Michael Pollard

Selection and Influence Mechanisms Associated With Marijuana Initiation and Use in Adolescent Friendship Networks

Friends are thought to influence adolescent drug use. However, few studies have examined the role of drugs in friendship selection, which is necessary to draw sound conclusions about influence. This study applied statistical models for social networks to test the contribution of selection and influence to associations in marijuana use among friends in two large high schools (N = 1,612; M age = 16.4). There was evidence for friend selection based on similar lifetime and current marijuana use at both schools, but friends were found to influence the initiation and frequency of adolescent marijuana use in just one of these schools. There was minimal evidence that peer effects were moderated by personal, school, or family risk factors.

Peer influence and selection effects on adolescent smoking

BACKGROUND Studies showing that adolescents are more likely to smoke if they have friends who smoke typically infer that this is the result of peer influence. However, it may also be due to adolescents choosing friends who have smoking behaviors similar to their own (i.e., selection). One of the most influential studies of influence and selection effects on smoking concluded that these processes contribute about equally to peer group homogeneity in adolescent smoking (Ennett and Bauman, 1994). The goal of this study was to conduct a partial replication of these findings. METHODS Data are from 1223 participants in the National Longitudinal Study of Adolescent Health. Spectral decomposition techniques identified friendship cliques, which were then used as the unit of analysis to examine influence and selection effects over a one-year period. RESULTS Non-smokers were more likely to become smokers if they initially belonged to a smoking (vs. non-smoking) group, and smokers were more likely to become non-smokers if they initially belonged to a non-smoking (vs. smoking) group, indicating an influence effect on both initiation and cessation. Further, group members who changed groups between waves were more likely to select groups with smoking behavior congruent to their own, providing evidence of a selection effect. CONCLUSIONS While our results generally replicate the group analyses reported by Ennett and Bauman (1994), they suggest that peer influence and selection effects on adolescent smoking may be much weaker than assumed based on this earlier research.

Neighborhood characteristics and the initiation of marijuana use and binge drinking

BACKGROUND This study examines whether residential neighborhood characteristics influence the initiation of marijuana use and binge drinking, and if these neighborhood factors heighten or dampen peer influences on substance use. METHODS Predictors of marijuana (N=6516) and binge drinking (N=6630) initiation over a 1-year period were identified using data from the National Longitudinal Study of Adolescent Health. Participants were of ages 12-19 years at baseline. The main predictor variables were neighborhood characteristics, using both objective (proportion of households below the poverty line and female-headed, unemployment rate, residential stability) and subjective (perceived cohesion and safety) measures. Binge drinking was defined as 5 or more drinks in a row. RESULTS Initiation occurred for 12.9% of adolescents in the case of marijuana and 16.4% for binge drinking. Marijuana initiation was more likely among adolescents who lived in neighborhoods with a higher unemployment rate, and binge drinking initiation was more likely among those who perceived greater safety in their neighborhood, after adjusting for other neighborhood characteristics, demographics, friend characteristics, and behavioral and family risk factors. There was no evidence that neighborhood context moderates the associations of peer factors on initiation. CONCLUSIONS Select neighborhood characteristics appear relevant to the initiation of marijuana use and binge drinking, although the mechanisms appear to be distinct for each substance. If these results are found to be robust, future research should aim to better understand how neighborhood context influences the initiation of adolescent substance use in order to inform prevention efforts.

Adolescent romantic relationships and change in smoking status

Although smoking rates have decreased, smoking among adolescents continues to be a problem. Previous research has shown the importance of peer influences on adolescent smoking behavior but has mostly neglected the impact of adolescent romantic relationships. This study examines the influence of romantic relationships with smokers and non-smokers on smoking initiation and cessation over a one-year period using data from the National Longitudinal Study of Adolescent Health (Add Health). For initial non-smokers, we examined whether the total length of time in romantic relationships with smokers and non-smokers at Wave I, as well as amount of exposure to smoking through romantic partners, predicted smoking initiation at Wave II. Among initial regular smokers, we examined whether these same relationship characteristics predicted smoking cessation at Wave II. These analyses were conducted separately for respondents in any type of romantic relationship, as well as just those respondents in close romantic relationships. Results indicated that, for close romantic relationships, cessation was more likely among smokers with more time in relationships with non-smoking partners. Greater exposure to smoking through romantic partners at Wave I significantly decreased the likelihood of cessation among initial smokers and increased the likelihood of initiation among initial non-smokers. For all relationships, greater exposure to smoking through romantic partners at Wave I significantly reduced the likelihood of cessation. These associations held when controlling for best friend smoking, as well as demographic factors and school-level smoking, suggesting that peer-based smoking programs aimed at adolescents should incorporate a focus on romantic relationships.

