Peer Influence, Friend Selection, and Gender: How Network Processes Shape Adolescent Smoking, Drinking, And Delinquency

Influence of perceived peer behavior on engagement in self-damaging behaviors during the transition to university

As students transition to university, they experience significant social changes that can affect their behaviors, including self-damaging behaviors like disordered eating, problematic alcohol/drug use, suicidal thoughts, and non-suicidal self-injury (NSSI). Building on prior work, we examined the associations between (1) perceptions of peers' engagement in self-damaging behaviors predicting one's own subsequent engagement in such behaviors (i.e., socialization) and (2) one's own engagement in self-damaging behaviors predicting perceptions of peers' subsequent engagement in such behaviors (i.e., selection). We also examined whether these associations were moderated by the source of influence (close peer/acquaintance) and degree of social disconnection experienced by the student. First-year university students (N = 704) were asked to complete seven monthly surveys. Multilevel models indicated that when students perceived their close peers had engaged in NSSI or suicidal thinking, they had seven times greater odds of future engagement in the same behavior, implying that socialization increases the risk of these behaviors among university students. Perception of acquaintances' NSSI also predicted greater odds of a student's own NSSI the following month. Social disconnection increased the likelihood of matching own behaviors to perceptions of acquaintances' alcohol abuse, highlighting the importance of fostering connections/mentors to reduce self-damaging behaviors on college campuses. Furthermore, when students engaged in alcohol abuse, they had almost four times greater odds of reporting that their acquaintances abused alcohol the following month, emphasizing the importance of the wider social network in alcohol use behaviors.

The association between parental cardiovascular health status and the risk of obesity in their offspring: Tehran Lipid and Glucose Study

BACKGROUND AND AIMS

Little is known about the association of parental cardiovascular risk factors with the risk of obesity in offspring. We aimed to investigate whether parental ideal cardiovascular health (ICVH) status was associated with the risk of general and central obesity in their young/adult offspring.

METHODS AND RESULTS

Of individuals who participated in the 2012-15 phase of the Tehran Lipid and Glucose Study, 2395 pairs of parent-unmarried offspring aged ≥6 years were selected in this cross-sectional study. General and central obesity were defined based on Iranian BMI percentile reference data for offspring aged ≤18 years. For subjects aged ≥19 years, central obesity was defined based on the introduced cut-off points for Iranian adults. We employed the American Heart Association's 2020 impact goal criteria of ICVH. The mean ± SD age of fathers and mothers were respectively 55.4 ± 9.79 and 48.4 ± 9.88. About 55% of offspring were older than 19 years. Higher adherence to ICVH score in mothers was associated with lower risk of overweight/obesity in female offspring (OR for Q1-Q4: 1, 0.56, 0.57, 0.37, P < 0.05 for all quartiles). Among ICVH components, only ideal BMI status in fathers was observed to be associated with a lower risk of overweight/obesity in their male offspring. The risk of abdominal obesity decreased in female offspring with increasing total ICVH score in mothers.

CONCLUSION

Higher adherence of parents to ICVH and its components was positively associated with a lower risk of general and abdominal obesity in their offspring. Our findings demonstrate that maternal-offspring relationship was stronger than paternal-offspring association.

Does cognitive control mediate the relationship between peer presence and adolescent risk-taking? An ERP study

Peer presence influences risk-taking behavior, particularly in adolescence. Based on the dual system model, this event-related potential study examined whether and how the presence of a peer displayed a preference for risky behavior would increase adolescents' risk-taking by disrupting their cognitive control processes in either emotional or non-emotional contexts. A sample of 106 adolescents (17-19 years of age) completed two Stoop tasks and a Balloon Analog Risk Task under three peer presence conditions. Results revealed that compared to other conditions, the presence of a risk-averse peer caused adolescents to make safer decisions through improving their conflict monitoring (more negative N200-diff), whereas a risk-preference peer's presence led adolescents to more risky decisions through disrupting their conflict resolution (more positive N450-diff) but they were only observed on the Emotional Stroop task. These findings suggest that different peer presence contexts could increase or decrease adolescents' risk-taking behaviors by influencing their cognitive control under an emotional context rather than in a non-emotional context.

The Social Processes of Excessive Online Gaming Homophily: Peer Selection or Influence?

Adolescents who befriend online game using peers may be at risk for initiated and continued excessive game use (online gaming use homophily). The present article examined how adolescents' severity of online gaming use related to their friends' online gaming behavior bi-directionally across a semester (peer selection or peer influence effect). Students from two universities completed three waves of online surveys within four and a half months (N = 3079; 33.6% female; Mage = 19.16; SD = 0.97). Random-intercepts, Cross-Lagged Panel Model (RI-CLPM) analyses revealed that peer selection and peer influence both promote online gaming use homophily in adolescents' friendship groups. Furthermore, participants were more likely to form new friendships with peers exhibiting similar online gaming behavior as their behavior, subsequently reinforcing their online gaming use behaviors within these relationships. These social processes may exhibit a time lag among girls, which needs to be confirmed through longer-term follow-up. In general, findings suggest that effective prevention programs targeting excessive online gaming should not only focus on promoting social influence skills but also consider the structure of peer environments.

Susceptibility to e-cigarette adoption among tobacco-naïve youths: a cross-sectional study in Shenzhen, China

Background

The rise in e-cigarette use among youth is a significant global public health issue. It is important to identify those at increased risk and implement effective strategies to reduce e-cigarette popularity among the youth.

Objective

This study aims to identify predictors of e-cigarette uptake in youths with no prior tobacco use, considering individual, familial and the broader societal environmental factors.

Methods

For this investigation, a group of 2,487 tobacco-free youths was selected from 15 high schools in Shenzhen, China. Susceptibility to e-cigarettes was determined by assessing the possibility of future use and the openness to trying e-cigarettes if presented by friends. Both chi-square tests and logistic regression were applied to identify factors linked to susceptibility to e-cigarette use.

Results

Among the respondents, 5.5% (n = 136) were found to be susceptible to e-cigarette use. The analysis revealed factors tied to this risk: perceptions of e-cigarettes, the impact of vaping peers, paternal parenting styles, the extent of social support, exposure to messages both for and against e-cigarettes use, and secondhand smoke (SHS) exposure. Youths who downplayed the addictive nature of e-cigarettes (aOR = 2.01; 95% CI: 1.14-3.55; p = 0.016), those with friends who engaged in vaping (aOR = 3.43-7.64; 95%CI: 2.36-20.42; p < 0.001), those experiencing over-protective or rejective maternal parenting (aOR = 1.68-3.01; 95%CI: 1.11-5.77; p = 0.001-0.014) or rejective paternal parenting (aOR = 3.63; 95%CI: 1.99-6.59; p < 0.001), those aware of e-cigarette advertisements (aOR = 1.82; 95%CI: 1.28-2.60; p = 0.001), and those exposed to SHS at home (aOR = 1.68; 95%CI: 1.17-2.41; p = 0.005) or at public places (aOR = 1.72-1.79; 95%CI: 1.21-2.57; p = 0.002-0.003) were more prone to e-cigarettes. In contrast, youths who believed using e-cigarettes reduces one's attractiveness (aOR = 0.34; 95%CI: 0.16-0.72; p = 0.005) or perceived that vaping made social interactions less enjoyable (aOR = 0.26; 95%CI: 0.12-0.58; p = 0.001), those who benefited from high social support (aOR = 0.30-0.60; 95%CI: 0.17-0.97; p < 0.001), and those who noticed message about e-cigarettes' adverse consequence (aOR = 0.54; 95%CI: 0.38-0.77; p = 0.001) were less likely to be inclined toward e-cigarette use.

