The bidirectional associations between self-esteem and problematic eating behaviors in adolescents.

OBJECTIVE: Theories propose that low self-esteem and problematic eating behaviors (PEBs) negatively impact each other. While previous studies suggested bidirectional associations between self-esteem and PEBs, they did not separate within-person from between-person associations. Therefore, this prospective study investigated the within-person bidirectional associations between self-esteem and four PEBs in adolescence, while accounting for between-person differences. METHOD: We used two independent longitudinal samples of Dutch adolescents, each including three annually collected waves of data. Sample 1 consisted of 1856 adolescents (Baseline: 50.4% males; Mage = 13.79 years, SDage = 0.72), with measures of self-esteem, emotional eating, restrained eating, and loss of control (LOC) while overeating. Sample 2 consisted of 555 adolescents (Baseline: 49.7% males; Mage = 13.13 years, SDage = 0.68), with measures of self-esteem and LOC eating. The data were analyzed using random intercept cross-lagged panel models (CLPMs). RESULTS: Within persons, lower self-esteem was associated with higher emotional and restrained eating (both Sample 1) one year later, and vice versa. Self-esteem did not predict, nor was predicted by, LOC while overeating (Sample 1) or LOC eating (Sample 2). Between persons, self-esteem was negatively correlated with all PEBs (Samples 1 and 2). DISCUSSION: We found within-person bidirectional associations between low self-esteem and emotional and restrained eating (but not LOC while overeating/LOC eating), and between-person correlations between low self-esteem and all PEBs. These results have theoretical and practical implications. Within-person processes clarify underlying mechanisms that explain the occurrence of PEBs; between-person associations are important to identify adolescents at risk of PEBs. PUBLIC SIGNIFICANCE: While theories indicate that low self-esteem and PEBs are inversely associated within individuals, empirical studies have not disentangled within-person processes from between-person differences. This study addressed this disparity, finding that lower self-esteem was bidirectionally associated with higher emotional and restrained eating (but not LOC eating) within persons. These findings suggest that enhancing self-esteem is a viable option for prevention and intervention.

Self-esteem and negative affectivity as mediators of the prospective links between adolescent interpersonal peer problems and disordered eating behaviors.

The current prospective study examined whether both self-esteem and negative affectivity mediate subsequent associations between interpersonal peer problems (i.e., peer victimization, peer rejection, lack of friendships) and disordered eating behaviors (i.e., loss of control while overeating, emotional eating, restrained eating) in adolescents using secondary data. The sample included 2051 adolescents (Mage baseline = 13.81, SDage baseline = 0.72; 48.5% female) who participated in a longitudinal project, which includes three annually collected waves of data. Participants completed self-report and peer-report measures describing interpersonal problems with peers, and self-report measures describing negative affectivity, self-esteem, and disordered eating behaviors. The results provided no support for either self-esteem or negative affectivity as mediators of the associations between interpersonal peer problems and disordered eating behaviors two years later. However, self-esteem was more robustly linked to all three types of subsequent disordered eating behaviors than negative affectivity. This highlights the importance of adolescent's self-evaluations in the development of disordered eating behaviors.

A longitudinal study on changes in food parenting practices during COVID-19 and the role of parental well-being.

The COVID-19 pandemic may negatively influence food parenting practices, also among parents of adolescents. Parental well-being (stress and depressive symptoms) may explain these COVID-19 related changes in food parenting practices (snack structure, healthy structure, modeling, autonomy support, and coercive control). However, most previous studies performed before or during the COVID-19 pandemic have been limited by cross-sectional designs. The aim of the current study among parents of adolescent children was twofold. First, we aimed to examine prospective differences in food parenting practices comparing the situation before and during COVID-19. Second, we aimed to examine both cross-sectional and longitudinal associations between parental well-being and the dimensions of food parenting, while additionally examining whether these prospective associations were more pronounced in parents who had experienced more COVID-19 stressful life events. Parents (N = 290; 74.9% female; at baseline: Mage = 46.9; SDage = 4.3) of adolescent children (at baseline: Mage = 14.3; SDage = 0.6) completed online surveys about parental well-being and food parenting twice: One year before the COVID-19 pandemic (spring 2019) and during the COVID-19 pandemic, 1.5 years after the first measurement (autumn 2020). In general, we found consistent evidence for an average decrease in food autonomy support and an increase in coercive control during COVID-19. However, parental well-being did not seem to explain (changes in) food parenting practices during COVID-19, also not in combination with stressful life events. Our findings suggest that, regardless of parental well-being, the general COVID-19 situation had some small negative influences on autonomy support and coercive control among parents of adolescents. These findings might be explained by parents being more often confronted with unhealthy eating occasions in the COVID-19 home context, triggering these negative parental responses.

