1. Dick DM, Nasim A, Edwards AC, Salvatore J, Cho SB, Adkins A, Meyers J, Yan J, Cooke M, Clifford J, Goyal N, Halberstadt L, Ailstock K, Neale Z, Oplaesky J, Hancock L, Donovan KK, Sun C, Riley B, Kendler KS. Spit for Science: Launching a longitudinal study of genetic and environmental influences on substance use and emotional health at a large US university. Frontiers in Genetics (Behavioral and Psychiatric), 2014 Mar 6;5:47. doi: 10.3389/fgene.2014.00047. PMID: 24639683. PMCID: PMC3944794
Abstract: Finding genes involved in complex behavioral outcomes, and understanding the pathways by which they confer risk, is a challenging task, necessitating large samples that are phenotypically well characterized across time. We describe an effort to create a university-wide research project aimed at understanding how genes and environments impact alcohol use and related substance use and mental health outcomes across time in college students. Nearly 70% of the incoming freshman class (N = 2715) completed on-line surveys, with 80% of the students from the fall completing spring follow-ups. 98% of eligible participants also gave DNA. The participants closely approximated the university population in terms of gender and racial/ethnic composition. Here we provide initial results on alcohol use outcomes from the first wave of the sample, as well as associated predictor variables. We discuss the potential for this kind of research to advance our understanding of genetic and environment influences on substance use and mental health outcomes.
2. Salvatore JE, Kendler KS, Dick DM. Romantic relationship status and alcohol use and problems across the first year of college. Journal of Studies on Alcohol and Drugs. 2014 Jul;75(4)580-9. PMID: 24988257. PMCID: PMC4108599
Abstract: Objective: We examined the associations between romantic relationship status and alcohol use and problems in a large sample of first-year college students. Method: Participants (n = 2,056) came from a longitudinal study of college students who answered questions about relationship status (single, in an exclusive relationship, or dating several people), alcohol use, and alcohol problems at two time points across their first year. Results: After we controlled for a number of covariates (parental alcohol problems, high school conduct problems, peer deviance, and extraversion), we found that dating several people was associated with higher alcohol use and problems, compared with being single or being in an exclusive relationship, at the follow-up assessment only, with modest effect sizes. Being in an exclusive relationship was not associated with lower alcohol use or problems compared with being single. Relationship dissolution was associated with a modest longitudinal increase in alcohol problems. Conclusions: It is important to consider alternative relationship statuses (e.g., dating several people) for understanding the association of romantic status with alcohol use and problems in college-aged samples. Involvement in an exclusive romantic relationship (vs. being single) in this age group is not associated with the behavioral health benefits documented in older-adult samples. College students dating several people may be at risk for high levels of alcohol use or problems and may benefit from targeted interventions. Those who have recently experienced a breakup also may be at risk for increases in alcohol problems, although the clinical relevance of this finding should be tempered by the small observed effect size.
3. Kendler KS, Myers J, Dick DM. The stability and predictors of peer group deviance in university students. Social Psychiatry and Psychiatric Epidemiology. 2015 Sep;50(9):1463-70. doi: 10.1007/s00127-015-1031-4. Epub 2015 Feb 22. PMID: 25702166. PMCID: PMC454657
Abstract: Peer group deviance (PGD) is strongly associated with current and future externalizing behaviors. Debate remains about the degree to which this association arises from social selection. The first year of university constitutes a social experiment in which most individuals leave their home environment and recreate for themselves a new peer group. Methods: PGD was measured in newly arrived university students and then 6 and 18 months later. Other personality and family traits were also assessed Results: PGD reported for high school friends at the start of university and university friends 6 months later were substantially correlated (+0.60). This correlation was only slightly diminished if restricted to students whose home was greater than 50 miles from the university. PGD was strongly predicted across three cohorts by male sex (+), extraversion (+), conscientiousness (-), a family history of alcohol use disorders (+) and depression (+), and religiosity (-).These predictors of PGD had a relatively stable impact over 18 months and, aside from sex, differed only modestly in males and females. Conclusions: As individuals change social groups from high school to university, the level of PGD remains relatively stable, suggesting that individuals play a strong role in selecting peer groups with consistent characteristics. PGD is also predicted cross-sectionally and longitudinally by personality, family background and religiosity. Our results suggest that the association between personal and peer deviance is due at least in part to the effects of social selection.