Conclusion

The propensity of the youth to e-cigarette usage is shaped by a multiple element. An all-encompassing strategy that addresses the individual, familial, and the broader societal aspects is imperative for the effective prevention of e-cigarette initiation among youth.

Dynamic social network analysis of a brief alcohol intervention trial in heavy-drinking college students shows spillover effects

BACKGROUND

Heavy-drinking college students tend to have close social networks, and there is theoretical and empirical support for the idea that behavior change can spread through those networks via close ties. The objective of this research was to determine whether intervention-induced behavior change in a subset of heavy drinkers in a sociometric (whole) college class-year social network is transmitted to other heavy drinkers in the network, resulting in reduced behavioral risk and change in network ties.

METHODS

We conducted a controlled trial in which most of a first-year college class (N = 1236; 56.9% female) was enrolled, with alcohol use and social network ties measured early in each of three semesters. Following a baseline assessment, the network was divided into two groups, brief motivational intervention (BMI) and natural history control (NHC) according to dormitory residence location. A subset of heavy drinkers in each group was selected, and those in the BMI group received an in-person intervention.

RESULTS

Using stochastic actor-oriented modeling, we found a significant tendency for participants in the BMI group to shed ties with individuals with similar drinking behaviors between the first and second semesters, relative to the NHC group. Furthermore, heavy drinkers with reciprocal ties to intervention recipients in the BMI group showed a significant reduction in drinks per week.

CONCLUSIONS

Individual alcohol interventions appear to have effects both on behavior and network connections among individuals who did not receive the intervention. Continued research is needed to identify the optimal conditions for the diffusion of behavior change.

Adolescent smoking patterns: Associations with sociodemographic factors, cyberbullying, and psychiatric diagnoses in an outpatient clinical sample

There is a scarcity of research on smoking in adolescents within a clinical (outpatient) sample, and there is no existing knowledge on the relationship between cyberbullying and smoking in this population. The primary aim of this study is to determine the prevalence of smoking among adolescents in a clinical sample. Additionally, it aims to examine the potential associations between smoking status and factors such as socioeconomic characteristics, psychiatric diagnoses, and cyberbullying levels. A cross-sectional study was performed on 200 adolescents who visited a tertiary child and adolescent psychiatry outpatient clinic. Participants were assessed using the DSM-5 based psychiatric evaluation, the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version-DSM-5 Turkish Adaptation (K-SADS-PL-DSM-5-T), the Revised Cyber Bullying Inventory-II, and the Fagerström Test for Nicotine Dependence. The study found that 21% of the sample consisted of regular smokers, with a higher prevalence observed among older adolescents. The prevalence of depression and disruptive behavior disorders was significantly greater in the smoking group compared to other groups (p:0.043, p < 0.001, respectively). There was a significant difference in the scores for the cyberbullying bully subdimension among smokers (p = 0.013). The results of the multinomial logistic regression analysis indicated significant associations between smoking and age, maternal smoking status, friends smoking status, and a diagnosis of disruptive behavior disorder (p < 0.05 for all variables). This study reveals a significant prevalence of adolescent smoking in an outpatient clinic. These findings highlight the necessity of implementing focused smoking cessation interventions for this specific population.

The coevolution of bullying and friendship networks

The coevolution of bullying and friendship networks and the moderating effects of classroom bullying popularity norms were examined in a sample of 965 students (52.1% boys) in 22 fourth- and fifth-grade classes. Longitudinal social network analysis showed that children were more likely to bully their friends' victims (bully influence effect) and to be bullied by their friends' bullies (victim influence effect); two children bullying the same child were likely to be friends (bully selection effect), and two victims bullied by the same child were likely to be friends (victim selection effect). Bullying popularity norms served as moderators, and the bully selection effect was significant weaker in the context of low bullying popularity norms. This study adds understanding of bullying as a group process and provides implications for preventing school bullying.

The long-term effectiveness and cost-effectiveness of public health interventions; how can we model behavior? A review

The effectiveness and cost of a public health intervention is dependent on complex human behaviors, yet health economic models typically make simplified assumptions about behavior, based on little theory or evidence. This paper reviews existing methods across disciplines for incorporating behavior within simulation models, to explore what methods could be used within health economic models and to highlight areas for further research. This may lead to better-informed model predictions. The most promising methods identified which could be used to improve modeling of the causal pathways of behavior-change interventions include econometric analyses, structural equation models, data mining and agent-based modeling; the latter of which has the advantage of being able to incorporate the non-linear, dynamic influences on behavior, including social and spatial networks. Twenty-two studies were identified which quantify behavioral theories within simulation models. These studies highlight the importance of combining individual decision making and interactions with the environment and demonstrate the importance of social norms in determining behavior. However, there are many theoretical and practical limitations of quantifying behavioral theory. Further research is needed about the use of agent-based models for health economic modeling, and the potential use of behavior maintenance theories and data mining.

Developmental Changes in Habenular and Striatal Social Reinforcement Responsivity Across Adolescence Linked With Substance Use

BACKGROUND

Habenula (HB) function is implicated in substance use disorders and is involved in inhibiting dopamine release in the ventral striatum (VS). While blunted VS reward responsivity is implicated in risk for later substance use, links between HB reinforcement processing and progression of use have not, to our knowledge, been examined among adolescents. In the present study, we longitudinally assessed HB and VS responsivity to social rewards and punishments across adolescence and examined associations with substance use.

METHODS

Within a longitudinal design, 170 adolescents (53.5% female) completed 1 to 3 functional magnetic resonance imaging scans across 6th to 9th grade and reported yearly substance use across 6th to 11th grade. We examined VS and HB responsivity to social reinforcement during a social incentive delay task in which adolescents received social rewards (smiling faces) and punishments (scowling faces).

RESULTS

We observed increased VS responsivity to social rewards (vs. reward omissions) and increased VS, but decreased HB, responsivity to social punishment avoidance versus receipt. However, contrary to hypotheses, the HB displayed increased responsivity to social rewards (vs. reward omissions). Further, adolescents reporting regular substance use displayed longitudinally declining HB responsivity to social rewards (vs. reward omissions), whereas adolescents reporting no substance use displayed longitudinally increasing HB responsivity. In contrast, whereas VS responsivity to punishment avoidance versus receipt increased longitudinally among regular substance users, it stayed relatively stable among nonusers.

CONCLUSIONS

These results suggest that differential HB and VS social reinforcement processing trajectories across adolescence are associated with substance use.