Examining food intake similarities in adolescent best friend dyads using longitudinal Actor-Partner Interdependence Models.

Little is known about how adolescent best friends may affect each other's food intake. This study explored whether friendship selection and socialization mechanisms explained potential food intake similarities in adolescent reciprocated best friend dyads. We also tested whether socialization processes were moderated by dyad member's relative zBMI. Members of 145 same-gender best friendship dyads (56% female; Mage = 12.79; SDage = 0.61) reported on their intake of food obtained from home and from outside the home at the beginning and the end of the school year through food frequency questionnaires. Longitudinal Actor-Partner Interdependence Models results showed no indication of selection or socialization, and very limited evidence for the moderation of socialization processes by relative zBMI. These findings indicate that focusing on adolescent reciprocated best friends in dietary interventions may not be valuable.

Promoting water consumption among children: a three-arm cluster randomised controlled trial testing a social network intervention.

OBJECTIVE: To test the effectiveness of a social network intervention (SNI) to improve children's healthy drinking behaviours. DESIGN: A three-arm cluster randomised control trial design was used. In the SNI, a subset of children were selected and trained as 'influence agents' to promote water consumption-as an alternative to sugar-sweetened beverages (SSB)-among their peers. In the active control condition, all children were simultaneously exposed to the benefits of water consumption. The control condition received no intervention. SETTING: Eleven schools in the Netherlands. PARTICIPANTS: Four hundred and fifty-one children (Mage = 10·74, SDage = 0·97; 50·8 % girls). RESULTS: Structural path models showed that children exposed to the SNI consumed 0·20 less SSB per day compared to those in the control condition (ß = 0·25, P = 0·035). There was a trend showing that children exposed to the SNI consumed 0·17 less SSB per day than those in the active control condition (ß = 0·20, P = 0·061). No differences were found between conditions for water consumption. However, the moderation effects of descriptive norms (ß = -0·12, P = 0·028) and injunctive norms (ß = 0·11-0·14, both P = 0·050) indicated that norms are more strongly linked to water consumption in the SNI condition compared to the active control and control conditions. CONCLUSIONS: These findings suggest that a SNI promoting healthy drinking behaviours may prevent children from consuming more SSB. Moreover, for water consumption, the prevailing social norms in the context play an important role in mitigating the effectiveness of the SNI.

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.

Schema therapy with exposure and response prevention for the treatment of chronic anxiety with comorbid personality disorder.

BACKGROUND AND OBJECTIVES: A considerable group of patients with anxiety disorders do not respond to guideline CBT treatment, possibly due to comorbid personality disorder (PD) traits. Schema therapy (ST) is an integrative treatment for personality disorders, and preliminary evidence suggests that it also affects anxiety. The present study examined the effects of a combination treatment ('SCHerp': ST + exposure and response prevention) in a non-responsive outpatient group suffering from chronic anxiety and comorbid cluster C personality disorder. METHODS: Psychological malfunction (n = 42), and adaptive and maladaptive schema modes (n = 49) were assessed pre- and post-treatment. RESULTS: Patients showed statistically significant decreases in psychological malfunction and maladaptive modes, and significant increases in adaptive modes from pre- to post-treatment. Changes in modes were correlated with changes in psychological malfunction. LIMITATIONS: No control group or follow-up measurements were included. CONCLUSIONS: The combination of ST and exposure with response prevention may be a viable avenue for research and treatment for this subpopulation. However, further research is needed to confirm and enhance effectiveness and identify working mechanisms of SCHerp. PRACTITIONER POINTS: The SCHerp programme combines schema therapy with exposure and response prevention to tackle chronic anxiety in patients with comorbid personality disorder SCHerp significantly reduced psychological malfunction and maladaptive modes, and increased adaptive modes Changes in schema modes correlated with changes in psychological malfunction, suggesting that schema modes are an appropriate treatment target in this population No active control group was included so no therapy-specific factors can be determined at this stage.