4. Dick DM, Hancock LC. Integrating basic research with prevention/intervention to reduce risky substance use among college students. Frontiers in Psychology. 2015 May 7;6544. doi: 10.3389fpsyg.2015.00544. eCollection 2015. PMID: 25999878. PMCID: PMC4423347
Abstract: Too often basic research on etiological processes that contribute to substance use outcomes is disconnected from efforts to develop prevention and intervention programming. Substance use on college campuses is an area of concern where translational efforts that bring together basic scientists and prevention/intervention practitioners have potential for high impact. We describe an effort at a large, public, urban university in the United States to bring together researchers across the campus with expertise in college behavioral health with university administration and health/wellness practitioners to address college student substance use and mental health. The project “Spit for Science” examines how genetic and environmental influences contribute to behavioral health outcomes across the college years. We argue that findings coming out of basic research can be used to develop more tailored prevention and intervention programming that incorporates both biologically and psychosocially influenced risk factors. Examples of personalized programming suggest this may be a fruitful way to advance the field and reduce risky substance use.
5. Kendler KS, Edwards A, Myers J, Cho SB, Adkins A, Dick D. The predictive power of family history measures of alcohol and drug problems and internalizing disorders in a college population. American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics. 2015 July;168(5):337-46. doi: 10.1002/ajmg.b.32320. Epub 2015 May 6. PMID: 25946510. PMCID: PMC4466079 [Available on 2016-7-1]
Abstract: A family history (FH) of psychiatric and substance use problems is a potent risk factor for common internalizing and externalizing disorders. In a large web-based assessment of mental health in college students, we developed a brief set of screening questions for a FH of alcohol problems (AP), drug problems (DP) and depression-anxiety in four classes of relatives (father, mother, aunts/uncles/grandparents, and siblings) as reported by the student. Positive reports of a history of AP, DP, and depression-anxiety were substantially correlated within relatives. These FH measures predicted in the student, in an expected pattern, dimensions of personality and impulsivity, alcohol consumption and problems, smoking and nicotine dependence, use of illicit drugs, and symptoms of depression and anxiety. Using the mean score from the four classes of relatives was more predictive than using a familial/sporadic dichotomy. Interactions were seen between the FH of AP, DP, and depression-anxiety and peer deviance in predicting symptoms of alcohol and tobacco dependence. As the students aged, the FH of AP became a stronger predictor of alcohol problems. While we cannot directly assess the validity of these FH reports, the pattern of findings suggest that our brief screening items were able to assess, with some accuracy, the FH of substance misuse and internalizing psychiatric disorders in relatives. If correct, these measures can play an important role in the creation of developmental etiologic models for substance and internalizing psychiatric disorders which constitute one of the central goals of the overall project.
6. Conley A, Overstreet CM, Hawn SE, Kendler KS, Dick DM, Amstadter AB. Prevalence and predictors of sexual assault among a college sample. American Journal of Public Health. 2016 Sep 14:1-9. [Epub ahead of print]. doi: 10.1080/07448481.2016.1235578 PMID: 27628533
Abstract: This study examined the prevalence and correlates of precollege, college-onset, and repeat sexual assault (SA) within a representative student sample. PARTICIPANTS: A representative sample of 7,603 students. METHODS: Incoming first-year students completed a survey about their exposure to broad SA prior to college, prior trauma, personality, relationships, and mental health. Broad SA was then reassessed each spring semester while enrolled. RESULTS: Nearly 20% of the sample reported experiencing broad SA, with women endorsing significantly higher rates compared with males. Prior victimization before coming to college was related to a greater risk of victimization in college, and there was no statistically significant difference between males and females who reported revictimization. Correlates of college-onset broad SA were found and are discussed. CONCLUSIONS: Given the need for SA intervention and prevention on college campuses, identification of factors potentially contributing to exposure within this population is essential.
7. Savage JE, Neale Z, Cho SB, Hancock L, Kalmijn JA, Smith TL, Schuckit MA, Kidd Donovan K, Dick DM. Level of response to alcohol as a factor for targeted prevention in college students. Alcoholism: Clinical and Experimental Research. 2015
Abstract: Heavy alcohol consumption and alcohol problems among college students are widespread and associated with negative outcomes for individuals and communities. Although current methods for prevention and intervention programming have some demonstrated efficacy, heavy drinking remains a problem. A previous pilot study and a recent large-scale evaluation (Schuckit et al., , ) found that a tailored prevention program based on a risk factor for heavy drinking, low level of response (low LR) to alcohol, was more effective at reducing heavy drinking than a state-of-the-art (SOTA) standard prevention program for individuals with the low LR risk factor. Methods: This study enrolled 231 first-semester college freshmen with either high or low LR into the same level of response-based (LRB) or SOTA online prevention programs as in the previous reports (consisting of 4 weeks of video modules), as well as a group of matched controls not receiving alcohol prevention, and compared changes in alcohol use between these groups across a 6-month period. Results: Individuals in alcohol prevention programs had a greater reduction in maximum drinks per occasion and alcohol use disorder symptoms than controls. There was limited evidence for interactions between LR and prevention group in predicting change in alcohol use behaviors; only among participants with strict adherence to the program was there an interaction between LR and program in predicting maximum drinks per occasion. However, overall, low LR individuals showed greater decreases in drinking behaviors, especially risky behaviors (e.g., maximum drinks, frequency of heavy drinking) than high LR individuals. Conclusions: These results indicate that prevention programs, including brief and relatively inexpensive web-based programs, may be effective for persons at highest risk for heavier drinking, such as those with a low LR. Tailored programs may provide incremental benefits under some conditions. Long-term follow-ups and further investigations of tailored prevention programs based on other risk factors are needed.