The cost of social influence: Own-gender and gender-stereotype social learning biases in adolescents and adults

Pervasive gender gaps in academic subject and career choices are likely to be underpinned by social influences, including gender stereotypes of competence in academic and career domains (e.g., men excel at engineering, women excel at care), and model-based social learning biases (i.e., selective copying of particular individuals). Here, we explore the influence of gender stereotypes on social learning decisions in adolescent and adult males and females. Participants (Exp 1: N = 69 adolescents; Exp 2: N = 265 adults) were presented with 16 difficult multiple-choice questions from stereotypically feminine (e.g., care) and masculine (e.g., engineering) domains. The answer choices included the correct response and three incorrect responses paired with a male model, a female model, or no model. Participants' gender stereotype knowledge and endorsement were measured, and adolescents (Exp. 1) listed their academic subject choices. As predicted, there was a bias towards copying answers paired with a model (Exp.1: 74%, Exp. 2: 65% ps < .001). This resulted in less success than would be expected by chance (Exp. 1: 12%, Exp. 2: 16% ps < .001), demonstrating a negative consequence of social information. Adults (Exp 2) showed gender stereotyped social learning biases; they were more likely to copy a male model in masculine questions and a female model in feminine questions (p = .012). However, adolescents (Exp 1) showed no evidence of this stereotype bias; rather, there was a tendency for male adolescents to copy male models regardless of domain (p = .004). This own-gender bias was not apparent in female adolescents. In Exp 1, endorsement of masculine stereotypes was positively associated with selecting more own-gender typical academic subjects at school and copying significantly more male models in the male questions. The current study provides evidence for the first time that decision-making in both adolescence and adulthood is impacted by gender biases.

Risk and protective factors of social networks on alcohol, cannabis, and opioid use among urban American Indian/Alaska Native emerging adults

OBJECTIVES

Assess associations between social networks and urban American Indian/Alaska Native emerging adults' alcohol, cannabis, and opioid use and intentions.

METHOD

American Indian/Alaska Native participants ages 18-25 (N = 150; 86% female) were recruited across the United States from 12/20 to 10/21 via social media. Participants named up to 15 people whom they talked with most over the past 3 months and reported who (a) used alcohol and cannabis heavily or used other drugs (e.g., opioid use), (b) engaged in traditional practices, and (c) provided support. They also reported past 3-month alcohol, cannabis, and opioid use and intentions to use.

RESULTS

Having a higher proportion of network members engaging in regular cannabis and heavy alcohol use (but not other drugs) was associated with more frequent cannabis use and stronger cannabis use intentions. Participants with higher proportions of members engaging in heavy alcohol use, regular cannabis use, or other drug use and who did not engage in traditional practices were more likely to report cannabis use and greater intentions to use cannabis and drink alcohol. In contrast, participants with higher proportions of network members engaging in traditional practices and who did not report heavy alcohol use, regular cannabis use, or other drug use were less likely to report intentions to use cannabis or drink alcohol.

CONCLUSIONS

Findings emphasize what many studies have shown among various racial/ethnic groups-having network members who use substances increases the chance of use. Findings also highlight that traditional practices may be an important part of the prevention approach for this population. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Age of Smoking Initiation in Relation to Multiple Health Risk Factors among US Adult Smokers: National Health Interview Survey (NHIS) Data (2006-2018)

The adverse effects of multiple health risk factors have been well-documented; however, still understudied are the effects of early smoking in the context of multiple health risk factors. This study aimed to examine the role of early smoking initiation in relation to several health risk factors, including heavy drinking, physical inactivity, and obesity in later life among ever smokers in the USA. The National Health Interview Survey (NHIS) data from 2006 through 2018 were analyzed. The primary dependent variables were presence of three other risk factors: heavy drinking, physical inactivity, and obesity. The independent variable was the age of smoking initiation. Logit regression models were constructed to evaluate the association between smoking initiation and multiple health risk factors. All analyses were done in 2022. Among US adult smokers, 18.2% started smoking before age 15 (early initiators), 55.9% at ages 15-18 (middle initiators), and 25.9% at age 20 or later (late initiators). Compared to late smoking initiators, the odds of engaging in additional health risk factors increased by 37.3% among early initiators (OR = 1.373, 95% CI = 1.316, 1.432) and 7.7% among middle initiators (OR = 1.077, 95% CI= 1.041, 1.116). Additionally, current smoking was associated with higher odds (OR = 1.369, 95% CI = 1.322, 1.417) of having additional health risk factors compared to former smoking, with one exception: current smokers had lower odds of obesity (OR = 0.566, 95% CI = 0.537, 0.597). Tobacco control programs to prevent adolescents from initiating smoking may have the potential to prevent other health risk factors in adulthood.

A Systematic Review of Systems Science Approaches to Understand and Address Domestic and Gender-Based Violence

Purpose

We aimed to synthesize insights from systems science approaches applied to domestic and gender-based violence.

Methods

We conducted a systematic review of systems science studies (systems thinking, group model-building, agent-based modeling [ABM], system dynamics [SD] modeling, social network analysis [SNA], and network analysis [NA]) applied to domestic or gender-based violence, including victimization, perpetration, prevention, and community responses. We used blinded review to identify papers meeting our inclusion criteria (i.e., peer-reviewed journal article or published book chapter that described a systems science approach to domestic or gender-based violence, broadly defined) and assessed the quality and transparency of each study.

Results

Our search yielded 1,841 studies, and 74 studies met our inclusion criteria (45 SNA, 12 NA, 8 ABM, and 3 SD). Although research aims varied across study types, the included studies highlighted social network influences on risks for domestic violence, clustering of risk factors and violence experiences, and potential targets for intervention. We assessed the quality of the included studies as moderate, though only a minority adhered to best practices in model development and dissemination, including stakeholder engagement and sharing of model code.

Conclusions

Systems science approaches for the study of domestic and gender-based violence have shed light on the complex processes that characterize domestic violence and its broader context. Future research in this area should include greater dialogue between different types of systems science approaches, consideration of peer and family influences in the same models, and expanded use of best practices, including continued engagement of community stakeholders.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10896-023-00578-8.

Leadership and contagion by COVID-19 among residence hall students: A social network analysis approach

University students have changed their behaviour due to the COVID-19 pandemic. In this paper, we describe the characteristics of PCR+ and PCR- nodes, analyse the structure, and relate the structure of student leaders to pandemic contagion as determined by PCR+ in 93 residential university students. Leadership comes from the male students of social science degrees who have PCR +, with an eigenvector centrality structure, β-centrality, and who are part of the bow-tie structure. There was a significant difference in β-centrality between leaders and non-leaders and in β-centrality between PCR+ and non-leaders. Leading nodes were part of the bow-tie structure. MR-QAP results show how residence and scientific branch were the most important factors in network formation. Therefore, university leaders should consider influential leaders, as they are vectors for disseminating both positive and negative outcomes.

Embedded Distress: Social Integration, Gender, and Adolescent Depression

In adolescence, teens manage close friendships while simultaneously evaluating their social position in the larger peer context. Conceptualizing distinct local and global network structures clarifies how social integration relates to mental wellbeing. Examining local cohesion and global embeddedness in the context of key factors related to mental health, such as gender and friends' depression, can further distinguish when the structure and content of social integration relate to higher and lower depressive levels. Analyses using survey data from PROSPER (n = 27,091, grades 9-12) indicate global embeddedness is generally protective, but for girls, greater global embeddedness when friends are more depressive is associated with increased depressive symptoms. For girls, greater local cohesion reduces associations between more depressive friends and increased depressive levels, while for boys, both local cohesion and friends' depression are largely irrelevant. Results indicate the importance of considering both local and global network integration in tandem with gender and friends' depression to understand how social integration relates to mental health.