Food parenting practices and children's weight outcomes: A systematic review of prospective studies.

This systematic review is the first to provide an overview of the prospective links between food parenting practices and children's weight outcomes. Three databases were searched. All titles, abstracts and full-texts were double screened by two independent reviewers. Peer-reviewed journal articles published after 1990 assessing the prospective association between food parenting practices and weight outcomes of children aged 2-18 years were eligible. A total of 38 eligible studies were identified, focusing on 12 separate food parenting practices. Restriction, pressure to eat, and monitoring were generally not associated with children's weight over time, but higher quality studies suggest that pressure to eat was associated with lower weight outcomes over time. Most studies on food availability and accessibility found null-findings as well. Instrumental-but not emotional-feeding was associated with higher weight over time, but higher quality studies are needed to confirm this link. Results involving the link between frequency of mealtime and child weight were mixed. Autonomy supporting and other structure-related food parenting practices were understudied. In conclusion, food parenting practices receiving the most attention within prospective studies (i.e., restriction, pressure to eat, monitoring) were generally not associated with children's weight outcomes over time. Future high quality studies should focus more on other food parenting practices, further unravel bidirectional links between food parenting and children's eating behaviors and weight outcomes, and examine the mediating role of dietary intake.

Addiction-Focused Eye Movement Desensitization and Reprocessing Therapy as an Adjunct to Regular Outpatient Treatment for Alcohol Use Disorder: Results From a Randomized Clinical Trial.

BACKGROUND: This study examined the feasibility, safety, and efficacy of addiction-focused eye movement desensitization and reprocessing (AF-EMDR) treatment, as an add-on intervention to treatment as usual (TAU). METHODS: Adult outpatients with alcohol use disorder (AUD) (N = 109) who already received or had just started with TAU (Community Reinforcement Approach) were recruited at 6 outpatient addiction care facilities. They were randomly assigned to either TAU + 7 weekly 90-minute sessions of AF-EMDR (N = 55) or TAU-only (N = 54). Assessments were made at baseline, after AF-EMDR therapy (+ 8 weeks in the TAU-only group), and at 1- and 6-month follow-up. The primary outcomes were changes in drinking behavior as reported by the participant and biomarker indices. RESULTS: Data were analyzed as intent-to-treat with linear mixed models. Additionally, sensitivity analyses were performed. No group or interaction effects were found for any of the outcome variables. Only limited change over time was seen with regard to indices of personal and societal recovery and in some secondary indices of clinical recovery (craving, desire thinking, and rumination). Reliable Change Index calculations showed that more TAU-only participants showed clinical improvement with regard to alcohol consumption while a somewhat higher proportion of participants in the TAU + AF-EMDR group experienced less craving. The acceptability, safety, and feasibility of the treatments received in both groups were comparable. CONCLUSIONS: There was no add-on effect of AF-EMDR on TAU with regard to drinking behavior in outpatients with an AUD. Possible explanations are discussed. Future studies should first establish proof of principle regarding the potential of AF-EMDR therapy to disrupt operant learning and habits relevant in addiction.

The reciprocal effects of physical activity and happiness in adolescents.

