMENTS: The main outcome measure was whether or not a child pretended to be smoking a cigarette. Child and parent reports were used to assess parental smoking. FINDINGS: Findings revealed that 37% of the children had at least one 'puff' during their play. Children were more likely to pretend to smoke if they reported having smoking parents (OR=3.16, p=0.02; 95% CI=1.22 to 8.18). Analyses for the model with parent reports on parental smoking did not yield any direct association. Children's explicit attitudes were unrelated to their smoking-related play behaviour. CONCLUSIONS: These findings indicate that young children, who reported having parents who smoke, already associate having dinner with a (after-dinner) cigarette.

Do interactions between personality and social-environmental factors explain smoking development in adolescence?

This study examined if the effects of peer smoking, family smoking, and parenting on smoking development during adolescence are moderated by personality characteristics of adolescents. Longitudinal data were obtained from 428 adolescents (aged M = 13.4, SD = .50) and their parents. Latent Growth Curve models assessed the development of smoking as a function of predictors and if effects of smoking-specific parenting and exposure to smoking were moderated by adolescents' Big Five personality dimensions. Findings revealed that having peers who smoked was associated with an increased likelihood of being a smoker at baseline. Further, significant interactions revealed that adolescents lower in agreeableness were more likely to be a smoker at baseline if they had an older sibling who smoked or if their parents engaged in frequent smoking-related discussions with them and that effective smoking-specific conversation was more strongly related to smoking at baseline among adolescents who were highly emotionally stable. No interactions predicted growth in smoking over time yet significant main effects showed that growth in smoking was associated with higher levels of extraversion, lower levels of emotional stability, and less effective parental smoking-specific communication. This study highlights the relevance of personality-target interventions and policy programs directed at parents and peers.

Relative risks of exposure to different smoking models on the development of nicotine dependence during adolescence: a five-wave longitudinal study.

PURPOSE: Many studies have focused upon predictors of smoking onset and continuation in adolescents. However, less is known about the development of nicotine dependence (ND) and how smoking in the interpersonal environment relates to this. To examine which smoking models have the largest impact on the development of ND, we examined the relative impact of current smoking from fathers, mothers, siblings, best friends, and friend groups on the development of ND in adolescents. METHODS: Data were used from five annual waves of the "Family and Health" survey project. At baseline 428 adolescents (mean age=15.2 years; SD=.60), both their parents, and their siblings were participating. In this study we included only smoking adolescents (n=175). To assess the individual development of ND of each adolescent, and whether current smoking exposure affected changes from baseline across time, we used latent growth curve modeling (LGC). RESULTS: Findings revealed that smoking of sibling and best friend were related to baseline levels of ND, but not to the rates of change over time. Of all models, only having smoking friends in the friend group was related to a faster development of ND. CONCLUSIONS: The current findings highlight the key role of smoking friends in the development of ND and suggest that interventions targeting at peers are probably effective in reducing the prevalence of ND symptoms among adolescents.