Prevalence and Associated Factors of E-Cigarette Use among Adolescents in Southeast Asia: A Systematic Review

The use of e-cigarettes in adolescents remains a major public health concern. Like other tobacco products, e-cigarettes pose health risks to adolescents. Understanding the magnitude of this problem and identification of its associated factors will serve as a guide for development of preventive interventions. This systematic review aims to identify and discuss current epidemiological data on the prevalence and associated factors of e-cigarette use among adolescents in Southeast Asia. The reporting of this systematic review is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. We carried out a literature search through three databases (Scopus, PubMed, Web of Science) and targeted original English-language articles published between 2012 and 2021. A total of 10 studies were included in this review. The prevalence of current e-cigarette uses ranges from 3.3% to 11.8%. Several associated factors of e-cigarette use were identified, including sociodemographic factors, traumatic childhood experience, peer and parental influence, knowledge and perception, substance use, and accessibility of e-cigarettes. These factors should be addressed though multifaceted interventions which simultaneously target multiple factors. Laws, policies, programs, and interventions must be strengthened and tailored to the needs of adolescents at risk of using e-cigarettes.

Changing contexts: A quasi-experiment examining adolescent delinquency and the transition to high school

In a quasi-experiment, we examine whether changing schools during the transition from 8th to 9th grade influences adolescent delinquency, using a sample of more than 14,000 students in 26 public school districts (PROSPER study). The dataset follows students for eight waves from 6th through 12th grade and facilitates a unique, direct comparison of students who change schools with those who remain in the same school during this period. Results show that students who transition between schools report significantly less delinquency after the shift than those who do not, and that this difference persists through 10th grade. This decline is most pronounced when adolescents from multiple middle schools move to a single high school (i.e., multifeeder transitions). Students who transition between schools have fewer delinquent friends and participate in less unstructured socializing following the change in school environment, which partially mediates their reduced delinquency. Results provide some support for theories of differential association and routine activities. Our findings highlight the role of a crucial, yet understudied, life transition in shaping adolescent delinquency. The results from this quasi-experiment underscore the potential of alterations in social context to significantly dampen juvenile delinquency throughout high school.

Social network correlates of free and purchased insecticide-treated bed nets in rural Uganda

BACKGROUND

Malaria is a major cause of mortality and morbidity in Uganda. Despite Uganda's efforts to distribute bed nets, only half of households have achieved the World Health Organization (WHO) Universal Coverage Criteria (one bed net for every two household members). The role of peer influence on bed net ownership remains underexplored. Data on the complete social network of households were collected in a rural parish in southwestern Uganda to estimate the association between household bed net ownership and peer household bed net ownership.

METHODS

Data on household sociodemographics, bed net ownership, and social networks were collected from all households across one parish in southwestern Uganda. Bed nets were categorized as either purchased or free. Purchased and free bed net ownership ratios were calculated based on the WHO Universal Coverage Criteria. Using network name generators and complete census of parish residents, the complete social network of households in the parish was generated. Linear regression models that account for network autocorrelation were fitted to estimate the association between households' bed net ownership ratios and bed net ownership ratios of network peer households, adjusting for sociodemographics and network centrality.

RESULTS

One thousand seven hundred forty-seven respondents were interviewed, accounting for 716 households. The median number of peer households to which a household was directly connected was 7. Eighty-six percent of households owned at least one bed net, and 41% of households met the WHO Universal Coverage Criterion. The median bed net ownership ratios were 0.67 for all bed nets, 0.33 for free bed nets, and 0.20 for purchased bed nets. In adjusted multivariable models, purchased bed net ownership ratio was associated with average household wealth among peer households (b = 0.06, 95% CI 0.03, 0.10), but not associated with average purchased bed net ownership ratio of peer households. Free bed net ownership ratio was associated with the number of children under 5 (b = 0.08, 95% CI 0.05, 0.10) and average free bed net ownership ratios of peer households (b = 0.66, 95% CI 0.46, 0.85).

CONCLUSIONS

Household bed net ownership was associated with bed net ownership of peer households for free bed nets, but not for purchased bed nets. The findings suggest that public health interventions may consider leveraging social networks as tools for dissemination, particularly for bed nets that are provided free of charge.

Social determinants of smoking among school adolescents in Beijing, China

INTRODUCTION

Understanding the social determinants that influence adolescent smoking behavior has a meaningful impact on adolescent health. Few studies have simultaneously analyzed the impact of teacher smoking and peer smoking on adolescent smoking. Therefore, the present study aims to investigate the impact of teacher smoking, peer smoking, and other social factors, on adolescent smoking.

METHODS

The participants were drawn from schools in Beijing, China, in 2011, 2013, and 2015, using a multi-stage random group sampling method. The number of schools selected for each year was 160. The study participants were 57240 adolescents aged 8-19 years. The generalized linear model with a binomial distribution and logarithmic link function was used to estimate the influence of social determinants on adolescent smoking behavior.

RESULTS

The results show that both teacher smoking and peer smoking were significantly associated with adolescent smoking. Compared to adolescents whose teachers did not smoke, the prevalence ratio (PR) was 1.28 for adolescents with one teacher who smoked and 1.34 for adolescents with two or more teachers who smoked (95% CI: 1.16-1.41/1.23-1.46, p<0.001/0.001, respectively). Compared to adolescents whose peers did not smoke, the prevalence ratio (PR) was 3.73 for adolescents with one peer who smoked and 8.52 for adolescents with two or more peers who smoked (95% CI: 3.20-4.35/7.48-9.69, p<0.001/0.001, respectively).

CONCLUSIONS

Teacher smoking and peer smoking are significant social determinants of adolescent smoking. Prevention programs should concurrently target peer groups, school settings, and individual students.

Heterogeneous Impact of Social Integration on the Health of Rural-to-Urban Migrants in China

BACKGROUND

While several studies have found that lower levels of social integration may lead to a deterioration in the health status of migrants, previous research on the nexus between social integration and health has generally ignored the potential endogeneity of social integration. This paper examines the heterogeneous impact of social integration on the health of rural-to-urban migrants in China by exploiting plausibly exogenous, long-term, geographic variation in dialectal diversity.

METHODS

Drawing on nationally representative data from the 2017 China Migrants Dynamic Survey (n = 117,446), we first regressed self-reported health on social integration using ordinary least squares estimation and then used an ordered probit model as a robustness check. Additionally, to rule out the potential endogeneity of social integration, we relied mainly on an instrumental variable approach and used dialectal diversity as a source of exogenous variation for social integration.

RESULTS

We found that social integration has a significant positive impact on rural-to-urban migrants' health. We also detected considerable heterogeneity in the effects of social integration across gender, generation, and wage levels: the health status of women, more recent generation migrants, and migrants with wages in the middle of wage distribution are more likely to be affected by social integration.

CONCLUSIONS

We confirmed the beneficial impact of social integration on migrants' health, which has some important policy implications. Successful migration policies should take the fundamental issue of migrants' social integration into account.