BACKGROUND: Positive associations exist between physical activity and happiness in adolescents. However, previous studies have mostly used self-reported measures and cross-sectional designs. There is a need for more insight into the directionality and duration of this association. The current study was the first to investigate whether an increase in physical activity leads to happiness and whether adolescents become more physically active when they are happier. These two effects were studied between (on a day-to-day basis) and within days (on an hour-to-hour basis). METHODS: The study used data from the MyMovez project in which 1484 adolescents between the ages of 8 and 17 years wore an accelerometer on their wrist and answered experience sampling questions on happiness at random moments during the day for several weeks in 2016-2018. RESULTS: The preregistered analyses demonstrated an association between physical activity and happiness. More specifically, the number of steps per day predicted the experienced happiness on that day. In addition, a short-term reciprocal effect of physical activity and happiness was observed. Happiness was predicted by the number of steps accumulated in the previous hour and it also predicted the number of steps accumulated in the subsequent hour. However, convincing evidence was found that these effects did not occur in the long-term between days. The number of steps on the previous day did not predict happiness, nor did happiness predict the number of steps of the subsequent day. CONCLUSIONS: This study confirms an association between physical activity and happiness in adolescents and shows that in the short-term, physical activity promotes happiness and vice versa. Therefore, we conclude that physical activity is not only important for the physical health of youth, but also plays an important role in their mental well-being. In addition, this knowledge can be used to further understand the importance of physical activity in adolescents' health and help in promoting a healthy lifestyle among youth. TRIAL REGISTRATION: The data used are stored at the Data Archiving and Networked Services ( https://doi.org/10.17026/dans-zz9-gn44 ). Hypotheses, study design, sample, data collection procedure, measured variables, and plan of analysis were preregistered on the Open Science Framework (OSF, https://osf.io/5yk7r/ ).

Identifying Influence Agents That Promote Physical Activity Through the Simulation of Social Network Interventions: Agent-Based Modeling Study.

BACKGROUND: Social network interventions targeted at children and adolescents can have a substantial effect on their health behaviors, including physical activity. However, designing successful social network interventions is a considerable research challenge. In this study, we rely on social network analysis and agent-based simulations to better understand and capitalize on the complex interplay of social networks and health behaviors. More specifically, we investigate criteria for selecting influence agents that can be expected to produce the most successful social network health interventions. OBJECTIVE: The aim of this study was to test which selection criterion to determine influence agents in a social network intervention resulted in the biggest increase in physical activity in the social network. To test the differences among the selection criteria, a computational model was used to simulate different social network interventions and observe the intervention's effect on the physical activity of primary and secondary school children within their school classes. As a next step, this study relied on the outcomes of the simulated interventions to investigate whether social network interventions are more effective in some classes than others based on network characteristics. METHODS: We used a previously validated agent-based model to understand how physical activity spreads in social networks and who was influencing the spread of behavior. From the observed data of 460 participants collected in 26 school classes, we simulated multiple social network interventions with different selection criteria for the influence agents (ie, in-degree centrality, betweenness centrality, closeness centrality, and random influence agents) and a control condition (ie, no intervention). Subsequently, we investigated whether the detected variation of an intervention's success within school classes could be explained by structural characteristics of the social networks (ie, network density and network centralization). RESULTS: The 1-year simulations showed that social network interventions were more effective compared with the control condition (beta=.30; t100=3.23; P=.001). In addition, the social network interventions that used a measure of centrality to select influence agents outperformed the random influence agent intervention (beta=.46; t100=3.86; P<.001). Also, the closeness centrality condition outperformed the betweenness centrality condition (beta=.59; t100=2.02; P=.046). The anticipated interaction effects of the network characteristics were not observed. CONCLUSIONS: Social network intervention can be considered as a viable and promising intervention method to promote physical activity. We demonstrated the usefulness of applying social network analysis and agent-based modeling as part of the social network interventions' design process. We emphasize the importance of selecting the most successful influence agents and provide a better understanding of the role of network characteristics on the effectiveness of social network interventions.

A randomized controlled trial testing a social network intervention to promote physical activity among adolescents.

BACKGROUND: The current study examined the effectiveness of a social network intervention to promote physical activity among adolescents. Social network interventions utilize peer influence to change behavior by identifying the most influential individuals within social networks (i.e., influence agents), and training them to promote the target behavior. METHOD: A total of 190 adolescents (46.32% boys; M age = 12.17, age range: 11-14 years) were randomly allocated to either the intervention or control condition. In the intervention condition, the most influential adolescents (based on peer nominations of classmates) in each classroom were trained to promote physical activity among their classmates. Participants received a research smartphone to complete questionnaires and an accelerometer to measure physical activity (steps per day) at baseline, and during the intervention one month later. RESULTS: A multilevel model tested the effectiveness of the intervention, controlling for clustering of data within participants and days. No intervention effect was observed, b = .04, SE = .10, p = .66. CONCLUSION: This was one of the first studies to test whether physical activity in adolescents could be promoted via influence agents, and the first social network intervention to use smartphones to do so. Important lessons and implications are discussed concerning the selection criterion of the influence agents, the use of smartphones in social network intervention, and the rigorous analyses used to control for confounding factors. TRIAL REGISTRATION: Dutch Trial Registry (NTR): NTR6173 . Registered 5 October 2016 Study procedures were approved by the Ethics Committee of the Radboud University (ECSW2014-100614-222).