8. Berenz EC, Cho SB, Overstreet C, Kendler K, Amstadter AB, Dick DM. Longitudinal investigation of interpersonal trauma exposure and alcohol use trajectories. Addictive Behaviors. 2016 Feb;53:67-73. doi: 10.1016/j.addbeh.2015.09.014. Epub 2015 Sep 25. PMID: 26454552. PMCID: PMC4699169. [Available on 2017-02-01]
Abstract: The current longitudinal study examined associations between interpersonal potentially traumatic events (PTEs; i.e., sexual or physical assault) and changes in alcohol consumption among incoming college students. Methods: 1197 students (68% female) participating in a university-wide research study were included in analyses. Assessments were administered at three time-points and included measures of alcohol use, PTEs (Life Events Checklist), and a screener for possible PTSD symptoms (abbreviated Primary Care PTSD Screen). Linear growth curve models were fit to the three repeated measures of alcohol quantity and frequency to determine the role of pre-college and college-onset interpersonal PTEs and possible PTSD symptoms on patterns of alcohol use. Results: Pre-college interpersonal PTE was associated with greater baseline alcohol use for female but not male students. College-onset interpersonal PTE predicted greater alcohol use at concurrent and future assessments for women but not men, beyond the effects of pre-college PTE. Pre-college possible PTSD symptoms did not predict baseline or change in alcohol use. Conclusions: There may be a stronger and longer-lasting impact of interpersonal PTE for college women compared to men on alcohol phenotypes, although replication in studies oversampling men endorsing interpersonal PTE is needed.
9. Cho SB, Llaneza DC, Adkins AE, Cooke M, Kendler KS, Clark SL, Dick DM. Patterns of Substance Use Across the First Year of College and Associated Risk Factors. Frontiers in Psychiatry. 2015 Oct 27;6:152. doi: 10.3389/fpsyt.2015.00152. PMID: 26578984. PMCID: PMC4621385
Abstract: Starting college is a major life transition. This study aims to characterize patterns of substance use across a variety of substances across the first year of college and identify associated factors. We used data from the first cohort (N = 2056, 1240 females) of the “Spit for Science” sample, a study of incoming freshmen at a large urban university. Latent transition analysis was applied to alcohol, tobacco, cannabis, and other illicit drug uses measured at the beginning of the fall semester and midway through the spring semester. Covariates across multiple domains – including personality, drinking motivations and expectancy, high school delinquency, peer deviance, stressful events, and symptoms of depression and anxiety – were included to predict the patterns of substance use and transitions between patterns across the first year. At both the fall and spring semesters, we identified three subgroups of participants with patterns of substance use characterized as: (1) use of all four substances; (2) alcohol, tobacco, and cannabis use; and (3) overall low substance use. Patterns of substance use were highly stable across the first year of college: most students maintained their class membership from fall to spring, with just 7% of participants in the initial low substance users transitioning to spring alcohol, tobacco, and cannabis users. Most of the included covariates were predictive of the initial pattern of use, but covariates related to experiences across the first year of college were more predictive of the transition from the low to alcohol, tobacco, and cannabis user groups. Our results suggest that while there is an overall increase in alcohol use across all students, college students largely maintain their patterns of substance use across the first year. Risk factors experienced during the first year may be effective targets for preventing increases in substance use.
10. Salvatore JE, Thomas NS, Cho SB, Adkins A, Kendler KS, Dick DM. The role of romantic relationship status in pathways of risk for emerging adult alcohol use. Psychology of Addictive Behaviors. 2016 May;30(3):335-44. doi: 10.1037/adb0000145. PMID: 27214170. PMCID: PMC4880412 [Available on 2017-05-01]
Abstract: Dating several people in emerging adulthood has been associated with higher alcohol use compared with being single or being in an exclusive relationship. As a follow-up to that report, we examined whether romantic relationship status is part of a pathway of risk between antecedent alcohol use risk factors and subsequent alcohol outcomes. Participants were 4,410 emerging adults assessed at 2 time-points during their first year of college. We found that a parental history of alcohol problems was indirectly related to dating several people via 2 modestly correlated pathways. The first pathway was through conduct problems. The second pathway was through positive urgency (i.e., a positive emotion-based predisposition to rash action). In turn, dating several people was associated with higher alcohol use. Our results suggest that these familial and individual-level alcohol risk factors are related to emerging adults' selection into subsequent romantic relationship experiences that are associated with higher alcohol use. These findings have implications for how romantic relationship experiences may fit into developmental models of the etiology of alcohol use.