Understanding the Roles of Sport and Alcohol Use in Adolescence on Physical and Sexual Intimate Partner Violence Perpetration in Young Adulthood: Findings From a Sex-Stratified Multilevel Analysis

Adolescent peer groups shape beliefs that dictate behavioral norms, including intimate partner violence (IPV) perpetration behaviors, with lasting influence into adulthood. This study examines the role of sport engagement and alcohol use in adolescence on perpetration of physical and sexual IPV in young adulthood. A secondary data analysis was conducted with data from 3411 male and 4318 female participants in the National Longitudinal Study of Adolescent to Adult Health study. Sports and other school activity participation, as well as alcohol use, were measured in middle and high school students. Intimate partner violence perpetration was measured six years later with items from the revised Conflict Tactics Scales. Sex-stratified logistic cross-classified multilevel analyses indicate that, for males, participation in football in adolescence was associated with higher odds of IPV perpetration in young adulthood (aOR:1.26, p = .01). For males and females, non-engagement in any school activities in adolescence was associated with higher odds of IPV perpetration in young adulthood (male aOR: 1.52, p < .01; female aOR: 1.19, p = .04). Alcohol use in adolescence was also associated with higher odds of IPV perpetration in young adulthood for both males and females, even when low level drinking (1-2 drinks in the past 12 months) was reported (male aOR: 1.40, p < .01; female aOR: 1.38, p < .01). Random-effect estimates indicate small but significant contributions of adolescent peer, school, and neighborhood contexts on IPV perpetration in young adulthood for both boys and girls. These findings highlight that football engagement among boys, and alcohol use among boys and girls, are linked to longer-term risk for IPV perpetration, but engagement in other sports and school activities appear to serve as protective factors. These findings, taken with those regarding social context effects, suggest that positive social environment and networks in adolescence, inclusive of those offered in some sports, can be useful platforms for IPV prevention efforts.

Within-person Changes in Co-rumination and Rumination in Adolescence: Examining Heterogeneity and the Moderating Roles of Gender and Time

Although previous work has consistently identified positive associations between co-rumination and rumination during adolescence, little to no research has examined how this relationship operates on the person-specific level. The current study aimed to extend current developmental theories of co-rumination and rumination by examining within-person associations between these constructs. Survey data was collected from 1502 adolescents (M_age = 13.20; 52% girls; 52% non-Hispanic White) every six-months across the span of 3.5 years. The results showed that at time-points when adolescents reported co-ruminating more than their usual level, they reported concurrent increases in rumination. This association was stronger for boys and strengthened over time. Despite substantial between-person heterogeneity, 97% of adolescents showed positive associations between co-rumination and rumination. This research has important implications for mental health professionals, school systems, and parents who may look to teach adolescents about effective emotion-regulation.

Analytic Advances in Social Networks and Health in the Twenty-First Century

The study of social networks is increasingly central to health research for medical sociologists and scholars in other fields. Here, we review the innovations in theory, substance, data collection, and methodology that have propelled the study of social networks and health from a niche subfield to the center of larger sociological and scientific debates. In particular, we contextualize the broader history of network analysis and its connections to health research, concentrating on work beginning in the late 1990s, much of it in this journal. Using bibliometric and network visualization approaches, we examine the subfield's evolution over this period in terms of topics, trends, key debates, and core insights. We conclude by reflecting on persistent challenges and areas of innovation shaping the study of social networks and health and its intersection with medical sociology in the coming years.

Arrested Friendships? Justice Involvement and Interpersonal Exclusion among Rural Youth

Objectives

We examine the impacts of adolescent arrest on friendship networks. In particular, we extend labeling theory by testing hypotheses for three potential mechanisms of interpersonal exclusion related to the stigma of arrest: rejection, withdrawal, and homophily.

Method

We use longitudinal data on 48 peer networks from PROSPER, a study of rural youth followed through middle and high school. We test our hypotheses using stochastic actor-based models.

Results

Our findings suggest that arrested youth are less likely to receive friendship ties from school peers, and are also less likely to extend them. Moreover, these negative associations are attenuated by higher levels of risky behaviors among peers, suggesting that results are driven by exclusion from normative rather than non-normative friendships. We find evidence of homophily on arrest but it appears to be driven by other selection mechanisms rather than a direct preference for similarity on arrest.

Conclusions

Overall, our findings speak to how arrest may foster social exclusion in rural schools, thereby limiting social capital for already disadvantaged youth.

Exploring the association between school-based peer networks and smoking according to socioeconomic status and tobacco control context: a systematic review

BACKGROUND

Whilst prevalence of youth smoking in middle and high income countries has decreased, inequality has prevailed. The introduction of legislation regulating tobacco use in public spaces varies across countries, impacting the tobacco control context. Thus reviewing our knowledge of how social networks may influence smoking differently within different contexts is required to facilitate the development of context-specific interventions.

METHODS

The search, conducted on 31st May 2019, included the following smoking-related terms; schools, adolescents, peers and social networks. Inclusion and exclusion criteria were applied throughout the title and abstract screening and full text screening. Quality assessment and synthesis followed. Studies were narratively synthesised to identify changes according to legislative context. This synthesis was conducted separately for findings relating to three categories: socioeconomic status; social selection and influence; and network position.

RESULTS

Thirty studies were included. Differences in the relationship between network characteristics and smoking according to socioeconomic status were measured in five out of fifteen studies in Europe. Results varied across studies, with differences in network characteristics and their association with smoking varying both between schools of a differing and those of a similar socioeconomic composition. For studies conducted both before and after the introduction of comprehensive smoking legislation, the evidence for selection processes was more consistent than influence, which varied according to reciprocity. Findings showed that isolates were more likely to smoke and in-degree and out-degree centrality were related to smoking both before and after the introduction of legislation. The relationship between popularity and smoking was contingent on school level smoking prevalence in studies conducted before the introduction of legislation, but not after.

CONCLUSIONS

Overall, effects according to socioeconomic status were underreported in the included studies and no consistent evidence of change after the introduction of a comprehensive smoking ban was observed. Further network analyses are required using more recent data to obtain a comprehensive understanding of how network processes may influence smoking differently according to socioeconomic status, and how adaptation could be used to enhance intervention effectiveness.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42019137358 .

Worth the Weight: Conceptualizing and Measuring Strong Versus Weak Tie Homophily

Homophily, or the tendency for social contact to occur among those who are similar, plays a crucial role in structuring our social networks. Most previous work considers whether homophily shapes the patterns of all social ties, regardless of their frequency of interaction or level of intimacy. As complex network data become increasingly available, however, researchers need to evaluate whether homophily operates differently for ties defined by strong versus weak measures of strength. Here, I take this approach by first defining two variants of homophily: (1) strong tie homophily, or the tendency for ties with high measures of strength to cluster together similar peers, and (2) weak tie homophily, or the tendency for ties with low edge weights to connect same-attribute actors. Then, I apply valued ERGMs to demonstrate the utility of differentiating between the two variants across simulated and observed networks. In most networks, I find that there are observable differences in the magnitude of strong versus weak tie homophily. Additionally, when there are low levels of clustering on the attribute of interest, distinguishing between strong and weak tie homophily can reveal that these processes operate in opposite directions. Since strong and weak ties carry substantively different implications, I argue that differentiating between the two homophily variants has the potential to uncover novel insights on a variety of social phenomena.