Youth's social network structures and peer influences: study protocol MyMovez project - Phase I.

BACKGROUND: Youth are an important target group for social network interventions, because they are particularly susceptible to the adaptation of healthy and unhealthy habits and behaviors of others. They are surrounded by 'social influence agents' (i.e., role models such as family, friends and peers) that co-determine their dietary intake and physical activity. However, there is a lack of systematic and comprehensive research on the implementation of a social network approach in health campaigns. The MyMovez research project aims to fill this gap by developing a method for effective social network campaign implementation. This protocol paper describes the design and methods of Phase I of the MyMovez project, aiming to unravel youth's social network structures in combination with individual, psychosocial, and environmental factors related to energy intake and expenditure. In addition, the Wearable Lab is developed to enable an attractive and state-of-the-art way of collecting data and online campaign implementation via social networks. METHODS: Phase I of the MyMovez project consists of a large-scale cross-sequential cohort study (N = 953; 8-12 and 12-15 y/o). In five waves during a 3-year period (2016-2018), data are collected about youth's social network exposure, media consumption, socialization experiences, psychological determinants of behavior, physical environment, dietary intake (snacking and drinking behavior) and physical activity using the Wearable Lab. The Wearable Lab exists of a smartphone-based research application (app) connected to an activity tracking bracelet, that is developed throughout the duration of the project. It generates peer- and self-reported (e.g., sociometric data and surveys) and experience sampling data, social network beacon data, real-time physical activity data (i.e., steps and cycling), location information, photos and chat conversation data from the app's social media platform Social Buzz. DISCUSSION: The MyMovez project - Phase I is an innovative cross-sequential research project that investigates how social influences co-determine youth's energy intake and expenditure. This project utilizes advanced research technologies (Wearable Lab) that provide unique opportunities to better understand the underlying processes that impact youths' health-related behaviors. The project is theoretically and methodologically pioneering and produces a unique and useful method for successfully implementing and improving health campaigns.

The longitudinal link between mothers' and adolescents' snacking: The moderating role of television viewing.

A large proportion of adolescents eats too many energy-dense snacks, which is detrimental for their current and future health. To understand how to promote healthy dietary behaviors in adolescents, we need to identify factors that affect their snacking. While previous cross-sectional work has shown mother-child similarities in eating behavior, longitudinal studies are lacking. Hence, the first aim of this study was to examine whether maternal snacking predicted changes in adolescents' snacking over time. A second aim was to examine whether adolescents' television viewing magnified the strength of this longitudinal association. Television viewing may increase the motivation to eat the snacks consumed by mothers later on, for example through food advertisement exposure and mindless eating. To address both aims, 2051 adolescents (Mage baseline = 13.81; 51.5% boys) were asked to report on their snacking and television viewing three times, with intervals of one year. Moreover, a subsample of mothers of adolescents (N = 1080) reported on their snacking at baseline as well. The results indicate that maternal snacking indeed predicts adolescents' snacking over time and that this effect is more pronounced among adolescents who watch a great amount of television. These findings attest to the importance of mothers in forming adolescents' snacking, not only concurrently but also prospectively. Additionally, this study highlights the relevance of assessing other home environmental factors that may influence maternal effects on their children's snacking.

Friendly fire: Longitudinal effects of exposure to violent video games on aggressive behavior in adolescent friendship dyads.

Research on gaming effects has focused on adolescence, a developmental period in which peer relationships become increasingly salient. However, the impact of peers on the effects of violent gaming on adolescents has been understudied. This study examined whether adolescents' exposure to violent video games predicted their own and their friend's aggression one year later. Among 705 gaming adolescents, 141 dyads were identified based on reciprocated best friend nominations (73.8% male, Mage = 13.98). Actor-Partner Interdependence Models indicated that adolescent males' (but not females') exposure to violent games positively predicted the aggression of their best friend 1 year later. This effect appeared regardless of whether the friends played video games together or not. The study illustrates the importance of peers in the association between violent gaming and aggression.