11. Berenz EC, Kevorkian S, Chowdhury N, Dick DM, Kendler KS, & Amstadter AB (2016). Posttraumatic stress disorder symptoms, anxiety sensitivity, and alcohol use motives in college students with a history of interpersonal trauma. Psychology of Addictive Behaviors, 30, 755-763.
Abstract: Posttraumatic stress disorder (PTSD) symptoms are associated with coping-motivated alcohol use in trauma-exposed samples. However, it is unclear which individuals experiencing PTSD symptoms are at greatest risk for alcohol-use problems following trauma exposure. Individuals endorsing high anxiety sensitivity, which is the fear of anxiety and related sensations, may be particularly motivated to use alcohol to cope with PTSD symptoms. In the current study, we examined the moderating role of anxiety sensitivity in the association between PTSD symptoms and coping motives in a sample of 295 young adults with a history of interpersonal trauma and current alcohol use. Participants completed measures of past 30-day alcohol consumption, trauma history, current PTSD symptoms, anxiety sensitivity, and alcohol-use motives. Results of hierarchical multiple regression analyses indicated that greater anxiety sensitivity was significantly associated with greater coping (β = .219) and conformity (β = .156) alcohol-use motives, and greater PTSD symptoms were associated with greater coping motives (β = .247), above and beyond the covariates of sex, alcohol consumption, trauma load, and noncriterion alcohol-use motives. The interaction of anxiety sensitivity and PTSD symptoms accounted for additional variance in coping motives above and beyond the main effects (β = .117), with greater PTSD symptoms being associated with greater coping motives among those high but not low in anxiety sensitivity. Assessment and treatment of PTSD symptoms and anxiety sensitivity in young adults with interpersonal trauma may be warranted as a means of decreasing alcohol-related risk in trauma-exposed young adults.
12. Moore AA, Overstreet C, Kendler KS, Dick D, Adkins A, Amstadter AB. Potentially traumatic events, personality and risky sexual behavior in undergraduate college students. Psychological Trauma: Theory, Research, Practice, and Policy. 2016 Jun 27. doi: 10.1037/tra0000168. PMID: 27348066. [Epub ahead of print].
Abstract: Impulsivity and extraversion have demonstrated associations with risky sexual behavior (RSB) and potentially traumatic events (PTEs). In addition, interpersonal trauma appears to be associated with RSB, but research on the relationship between RSB and noninterpersonal PTEs (e.g., accidental) is lacking. The current study aims to investigate the relationships between personality (i.e., impulsivity, extraversion), RSB and multiple types of PTEs (i.e., accidental, physical, or sexual). Method: Personality and demographic characteristics were assessed during participants' (N = 970) first semester of college, past-12 month PTEs and RSB were assessed during the second semester of participants' junior year. Multiple linear regression was used to examine the relationship between PTEs, personality factors, and RSB. Analyses were also conducted to examine the potential mediating effect of interpersonal PTEs on the relationship between personality and RSB. Results: Impulsivity and extraversion were significantly positively associated with RSB. Both physical and sexual PTEs, but not accidental PTEs, were also significantly positively associated with RSB. Sexual PTEs significantly mediated the relationship between impulsivity and RSB. Conclusions: This is the first study to date to simultaneously examine the relationship between personality, RSB, and types of PTEs in a large sample of young adults. Exposure to interpersonal trauma appears to be a salient factor in the relationship between personality, specifically impulsivity, and RSB. These results indicate that college students may benefit from education regarding the potential negative outcomes of RSB, and that individuals with a history of interpersonal PTEs may be at increased risk for sexual risk taking.
13. Cooke ME, Nasim A, Cho SB, Kendler KS, Clark SL, Dick DM. Predicting tobacco use across the first year of college. American Journal of Health Behaviors. 2016 Jul 40(4): 484-95. DOI:10.5993/AJHB.40.4.10
Abstract: The purpose of this study was to assess patterns of tobacco use across the first year of college, transitions in use, and associated predictors. Methods: The frequency of tobacco use (cigarettes, cigars, smokeless tobacco, and hookah) during the fall and spring of 4073 college students' first year at college were used as indicators in latent class (LCA) and latent transition analyses (LTA). Results: The LCA yielded 3 classes that represent levels of use frequency and not specific tobacco product classes: non-using, experimenting, and frequent using. The LTA results demonstrate stability in class membership from fall to spring. The most common transition was for the fall experimenters to transition out of experimentation. A series of demographic, environmental, and intrapersonal predictors were found to influence both fall class membership, and transitions from fall to spring. Conclusions: Students are likely to use multiple alternative tobacco products along with cigarettes. Their frequency of use of these products is fairly stable across the first year of college. Predictors reflecting experiences during the first year of college had the greatest impact on college tobacco use, demonstrating the importance of the college experience on young adult tobacco use.