The Relationship Between Smoker Identity and Smoking Cessation Among Young Smokers: The Role of Smoking Rationalization Beliefs and Cultural Value of Guanxi

Although the relationship between smoker identity and smoking cessation behavior has been confirmed, the role of smoking-related beliefs and cultural values in this relationship for young smokers is little known. The present study aimed to examine whether the relationship between smoker identity and smoking cessation behavior would be mediated by smoking rationalization beliefs and/or intention to quit smoking and whether the effect of smoker identity on smoking cessation behavior was moderated by cultural value of guanxi. A total of 708 young smokers participated in the study and completed questionnaires that measured smoker identity, smoking rationalization beliefs, intention to quit smoking, smoking cessation behavior and cultural value of guanxi. The results showed: (1) the relationship between smoker identity and smoking cessation behavior was negative and significant. (2) The mediating effect of intention to quit smoking and the serial mediating effect of "smoking rationalization beliefs → intention to quit smoking" on the relationship between smoker identity and smoking cessation behavior was significant. (3) Both the serial mediating effect of "smoking rationalization beliefs → intention to quit smoking" and the direct effect of smoker identity on smoking cessation behavior were moderated by cultural value of guanxi. The current findings increased understanding of psychosocial mechanisms underlying the hindering effect of smoker identity on smoking cessation and suggested the role of smoking rationalization beliefs and cultural value of guanxi should be considered in smoking cessation interventions for young smokers.

Toward understanding the functions of peer influence: A summary and synthesis of recent empirical research

Compelling evidence demonstrates that peer influence is a pervasive force during adolescence, one that shapes adaptive and maladaptive attitudes and behaviors. This literature review focuses on factors that make adolescence a period of special vulnerability to peer influence. Herein, we advance the Influence-Compatibility Model, which integrates converging views about early adolescence as a period of increased conformity with evidence that peer influence functions to increase affiliate similarity. Together, these developmental forces smooth the establishment of friendships and integration into the peer group, promote interpersonal and intragroup compatibility, and eliminate differences that might result in social exclusion.

Social Contact Reinforces Cocaine Self-Administration in Young Adult Male Rats: The Role of Social Reinforcement in Vulnerability to Drug Use

Drug-using peers are recognized as a leading factor influencing drug use among adolescents and young adults. One mechanism by which peers influence drug use is by providing social reinforcement for using drugs. Social reinforcement may be provided in multiple ways, including by making social contact contingent on drug use (i.e., an individual must use drugs to gain/maintain access to a peer). The purpose of this study was to develop a preclinical model in which intravenous cocaine self-administration was positively reinforced by access to a social partner. Young adult male rats were trained to self-administer cocaine in operant conditioning chambers with a guillotine door that could be opened to an adjacent compartment housing either a social partner or a non-social stimulus. Once cocaine self-administration was established, the guillotine door was activated, and cocaine intake was reinforced by brief access to either a social (age- and sex-matched peer) or non-social (black-and-white athletic sock) stimulus. Contingent access to a social partner rapidly increased cocaine self-administration. Total cocaine intake was 2- to 3-fold greater in rats assigned to the social versus non-social condition across a 100-fold dose range. Cocaine intake rapidly increased when rats in the original non-social group were later provided with social partners, whereas cocaine intake resisted change and remained elevated when rats in the original social group had their partners removed. These data indicate that contingent access to a social partner increases drug intake and suggest that social reinforcement may represent a vulnerability factor that is particularly resistant to psychosocial interventions.

Do high school friends still matter for health behavior in adulthood? Variations in smoking trajectories by adolescent peer smoking networks, race/ethnicity, and gender

Peers play an influential role in the initiation of smoking during adolescence. However, there has been limited literature examining whether adolescent peers are associated with longer-term patterns of smoking. This study uses data from the National Longitudinal Study of Adolescent to Adult Health to examine whether age-based trajectories of smoking likelihood from adolescence to adulthood are associated with the number of adolescent friends who smoked and how this association differs by race/ethnicity and gender. Findings using multilevel growth curve models indicate that individuals who have more adolescent friends who smoked have higher probabilities of smoking during adolescence than those with no adolescent smoking friends. As individuals age into adulthood, the association between adolescent friends’ smoking behavior and individual-level smoking begin to dissipate but does not completely disappear. Further analyses show that there are no differences in this association by gender, but there are differences by race/ethnicity. These findings suggest that high school friends continue to be associated with trajectories of smoking even twenty years after high school. These results indicate that anti-smoking campaigns should take a network approach to preventing smoking in adolescence as well as recognize that the same campaign strategy may not work for all groups.

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Adolescent friends are associated with smoking trajectories into adulthood.

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The friends-smoking association wanes with age but does not completely dissipate.

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This friends-smoking association increases with age for Black adults.

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There are no significant differences in the friends-smoking association by gender.

Combined pharmacotherapy and evidence-based psychosocial Cannabis treatment for youth and selection of cannabis-using friends

BACKGROUND

Theoretical models of behavior change argue that youth should decrease their time with cannabis-using friends and increase their time with non-using friends during treatment. Informed by behavior-change models of recovery and socialization and selection peer-influence models, the current study examined whether combining evidence-based psychosocial treatment with adjunctive pharmacotherapy helps youth decrease their affiliations with cannabis-using friends and increase their affiliations with non-using friends during cannabis misuse treatment.

METHODS

Youth ages 15-24 years (51 % male), participated in a double-blind randomized clinical trial that tested the effects of motivational enhancement and cognitive behavioral therapy (MET-CBT) plus topiramate (N = 39) or placebo (N = 26) on cannabis craving and use. Ecological momentary assessment data, collected via smartphones throughout the six-week intervention, assessed youths' time with cannabis-using and non-using friends, cannabis use, and craving in daily life. Multiple group multilevel structural equation modeling tested study hypotheses.

RESULTS

Across the topiramate (48 % completion rate) and placebo (77 % completion rate) conditions, greater time spent with cannabis-using friends promoted greater next day cannabis use and craving (socialization effect). In turn, cannabis craving, but not use, promoted continued selection of cannabis-using friends. This indirect effect was only supported in the placebo condition due to the selection piece of this cycle not being significant for youth who received topiramate. Neither cannabis craving nor use were associated with time with non-using friends the next day.

CONCLUSIONS

MET-CBT and adjunctive topiramate pharmacotherapy interrupted youth selection processes. This finding suggests that changing peer affiliations could be one mechanism by which treatments can work.

A case study of university student networks and the COVID-19 pandemic using a social network analysis approach in halls of residence

The COVID-19 pandemic has meant that young university students have had to adapt their learning and have a reduced relational context. Adversity contexts build models of human behaviour based on relationships. However, there is a lack of studies that analyse the behaviour of university students based on their social structure in the context of a pandemic. This information could be useful in making decisions on how to plan collective responses to adversities. The Social Network Analysis (SNA) method has been chosen to address this structural perspective. The aim of our research is to describe the structural behaviour of students in university residences during the COVID-19 pandemic with a more in-depth analysis of student leaders. A descriptive cross-sectional study was carried out at one Spanish Public University, León, from 23th October 2020 to 20th November 2020. The participation was of 93 students, from four halls of residence. The data were collected from a database created specifically at the university to "track" contacts in the COVID-19 pandemic, SiVeUle. We applied the SNA for the analysis of the data. The leadership on the university residence was measured using centrality measures. The top leaders were analyzed using the Egonetwork and an assessment of the key players. Students with higher social reputations experience higher levels of pandemic contagion in relation to COVID-19 infection. The results were statistically significant between the centrality in the network and the results of the COVID-19 infection. The most leading students showed a high degree of Betweenness, and three students had the key player structure in the network. Networking behaviour of university students in halls of residence could be related to contagion in the COVID-19 pandemic. This could be described on the basis of aspects of similarities between students, and even leaders connecting the cohabitation sub-networks. In this context, Social Network Analysis could be considered as a methodological approach for future network studies in health emergency contexts.

