Substance Use Disorder in America: Research to Practice, and Back Again

These proceedings summarize the insights shared by nationally renowned panels of experts and overall themes discussed throughout a substance use disorder conference held at the University of Pennsylvania. The conference included experts from academia and public and private sectors, who came together to discuss the gaps in evidence-based substance use policy and practice, with particular emphasis on the opioid epidemic. The day concluded with an interactive session focused on the exchange of ideas and solutions to curb the opioid epidemic. Those ideas are included in these proceeding

Alcohol Perceptions and Behavior in a Residential Peer Social Network

Personalized normative feedback is a recommended component of alcohol interventions targeting college students. However, normative data are commonly collected through campus-based surveys, not through actual participant-referent relationships. In the present investigation, we examined how misperceptions of residence hall peers, both overall using a global question and those designated as important peers using person-specific questions, were related to students’ personal drinking behaviors. Participants were 108 students (88% freshman, 54% White, 51% female) residing in a single campus residence hall. Participants completed an online baseline survey in which they reported their own alcohol use and perceptions of peer alcohol use using both an individual peer network measure and a global peer perception measure of their residential peers. We employed network autocorrelation models, which account for the inherent correlation between observations, to test hypotheses. Overall, participants accurately perceived the drinking of nominated friends but overestimated the drinking of residential peers. Consistent with hypotheses, overestimating nominated friend and global residential peer drinking predicted higher personal drinking, although perception of nominated peers was a stronger predictor. Interaction analyses showed that the relationship between global misperception and participant self-reported drinking was significant for heavy drinkers, but not non-heavy drinkers. The current findings explicate how student perceptions of peer drinking within an established social network influence drinking behaviors, which may be used to enhance the effectiveness of normative feedback interventions

Resistance to Peer influence Moderates the Relationship Between Perceived (But Not Actual) Peer Norms and Binge Drinking in a College Student Social Network

Introduction: Adolescent and young adult binge drinking is strongly associated with perceived social norms and the drinking behavior that occurs within peer networks. The extent to which an individual is influenced by the behavior of others may depend upon that individual’s resistance to peer influence (RPI). Methods: Students in their first semester of college (N = 1323; 54.7% female, 57% White, 15.1% Hispanic) reported on their own binge drinking, and the perceived binge drinking of up to 10 important peers in the first-year class. Using network autocorrelation models, we investigated cross-sectional relationships between participant’s binge drinking frequency and the perceived and actual binge drinking frequency of important peers. We then tested the moderating role of RPI, expecting that greater RPI would weaken the relationship between perceived and actual peer binge drinking on participant binge drinking. Results: Perceived and actual peer binge drinking were statistically significant predictors of participant binge drinking frequency in the past month, after controlling for covariates. RPI significantly moderated the association between perceptions of peer binge drinking and participant’s own binge drinking; this association was weaker among participants with higher RPI compared to those with lower RPI. RPI did not interact with the actual binge drinking behavior of network peers

Enrollment and Assessment of a First-Year College Class Social Network for a Controlled Trial of the Indirect Effect of a Brief Motivational Intervention

Heavy drinking and its consequences among college students represent a serious public health problem, and peer social networks are a robust predictor of drinking-related risk behaviors. In a recent trial, we administered a Brief Motivational Intervention (BMI) to a small number of first-year college students to assess the indirect effects of the intervention on peers not receiving the intervention. Objectives: To present the research design, describe the methods used to successfully enroll a high proportion of a first-year college class network, and document participant characteristics. Methods: Prior to study enrollment, we consulted with a student advisory group and campus stakeholders to aid in the development of study-related procedures. Enrollment and baseline procedures were completed in the first six weeks of the academic semester. Surveys assessed demographics, alcohol use, and social network ties. Individuals were assigned to a BMI or control group according to their dormitory location. Results: The majority of incoming first-year students (1342/1660; 81%) were enrolled (55% female, 52% nonwhite, mean age 18.6 [SD = 0.51]). Differences between the intervention and control group were noted in alcohol use, but were in large part a function of there being more substance-free dormitory floors in the control group. Conclusions: The current study was successful in enrolling a large proportion of a first-year college class and can serve as a template for social network investigations