14. Bono R, Barnes A, Dick DM, Kendler KS. Drinking, Cigarette Smoking, and Employment among American College Freshmen at a Four-Year University. Substance Use and Misuse. 2016 Oct 18:1-12. [Epub ahead of print] doi: 10.1080/10826084.2016.1223136. PubMed PMID: 27754728
Abstract: For American college students, alcohol and cigarette use are important health concerns, and employment concurrent with school attendance is on the rise. Given the lifelong importance of employment and substance use trajectories begun in college, parsing out the relationship between the two is meaningful. Objective: This study's purpose is to determine whether employment during college is associated with substance use. Methods: Cross-sectional associations between employment (work hours, earnings) and substance use (drinking frequency, drinking quantity, smoking frequency) were estimated using partial proportional odds models in a sample of N = 1457 freshmen attending a large, public 4-year university in 2011, after accounting for demographics, personality, social environment, and parental influences. Results: Working 10 more hours and earning $50 more per week as a freshman had modest positive associations with higher smoking frequency and with moderate drinking frequency and quantity prior to adjustment. After adjustment, work hours remained modestly associated with moderate drinking frequency and quantity. No adjusted associations were found among employment measures and smoking or between weekly earnings and drinking frequency. Different relationships emerged for moderate versus heavy alcohol use frequency and quantity. Conclusions: Both employment and substance use are commonplace among college freshmen. After extensive controls for potential confounders, the relationship between the two appears modest. Employment may yet play a role in college student substance use, but work hours and earnings are likely only small parts of a larger web of influences on drinking and smoking.
15. Homman LE, Edwards AC, Cho SB, Dick DM, Kendler KS. Gender and direction of effect of alcohol problems and internalising symptoms in a longitudinal sample of college students. Substance Use and Misuse. Epub 2016 Nov 16. doi: 10.1080/10826084.2016.1233983
Abstract: Alcohol problems and internalizing symptoms are consistently found to be associated but how they relate to each other is unclear. Objective: The present study aimed to address limitations in the literature of comorbidity of alcohol problems and internalizing symptoms by investigating the direction of effect between the phenotypes and possible gender differences in college students. Method: We utilized data from a large longitudinal study of college students from the United States (N = 2607). Three waves of questionnaire-based data were collected over the first two years of college (in 2011–2013). Cross-lagged models were applied to examine the possible direction of effect of internalizing symptoms and alcohol problems. Possible effects of gender were investigated using multigroup modeling. Results:There were significant correlations between alcohol problems and internalizing symptoms. A direction of effect was found between alcohol problems and internalizing symptoms but differed between genders. A unidirectional relationship varying with age was identified for males where alcohol problems initially predicted internalizing symptoms followed by internalizing symptoms predicting alcohol problems. For females, a unidirectional relationship existed wherein alcohol problems predicted internalizing symptoms. Conclusions/Importance: We conclude that the relationship between alcohol problems and internalizing symptoms is complex and differ between genders. In males, both phenotypes are predictive of each other, while in females the relationship is driven by alcohol problems. Importantly, our study examines a population-based sample, revealing that the observed relationships between alcohol problems and internalizing symptoms are not limited to individuals with clinically diagnosed mental health or substance use problems.
16. Bryant N, Arendt J, Kendler KS, Dick DM, Adkins A. From saliva samples to the classroom and beyond: What college students are telling us about genetic and environmental influences on substance use and emotional health. Substance Abuse Library and Information Studies (2016) Volume III, Issue I. Pg. 4-10
Abstract: In 2011, researchers at Virginia Commonwealth University launched “Spit for Science,” a large-scale longitudinal study in which nearly 9,900 undergraduate students are currently enrolled. Students will be followed across their college years and beyond to understand how genetic and environmental factors influence substance use and emotional health over time. This presentation highlights several facets of the project. A collaboration between a researcher and an interdisciplinary team of librarians demonstrates how the data are being integrated into the classroom to enhance undergraduate students’ understanding of the research process. We also discuss multidisciplinary collaborations that have evolved from the project as well as the DNA component, including work in progress and work that remains. If replicated at other universities, this model holds promise for better understanding the associations between genes and substance use and mental health disorders.