What is(n't) a friend? Dimensions of the friendship concept among adolescents

Much research in network analysis of adolescent friendships assumes that friendships represent liking and social interaction, friendships are directed, and friendships are equivalent to one another. This study investigates the meaning of friendship for eight diverse cohorts of sixth graders. Analysis of focus group and survey data suggests that these adolescents construe friendship as a multidimensional role relation composed primarily of relational norms, expectations for mutual behavior. Their friendship definitions may also include mutual liking and interaction, and other structural expectations such as reciprocity, homophily, and transitivity. Lastly, boys and girls weight these dimensions differently in defining friendship.

Comparing targeting strategies for network-based adolescent drinking interventions: A simulation approach

Public health researchers and social scientists highlight the promise of network-based strategies to inform and enhance interventions that curb risky adolescent health behaviors. However, we currently lack an understanding of how different variants of network-based interventions shape the distribution of targeted behaviors. The current project considers the effectiveness of five targeting strategies that are designed to have differential impacts on the health of program participants versus non-participants. Using simulations that are empirically-grounded in 28 observed school-based networks from the PROSPER study, we evaluate how these approaches shape long-term alcohol use for intervention participants and non-participants, separately, and consider whether contextual factors moderate their success. Findings suggest that enrolling well-connected adolescents results in the lowest drinking levels for non-participants, while strategies that target groups of friends excel at protecting participants from harmful influences. These trends become increasingly pronounced in contexts characterized by higher levels of peer influence.

Social Network Research contribution to evaluating process in a feasibility study of a peer-led and school-based sexual health intervention

There is growing interest in social network-based programmes to improve health, but rigorous methods using Social Network research to evaluate the process of these interventions is less well developed. Using data from the "STis And Sexual Health" (STASH) feasibility trial of a school-based, peer-led intervention on sexual health prevention, we illustrate how network data analysis results can address key components of process evaluations for complex interventions-implementation, mechanisms of impacts, and context. STASH trained students as Peer Supporters (PS) to diffuse sexual health messages though face-to-face interactions and online Facebook (FB) groups. We applied a Multilevel Exponential Random Graph modelling approach to analyse the interdependence between offline friendship relationships and online FB ties and how these different relationships align. Our results suggest that the creation of online FB communities mirrored offline adolescent groups, demonstrating fidelity of intervention delivery. Data on informal friendship networks related to student's individual characteristics (i.e., demographics, sexual health knowledge and adherence to norms, which were included for STASH), contributed to an understanding of the social relational 'building' mechanisms that sustain tie-formation. This knowledge could assist the selection of opinion leaders, improving identification of influential peers situated in optimal network positions. This work provides a novel contribution to understanding how to integrate network research with the process evaluation of a network intervention.

Peer influence in adolescent drinking behavior: A meta-analysis of stochastic actor-based modeling studies

Objectives

To measure the effects of peer influence and peer selection on drinking behavior in adolescence through a rigorous statistical approach designed to unravel these interrelated processes.

Methods

We conducted systematic searches of electronic databases, thesis collections and conference proceedings to identify studies that used longitudinal network design and stochastic actor-oriented modeling to analyze drinking behavior in adolescents. Parameter estimates collected from individual studies were analyzed using multilevel random-effects models.

Results

We identified 26 articles eligible for meta-analysis. Meta-analyses for different specifications of the peer influence effect were conducted separately. The peer influence effect was positive for every specification: for average similarity (avSim) mean log odds ratio was 1.27 with 95% confidence interval [0.04; 2.49]; for total similarity (totSim) 0.46 (95% CI = [0.44; 0.48]), and for average alter (avAlt) 0.70 (95% CI = [-0.01; 1.41]). The peer selection effect (simX) was also positive: 0.46 (95% CI = [0.28; 0.63]). Conversion log odds ratio values to Cohen’s d gives estimates from 0.25 to 0.70, which is considered as medium to large effect.

Conclusions

Advances in methodology for social network analysis have made it possible to accurately estimate peer influence effects free from peer selection effects. More research is necessary to clarify the roles of age, gender, and individual susceptibility on the changing behavior of adolescents under the influence of their peers. Understanding the effects of peer influence should inform practitioners and policy makers to design and deliver more effective prevention programs.

Prevalence and Childhood Precursors of Opioid Use in the Early Decades of Life

IMPORTANCE

Opioid use disorder and opioid deaths have increased dramatically in young adults in the US, but the age-related course or precursors to opioid use among young people are not fully understood.

OBJECTIVE

To document age-related changes in opioid use and study the childhood antecedents of opioid use by age 30 years in 6 domains of childhood risk: sociodemographic characteristics; school or peer problems; parental mental illness, drug problems, or legal involvement; substance use; psychiatric illness; and physical health.

DESIGN, SETTING, AND PARTICIPANTS

This community-representative prospective longitudinal cohort study assessed 1252 non-Hispanic White individuals and American Indian individuals in rural counties in the central Appalachia region of North Carolina from January 1993 to December 2015. Data were analyzed from January 2019 to January 2020.

EXPOSURES

Between ages 9 and 16 years, participants and their parents were interviewed up to 7 times using the Child and Adolescent Psychiatric Assessment and reported risk factors in 6 risk domains.

MAIN OUTCOMES AND MEASURES

Participants were assessed again at ages 19, 21, 25, and 30 years for nonheroin opioid use (any and weekly) and heroin use using the structured Young Adult Psychiatric Assessment.

RESULTS

Of 1252 participants, 342 (27%) were American Indian. By age 30 years, 322 participants had used a nonheroin opioid (24.2%; 95% CI, 21.8-26.5), 155 had used a nonheroin opioid weekly (8.8%; 95% CI, 7.2-10.3), and 95 had used heroin (6.6%; 95% CI, 5.2-7.9). Childhood risk markers for later opioid use included male sex, tobacco use, depression, conduct disorder, cannabis use, having peers exhibiting social deviance, parents with legal involvement, and elevated systemic inflammation. In final models, childhood tobacco use, depression, and cannabis use were most robustly associated with opioid use in young adulthood (ages 19 to 30 years). Chronic depression and dysthymia were strongly associated with any nonheroin opioid use (OR. 5.43; 95% CI, 2.35-12.55 and OR, 7.13; 95% CI, 1.99-25.60, respectively) and with weekly nonheroin opioid use (OR, 8.89; 95% CI, 3.61-21.93 and OR, 11.51; 95% CI, 3.05-42.72, respectively). Among young adults with opioid use, those with heroin use had the highest rates of childhood psychiatric disorders and comorbidities.

CONCLUSIONS AND RELEVANCE

Childhood tobacco use and chronic depression may be associated with impaired reward system functioning, which may increase young adults' vulnerability to opioid-associated euphoria. Preventing and treating early substance use and childhood mental illness may help prevent later opioid use.

First-year college students' weight change is influenced by their randomly assigned roommates' BMI

BACKGROUND

There is ongoing debate about whether friends' greater similarity in Body Mass Index (BMI) than non-friends is due to friend selection, shared environments, or peer influence.

METHODS

First-year college students (n = 104) from a southwestern U.S. university were randomly assigned roommates during the university's housing process, effectively removing friend selection effects. Participant BMI was measured up to four times (T1-T4) across 2015-2016. The influence of roommate baseline BMI (T1) on change in participant BMI over time (T2-T4) was analyzed using a linear mixed effects model adjusted for individual socio-demographics, linear time trends, baseline BMI, and physical clustering of students. A sensitivity analysis examining floormates was also conducted.