Video Gaming and Children's Psychosocial Wellbeing: A Longitudinal Study.

The effects of video games on children's psychosocial development remain the focus of debate. At two timepoints, 1 year apart, 194 children (7.27-11.43 years old; male = 98) reported their gaming frequency, and their tendencies to play violent video games, and to game (a) cooperatively and (b) competitively; likewise, parents reported their children's psychosocial health. Gaming at time one was associated with increases in emotion problems. Violent gaming was not associated with psychosocial changes. Cooperative gaming was not associated with changes in prosocial behavior. Finally, competitive gaming was associated with decreases in prosocial behavior, but only among children who played video games with high frequency. Thus, gaming frequency was related to increases in internalizing but not externalizing, attention, or peer problems, violent gaming was not associated with increases in externalizing problems, and for children playing approximately 8 h or more per week, frequent competitive gaming may be a risk factor for decreasing prosocial behavior. We argue that replication is needed and that future research should better distinguish between different forms of gaming for more nuanced and generalizable insight.

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).

Behavioral Correlates of Prioritizing Popularity in Adolescence.

Little is known about individual differences in adolescents' motivation to achieve and maintain popularity. This study examined the moderating effects of prioritizing popularity on the associations between popularity and adjustment outcomes in late adolescence. Participants were 314 Dutch eleventh-grade students (M age = 16.83 years; 52 % male) who completed measures of popularity, prioritizing popularity, and prosocial, antisocial, and risk behaviors. It was hypothesized that associations between popularity and adjustment outcomes are stronger for adolescents who prioritize popularity. The results indicate that the combination of being popular and valuing popularity was strongly related to antisocial and risk behaviors, but not to prosocial behaviors. Adolescents' social status motivations thus play an important role in the association of popularity with antisocial and risk behaviors in late adolescence.

Prospective relationships between sleep problems and substance use, internalizing and externalizing problems.

While research has shown that sleep problems and substance use are reciprocally associated in adults, much less is known about this association in early adolescence. The main aim of the current longitudinal study was to explore bidirectional relationships between sleep problems, substance use, internalizing and externalizing problems in young adolescents. A prospective design was used incorporating two waves (approximately 1 year interval). A total of 555 young adolescents (290 females, M age = 13.96) participated in this study. All participants completed self-report measures in classrooms during regular school hours (questionnaires about sleep quality and sleep hygiene were used to measure sleep problems). The results indicated that sleep problems predicted changes in substance use, internalizing and externalizing problems over time, but problem behaviours did not predict changes in sleep problems, adjusted for gender, age and puberty. One exception was that alcohol use negatively predicted changes in sleep problems. This study suggests that sleep problems are important precursors of substance use, internalizing and externalizing problems in adolescence.

Divergence in self- and peer-reported victimization and its association to concurrent and prospective adjustment.

Previous studies on victimization have either used self-reports of peer-reports, but correspondence between these measures is low, implying that types of victims may exist that differ in convergence between self- and peer-reported victimization. Importantly, the very few studies that do exist on such types were cross-sectional, and did not address the stability nor predictive validity in terms of adjustment of these types. Using a person-centered approach, the present study identified types of victims that were either convergent or divergent in self- and peer-reported victimization, and examined how these types differed in concurrent and prospective adjustment. Participants were 1,346 adolescents (50 % girls, mean age 14.2) who were followed for 1 year. Using Latent Profile Analysis, we identified two convergent types (self-peer identified victims and non-victims) and two divergent types (self-identified and peer-identified) of victims. The types were highly stable over time. Self-peer identified victims were not only concurrently but also prospectively the least well adjusted. Self-identified victims showed lower levels of emotional adjustment but did not show problems on social adjustment. On the other hand, peer-identified victims were at risk for social but not emotional maladjustment. The findings corroborate previous studies that suggest that self-reported victimization is related to emotional problems, while peer-reported victimization is more indicative of social problems. The findings also suggest that using self-reports or peer-reports only may lead to incomplete conclusions about victims' adjustment on different domains.