17. Overstreet CM, Berenz EC, Kendler KS, Dick DM, Amstadter AB. Predictors and mental health outcomes of potentially traumatic event exposure. Psychiatry Research (2017) Volume 247, Pages 296-304 doi: 10.1016/j.psychres.2016.10.047
Abstract: The aims were two-fold: to examine prevalence and correlates of lifetime potentially traumatic event (PTE) exposure and to explore the relationships between PTE exposure and mental health outcomes (i.e., trauma related distress, alcohol use quantity and frequency, depression symptoms, and anxiety symptoms) within a large sample of college freshmen. 6120 participants, consisting of three cohorts of incoming freshman at a large southeastern university, completed an online assessment battery measuring a multitude of factors including PTEs, personality, relationships (i.e., parental and peer), and mental health. The majority (81.8%) of participants endorsed experiencing at least one PTE within their lifetime and 39.0% reported at least one interpersonal trauma (i.e., physical assault, sexual assault, other unwanted or uncomfortable sexual situation). The average number of PTE categories endorsed was 1.71 (SD=1.30), and 8.7% of participants reported experiencing four or more separate PTE categories pre-college entry. Female gender and peer deviance were consistently associated with PTE exposure and symptoms of psychopathology. Furthermore, a history of interpersonal PTE exposure was associated with increased alcohol use (i.e., frequency and quantity), trauma related distress, depressive symptoms, and anxiety symptoms. The data demonstrate high prevalence PTE exposure among young adults and the clinical significance of a PTE history.
18. Spindle T, HIler M, Cooke M, Eissenberg T, Kendler KS, Dick DM. Electronic cigarette use and uptake of cigarette smoking: A longitudinal examination of US college students. Addictive Behaviors, in press.
Abstract: Introduction: Electronic cigarette (e-cigarette) use prevalence is increasing among U.S. adolescents and adults but recent longitudinal data for college/university students are scarce. Furthermore, the extent that e-cigarette use is associated with the onset of cigarette smoking and the factors that lead to the uptake of e-cigarettes in college students has not been explored. Methods: 3757 participants from a Mid-Atlantic university (women: 66%; White: 45%; Black: 21%; Asian: 19%; Hispanic/Latino: 6%) were surveyed in 2014 and again in 2015. Results: Among participants reporting never smoking at time 1, those who had ever tried e-cigarettes or were currently using e-cigarettes (at least one use in past 30days) were more likely to have ever tried cigarettes by time 2 relative to individuals who had not used e-cigarettes. Ever use of e-cigarettes (but not current use) also increased participants' likelihood of being current cigarette smokers at time 2. Among initial never users of e-cigarettes or cigarettes, males and ever marijuana users had an increased probability of trying e-cigarettes by time 2. Furthermore, less perseverance (an index of impulsivity) and ever use of other tobacco products increased initial never users' chances of trying both cigarettes and e-cigarettes by time 2. Conclusions: Given that never-smoking participants who had tried e-cigarettes were more likely to initiate cigarette use later, limiting young adults' access to these products may be beneficial. As the long-term health implications of e-cigarette use become clearer, predictors of e-cigarette use could help identify future populations likely to use and abuse these products.
19. Lind MJ, Baylor A, Overstreet CM, Hawn SE, Rybarczyk BD, Kendler KS, Dick DM, Amstadter AB. Relationships between potentially traumatic events, sleep disturbance, and symptoms of PTSD and alcohol use disorder in a young adult sample. Sleep Medicine(2017) Volume 34, Pages 141-147 doi: 10.1016/j.sleep.2017.02.024.
Abstract: Traumatic events, particularly those that are interpersonal in nature, are associated with increased risk for co-occurring sequelae, including sleep disturbances, posttraumatic stress disorder (PTSD), and alcohol use disorder (AUD). However, the associations between these phenotypes have not been explored among college students. Methods: We examined relationships between type of potentially traumatic event (PTE) exposure (pre-college) and sleep disturbances, as well as mediating effects of lifetime PTSD and AUD symptoms on these relationships, in a large undergraduate sample (N = 1599, 64.7% female). Hierarchical linear regressions were conducted, beginning with demographics and then adding interpersonal and accidental PTEs in a stepwise regression; mediation analyses were run. Results: Within the sample, 33.7% endorsed at least one interpersonal PTE, while 64.4% endorsed at least one accidental PTE. Hierarchical regressions demonstrated that interpersonal (β = 0.202, p = 0.000), but not accidental PTE exposure significantly predicted disturbed sleep. Both PTSD and AUD symptoms significantly mediated (p values < 0.001) the relationship between interpersonal PTE exposure and sleep, with indirect effects accounting for 61% and 17% of total effects, respectively. In the correlated mediation model, both disorders remained significant mediators (p < 0.001), with indirect effects accounting for 56% (PTSD symptoms) and 14% (AUD symptoms) of total effects on sleep. Conclusions: Results suggest that interpersonal PTEs are more potent predictors of sleep problems than accidental PTEs. Further, trauma exposure psychiatric symptom sequelae (PTSD, AUD) account for part of the relationship between interpersonal PTE exposure and disturbed sleep, which both independently and jointly suggests that treating PTSD and AUD symptoms in college students may also improve sleep.