RESULTS

Consistent with roommate influence, participants randomized to roommates with a higher BMI gained more weight between times T2 and T4 (β = 0.06; 95% CI = 0.02, 0.10). No shared environment effects (shared campus or floor) were found.

CONCLUSIONS

Randomly assigned roommates influenced each other's weight trajectories. This clarifies that BMI convergence can occur outside of friend selection or shared environments mechanisms.

Beyond Dyads and Triads: A Comparison of Tetrads in Twenty Social Networks

Social psychologists focus on the microlevel features that define interaction, often attending to dyads and triads. We argue that there also is utility in studying how configurations of four actors, or tetrads, pattern our social world. The current project considers the prevalence of directed tetrads across twenty social networks representing five relationship types (friendship, legislative co-sponsorship, Twitter, advice seeking, and email). By comparing these observed networks to randomly generated conditional networks, we identify tetrads that occur more frequently than expected, or network motifs. In all twenty networks, we find evidence for six tetrad motifs that collectively highlight tendencies toward hierarchy, clustering, and bridging in social interaction. Variations across network genres also emerge, suggesting that unique tetrad structural signatures could define different types of interaction.

Interparental Conflict and Delinquency Among Chinese Adolescents: Parental Knowledge as a Mediator and Deviant Peer Affiliation as a Moderator

Interparental conflict has been found to positively affect adolescent delinquency; however, the underlying mechanism that explains this association remains unclear. This study investigated whether parental knowledge mediates the association between interparental conflict and adolescent delinquency, and whether this mediating process is moderated by deviant peer affiliation. To examine this, a total of 3,129 Chinese adolescents (47.27% boys, Mean_age = 14.94 years) completed a survey. Structural equation modeling indicated that the positive association between interparental conflict and adolescent delinquency is mediated by parental knowledge. Moreover, for adolescents with high deviant peer affiliation, interparental conflict was found to positively predict delinquency via parental knowledge; however, this indirect link was non-significant for adolescents with low deviant peer affiliation. These findings highlight the influence of parental knowledge and deviant peer affiliation on the association between interparental conflict and adolescent delinquency. This can provide guidance for the development of effective interventions that address the adverse effects of interparental conflict.

Children's immigrant generational status and delinquency: The mediating effects of friendship networks

A mounting body of empirical studies demonstrates that first-generation immigrant children have a lower level of delinquency and crime but second and third-plus generations report a precipitous increase in these behaviors. Adopting a social network approach, we analyzed the behavioral and structural characteristics of children's friendship networks across the first, second, and third-plus immigrant generations, and investigated the mediating role of these friendship traits in explaining generational disparity. Our results reveal that children's friendship networks differ in structural (e.g., popularity) and behavioral features (e.g., network deviance) across immigrant generations. These friendship features, particularly network peer deviance, the percentage of second-generation friends, and children's popularity mediate the association between immigrant generational status and children's delinquency. Extending previous research, our study highlights the importance of applying the social network approach to understand delinquency disparity across immigrant generations and suggests that the composition of friendship networks play an important role in immigrant children's delinquency involvement.

Social Network Analysis in Child and Adolescent Physical Activity Research: A Systematic Literature Review

BACKGROUND

Regular physical activity (PA) has many benefits for children and adolescents, yet many do not meet PA recommendations. Social context is important for promoting or discouraging PA among children and adolescents. This review aimed to identify social network variables related to PA among children and adolescents.

METHODS

A systematic review of the literature was conducted in September 2018 using PsycINFO, MEDLINE, PubMed, and Web of Science. Included articles needed to (1) be focused on children (aged 5-11 y) or adolescents (aged 12-17 y), (2) include a measure of PA, (3) include a measure of egocentric or sociocentric social connection in which alters were nominated, and (4) perform an analysis between network data and PA.

RESULTS

A search of 11,824 articles was refined to a final sample of 29 articles. Social network themes and concepts such as homophily, centrality, and network composition were related to child and adolescent PA behavior across the literature.

CONCLUSIONS

The impact of an individual's social network is evident on their PA behaviors. More research is needed to examine why these networks form in relation to PA and how interventions can utilize social network analysis to more effectively promote PA, especially in underserved and minority populations.

Peer influence in adolescent drinking behaviour: a protocol for systematic review and meta-analysis of stochastic actor-based modeling studies

INTRODUCTION

Alcohol consumption is a considerable public health problem that is especially harmful to young people. To develop effective prevention programmes targeted at adolescents, it is important to understand the social mechanisms triggering alcohol consumption. Among such mechanisms, peer influence plays an important role. The effects of peer influence are very difficult to evaluate because of the entanglement with social selection, that is, a tendency of people to befriend others with similar behaviour. The recently developed stochastic actor-oriented models (SAOM) approach is designed to disentangle social influence from social selection. The aim of this study is to conduct a systematic review and meta-analysis of studies employing SAOM methodology to evaluate the effects of social influence on adolescent drinking behaviour.

METHODS AND ANALYSIS

In order to analyse the co-evolution of alcohol consumption and adolescent friendship networks, we will collect articles that use SAOM methodology through systematic electronic searches in Web of Science, Scopus, PubMed, The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials), EBSCOhost (MEDLINE, SocINDEX, Academic Source, ERIC), ProQuest (ProQuest Dissertations and Theses Global), PsycINFO (PsycNET), Excerpta Medica database (Embase) and Cumulative Index to Nursing and Allied Health Literature (CINAHL). We will collect the literature from academic journals, dissertations/theses, reports and conference materials. Three reviewers will retrieve and independently assess potentially relevant material in terms of whether they comply with prespecified criteria. Subsequently, we will summarise the results of the studies in a systematic review. If a sufficient number of studies can be found, SAOM quantitative results will be extracted and meta-analysed. The project will go from 1 December 2018 to 1 December 2019.

ETHICS AND DISSEMINATION

Ethical approval will not be required as our work is based on published studies. A list of all the studies included in this work will be available for review. We plan dissemination in a peer-reviewed international scientific journal and through conference presentations. Our review will highlight the peer effect of peers in adolescent drinking behaviour and provide guidance for developing effective prevention and intervention programmes. We expect it to be informative for policy and practice, decision-making as well as for further research in public health and sociology of adolescents.

PROSPERO REGISTRATION NUMBER

CRD42019119836.

Tied Together: Adolescent Friendship Networks, Immigrant Status, and Health Outcomes

This study examines the social integration of adolescent immigrants by directly analyzing the composition of their friendship networks. Using statistical network analysis, I first consider whether adolescents are more likely to befriend peers who share their immigrant generation status in a large, diverse sample of 7th through 12th graders from the National Longitudinal Study of Adolescent to Adult Health (n = 67,586). Next, I test whether having a higher proportion of same-generation friends can protect immigrant youth from experiencing negative health outcomes and adopting risky behaviors. Results indicate that adolescents are more likely to form friendships with peers who share their immigrant generation status and that this tendency is particularly strong for first-generation immigrants. Furthermore, immigrant youth with greater proportions of same-generation friends are less likely to report several negative health behaviors and outcomes. My findings suggest that same-generation friendships can serve as a protective mechanism for immigrant youth, which may help explain the existence of an immigrant health paradox.