Longitudinal associations of homophobic name-calling victimization with psychological distress and alcohol use during adolescence

PURPOSE Homophobic victimization, and specifically name-calling, has been associated with greater psychological distress and alcohol use in adolescents. This longitudinal study examines whether sexual orientation moderates these associations and also differentiates between the effects of name-calling from friends and nonfriends. METHODS Results are based on 1,325 students from three Midwestern high schools who completed in-school surveys in 2012 and 2013. Linear regression analysis was used to examine the associations among homophobic name-calling victimization and changes in anxiety symptoms, depressive symptoms, and alcohol use one year later, controlling for other forms of victimization and demographics. RESULTS Homophobic name-calling victimization by friends was not associated with changes in psychological distress or alcohol use among either students who self-identified as heterosexual or those who self-identified as lesbian, gay, or bisexual (LGB). In contrast, homophobic name-calling by nonfriends was associated with increased psychological distress over a one-year period among LGB students and increased drinking among heterosexual students. CONCLUSIONS Homophobic name-calling victimization, specifically from nonfriends, can adversely affect adolescent well-being over time and, thus, is important to address in school-based bullying prevention programs. School staff and parents should be aware that both LGB and heterosexual adolescents are targets of homophobic name-calling but may tend to react to this type of victimization in different ways. Further research is needed to understand the mechanisms through which homophobic victimization increases the risk of psychological distress and alcohol use over time.

A prospective study of marijuana use change and cessation among adolescents

BACKGROUND With marijuana use increasing among American adolescents, better understanding of the factors associated with decreasing use and quitting can help inform cessation efforts. This study evaluates a range of neighborhood, family, peer network, and individual factors as predictors of marijuana use, change, and non-use over one year, and cessation over six years. METHODS Data come from adolescents in Waves I and II of the National Longitudinal Study of Adolescent Health (N=458, one-year sample), or Waves I and III (N=358, six-year sample), and reported using marijuana at least four times in the past month at Wave I. RESULTS Eighteen percent of adolescents stopped using marijuana after six years. Results suggest neighborhood context affects overall use level, whereas neighborhood context and friends were critical to cessation vs. continuation of use. Decrease in use were more likely among adolescents in disadvantaged or less cohesive neighborhoods, or who moved between waves. Non-use after one year was more likely among adolescents who did not move, had fewer marijuana-using friends, and did not exclusively have outside-of-school friends. Cessation at six years was more likely among adolescents in less disadvantaged and more cohesive neighborhoods, and for those with within-school friends. CONCLUSIONS Results highlight the importance of both objective and subjective neighborhood characteristics, as well as peer networks, on adolescent marijuana use. Factors associated with decreases in use appear distinct from those that predict quitting, suggesting that continuation vs. cessation is linked to peers as well as neighborhood context. Relocated and isolated individuals may face challenges with cessation.

Romantic attraction and adolescent smoking trajectories

Research on sexual orientation and substance use has established that lesbian, gay, and bisexual (LGB) individuals are more likely to smoke than heterosexuals. This analysis furthers the examination of smoking behaviors across sexual orientation groups by describing how same- and opposite-sex romantic attraction, and changes in romantic attraction, are associated with distinct six-year developmental trajectories of smoking. The National Longitudinal Study of Adolescent Health dataset is used to test our hypotheses. Multinomial logistic regressions predicting smoking trajectory membership as a function of romantic attraction were separately estimated for men and women. Romantic attraction effects were found only for women. The change from self-reported heterosexual attraction to lesbian or bisexual attraction was more predictive of higher smoking trajectories than was a consistent lesbian or bisexual attraction, with potentially important differences between the smoking patterns of these two groups.

Nonmarital Cohabitation, Marriage, and Health Among Adolescents and Young Adults

A considerable amount of research has established that the married live longer, healthier lives than the previously- and never-married. Similar research on the health benefits of cohabitation is sparse, and virtually nonexistent from adolescence into young adulthood despite substantial levels of cohabitation at these ages. Using longitudinal data from Add Health (1995-2001/2002) and generalized linear model techniques the authors investigate the impact of nonmarital cohabitation and marriage on a range of physical and mental health indicators and health behaviors. They also consider the mechanisms through which cohabitation affects health (i.e., selection and protection) and contrast the health effects of cohabitation with those reported for marriage at these relatively early ages. Results indicate that the health benefits of marriage among this sample are weaker than expected based on previous studies of marriage and health, but broader than those for cohabitation. This is not unexpected given the relatively young ages of marriage in Add Health compared to other datasets containing respondents at older ages, which comprise much of the previous marriage and health literature. Cohabitors report lower physical health than married or single individuals, but that cohabiting males receive some mental health benefits relative to singles. Cohabiting men and women also engage in some better health behaviors than singles. There also appears to be some selection into cohabitation and marriage by individuals with relatively poor mental health and health behaviors that may contribute to the observed health differentials.

Methodology of the 2016 RAND Presidential Election Panel Survey (PEPS)

The 2016 RAND Presidential Election Panel Survey uses the American Life Panel (ALP) to study voting intentions, public opinion, and voter behavior. This document provides a detailed description of our methodology.