20. O’Shea T, Thomas NS, Webb BT, Dick DM, Kendler KS, & Chartier, KG. ALDH2 rs671 and peer drinking in East Asian college students. The American Journal of Drug and Alcohol Abuse, (2017) Epub ahead of print
Abstract: The ALDH2*2 allele (A-allele) at rs671 is more commonly carried by Asians and is associated with alcohol-related flushing, a strong adverse reaction to alcohol that is protective against drinking. Social factors, such as having friends who binge drink, also contribute to drinking in Asian youth. Objective: This study examined the interplay between ALDH2*2, peer drinking, and alcohol consumption in college students. We hypothesized that the relationship between ALDH2*2 and standard grams of ethanol per month would vary based on the level of peer drinking. Methods: Subjects (N = 318, 63.25% female) were East Asian college students in the United States who reported drinking alcohol. Data were from the freshman year of a university survey that included a saliva DNA sample. ALDH2*2 status was coded ALDH2*2(+) (A/G and A/A genotypes) and ALDH2*2(-) (G/G genotype). Peer drinking was students' perception of how many of their friends "got drunk". Results: Main effects of ALDH2*2(-) and having more friends who got drunk were associated with greater alcohol consumption. The ALDH2*2 × peer drunkenness interaction showed a stronger positive association with alcohol consumption for ALDH2*2(-) versus ALDH2*2(+) at increasing levels of peer drunkenness. Follow-up comparisons within each peer drunkenness level identified significantly higher alcohol consumption for ALDH2*2(-) compared to ALDH2*2(+) at the all friends got drunk level. Conclusion: There was evidence of a stronger effect for ALDH2*2(-) compared to ALDH2*2(+) with greater alcohol use when students were more exposed to peer drinking. Findings contribute to a growing literature on the interrelationships between genetic influences and more permissive environments for alcohol consumption.
21. Peterson RE, Edwards AC, Bacanu SA, Dick DM, Kendler KS, Webb BT. The Utility of empirically assigning ancestry groups in cross-population genetic studies of addiction. Am J Addict (2017) 26(5) 494-501 doi: 10.1111/ajad.12586.
Abstract: Given moderate heritability and significant heterogeneity among addiction phenotypes, successful genome-wide association studies (GWAS) are expected to need very large samples. As sample sizes grow, so can genetic diversity leading to challenges in analyzing these data. Methods for empirically assigning individuals to genetically informed ancestry groups are needed. Methods: We describe a strategy for empirically assigning ancestry groups in ethnically diverse GWAS data including extensions of principal component analysis (PCA) and population matching through minimum Mahalanobis distance. We apply these methods to data from Spit for Science (S4S): the University Student Survey, a study following college students longitudinally that includes genetic and environmental data on substance use and mental health (n = 7,603).
22. Bares, C.B., Dick, D., Kendler, K.S. (in-press). Nicotine dependence, internalizing symptoms, mood variability and daily tobacco use among young adult smokers. Addictive Behaviors: Special Issue on Ambulatory Assessment.
Abstract: Introduction: Tobacco use among college aged young adults continues to rise. Previous studies have suggested a bidirectional relationship between internalizing symptoms, mood variability and tobacco use. Examining the association of within-individual differences in negative mood and cigarette use, while controlling for the influence of internalizing symptoms, could provide a test regarding the direction of causation between internalizing symptoms and cigarette use. Methods: Data for this study came from a sample of college students (n=39, 59% female, mean age 20.4 years) who reported regular tobacco cigarette use and participated in a 21-day ecological momentary assessment (EMA) study assessing cigarette use and mood. Results: A three-level hierarchical linear model accounting for the structure of 1,896 occasions of cigarette use nested within days and individuals indicated that within-individual variability in negative mood was associated with smoking more cigarettes at each occasion, after taking into account the influence of internalizing symptoms and nicotine dependence. Conclusions: Negative mood variability might be indexing an occasion-level measure of internalizing symptoms that varies within individuals and leads to consuming more cigarettes.
23. Chowdhury, N., Kevorkian, S., Hawn, S.E., Amstadter, A.B., Dick, D., Kendler, K.S., Berenz, E.C. (2018). Associations between personality and distress tolerance among trauma-exposed young adults. Personality and Individual Differences, 120, 166-170.