An Event- and Network-Level Analysis of College Students’ Maximum Drinking Day

Background—Heavy episodic drinking is common among college students and remains a serious public health issue. Previous event-level research among college students has examined behaviors and individual-level characteristics that drive consumption and related consequences but often ignores the social network of people with whom these heavy drinking episodes occur. The main aim of the current study was to investigate the network of social connections between drinkers on their heaviest drinking occasions. Methods—Sociocentric network methods were used to collect information from individuals in the first-year class (N=1342) at one university. Past-month drinkers (N=972) reported on the characteristics of their heaviest drinking occasion in the past month and indicated who else among their network ties was present during this occasion. Results—Average max drinking day indegree, or the total number of times a participant was nominated as being present on another students’ heaviest drinking occasion, was 2.50 (SD = 2.05). Network autocorrelation models indicated that max drinking day indegree (e.g., popularity on heaviest drinking occassions) and peers’ number of drinks on their own maximum drinking occasions were significantly associated with participant maximum number of drinks, after controlling for demographic variables, pregaming, and global network indegree (e.g., popularity in the entire first-year class). Conclusion—Being present at other peers’ heaviest drinking occasions is associated with greater drinking quantities on one’s own heaviest drinking occasion. These findings suggest the potential for interventions that target peer influences within close social networks of drinkers

Do Misperceptions of Peer Drinking Influence Personal Drinking Behavior? Results From a Complete Social Network of First-Year College Students

This study considered the influence of misperceptions of typical versus self-identified important peers\u27 heavy drinking on personal heavy drinking intentions and frequency utilizing data from a complete social network of college students. The study sample included data from 1,313 students (44% male, 57% White, 15% Hispanic/Latinx) collected during the fall and spring semesters of their freshman year. Students provided perceived heavy drinking frequency for a typical student peer and up to 10 identified important peers. Personal past-month heavy drinking frequency was assessed for all participants at both time points. By comparing actual with perceived heavy drinking frequencies, measures of misperceptions of heavy drinking (accurately estimate, overestimate, underestimate) were constructed for both general and important peers. These misperceptions were then used as predictors of concurrent and prospective personal heavy drinking frequency and intentions using network autocorrelation analyses. The majority of students (84.8%) overestimated, 11.3% accurately estimated, and 3.9% underestimated heavy drinking among their general peers, whereas 42.0% accurately estimated, 36.9% overestimated, and 21.1% underestimated important peers\u27 heavy drinking. For both referents, overestimation of peer heavy drinking was associated with more frequent heavy drinking and higher drinking intentions at both time points. Importantly, the effects of underestimating and overestimating close peers\u27 drinking on personal alcohol use were significant after controlling for the influence of misperceptions of general peers\u27 heavy drinking. Close peers are a critical referent group in assessments related to social norms for young adult alcohol use. Implications for prevention and intervention are discussed

A Complex Suite of Forces Drives Gene Traffic from Drosophila X Chromosomes

Theoretical studies predict X chromosomes and autosomes should be under different selection pressures, and there should therefore be differences in sex-specific and sexually antagonistic gene content between the X and the autosomes. Previous analyses have identified an excess of genes duplicated by retrotransposition from the X chromosome in Drosophila melanogaster. A number of hypotheses may explain this pattern, including mutational bias, escape from X-inactivation during spermatogenesis, and the movement of male-favored (sexually antagonistic) genes from a chromosome that is predominantly carried by females. To distinguish among these processes and to examine the generality of these patterns, we identified duplicated genes in nine sequenced Drosophila genomes. We find that, as in D. melanogaster, there is an excess of genes duplicated from the X chromosome across the genus Drosophila. This excess duplication is due almost completely to genes duplicated by retrotransposition, with little to no excess from the X among genes duplicated via DNA intermediates. The only exception to this pattern appears within the burst of duplication that followed the creation of the Drosophila pseudoobscura neo-X chromosome. Additionally, we examined genes relocated among chromosomal arms (i.e., genes duplicated to new locations coupled with the loss of the copy in the ancestral locus) and found an excess of genes relocated off the ancestral X and neo-X chromosomes. Interestingly, many of the same genes were duplicated or relocated from the independently derived neo-X chromosomes of D. pseudoobscura and Drosophila willistoni, suggesting that natural selection favors the traffic of genes from X chromosomes. Overall, we find that the forces driving gene duplication from X chromosomes are dependent on the lineage in question, the molecular mechanism of duplication considered, the preservation of the ancestral copy, and the age of the X chromosome