Abstract: Low distress tolerance (DT) is related to negative mental health outcomes, particularly among trauma-exposed populations, who are at greater risk for mental health problems. However, little is known about potential etiological factors underlying the development of perceived (i.e., self-report) or behaviorally assessed DT. The present study examined associations between Big Five personality factors (i.e., openness, conscientiousness, extraversion, agreeableness, & neuroticism) and multiple measures of DT. Participants were 440 college students (71.4% women) endorsing a history of one or more potentially traumatic events. Participants completed the abbreviated Big Five Inventory (BFI), Distress Tolerance Scale (DTS), Discomfort Intolerance Scale (DIS), breath-holding task, and Paced Auditory Serial Addition Test (PASAT). Results of a series of hierarchical linear regressions indicated that higher levels of neuroticism and lower levels of conscientiousness were significantly associated with lower DTS scores, but no other DT measures. Greater extraversion was significantly associated with greater DT on the DIS and was nominally associated with greater DT on the PASAT. Lower levels of openness were associated with lower DT on the breath-holding task. Individual differences in normal personality traits account for significant variation in multiple measures of DT and may provide insight into the etiology of various forms of DT.
Berenz EC, Vukanovic A, Kevorkain S, Gonzales RE, Chowdhurry N, Dutcher CD, Dick DM, Kendler KS, Amstadter AB. Childhood trauma and distress tolerance: A multi-modal study in independent samples. Under review.
Bourdon J, Moore AA, Do EK, Kendler KS, Dick DM. The relationship between on-campus service utilization and common mental health symptoms in undergraduate college students. Under review
Cho SB, Aliev F, Kendler KS, Davies AG, Dick DM, Bettinger JC. The association of C-terminal-binding protein CTBP1 and CTBP2 genes with alcohol problems and externalizing behavior. Under review
Cooke M, Neale ZE, Barr PB, Myers J, Dick DM, Kendler KS, Edwards AC. The role of social, familial, and individual-level factors on multiple alcohol use outcomes during the first year of university. Under review
Do EK, Cooke M, Dick DM, Kendler KS, Maes H. Prevalence and correlates of tobacco use in Spit for Science. Under review
Docherty AR, Moscati A, Dick DM, Savage JE, Salvatore JE, Cooke M, Aliev F, Moore AA, Peterson RE, Edwards AC, Riley BP, Adkins DE, Webb BT, Bacanu SA, Kendler KS. A genome-wide polygenic atlas of the phenome in emerging adulthood. Under review
Hancock L, Su J, McGann A, Alshagra M, Ericson R, Niazi Z, Dick DM*, Adkins A*. Evaluation of the impact of campus-wide social norms marketing intervention on alcohol use perceptions, consumption and blackouts. Under review
Hawn SE, Lind, MJ, Conley A, Overstreet, CM, Kendler KS, Dick DM, Amstadter AB. Effects of social support on the association between pre-college sexual assault and college onset victimization. Under review
Niazi Z, Dick DM, Adkins A, Cooke M. The influence of parenting styles on alcohol and nicotine drug use among university students. Under review
Overstreet C, Hawn SE, Conley A, Kendler KS, Dick DM, Amstadter AB. Prevalence and predictors of physical assault among a college sample. Under Review
Webb BT, Edwards AC, Wolen AR, Salvatore JE, Aliev F, Riley BP, Sun C, Vernell SW, Kitchen JN, Pedersen KA, Adkins A, Cooke M, Savage JE, Neale Z, Cho SB, Dick DM, Kendler KS. Genetic influences on normative and problematic alcohol use in a population-based sample of college students. Under Review
Do EK, Prom-Wormley EC, Fuemmeler BF, Dick DM, Kendler KS & Maes HH. Associations Between Initial Experiences with Nicotine, Recent Tobacco Use, and Dependence. Under review
Williams K, Thomas NS, Adkins AE, Dick DM. Perception of peer drinking and access to alcohol mediate the effect of residence status on alcohol consumption. Under review
Neale ZE, Salvatore JE, Cooke ME, Savage JE, Aliev F, Donovan KK, Hancock L, Dick DM. The utility of a brief web-based prevention intervention as a universal approach for risky alcohol use in college students: evidence of moderation by family history. Under review
Hawn SE, Sheerin CM, Webb BT, Peterson RE, Do E, Dick, DM, Kendler KS, Bacanu SA, Amstadter AB. Replication of the interaction of PRKG1 and trauma exposure on alcohol misuse in an independent, African American sample. Under review
Savage JE, Jansen PR, Stringer S, et al. GWAS meta-analysis identifies new genes and functional links to intelligence (N=279,930). Under review.