Mary E. Larimer's research while affiliated with University of Washington Seattle and other places

Motor vehicle crashes are a leading cause of death for young adults (YA) in the USA, and driving under the influence of alcohol (DUIA), cannabis (DUIC), and simultaneous use of both substances (DUIAC) are prominent risk factors. Trends in YA impaired driving behaviors after opening of cannabis retail stores have been understudied. We examined YA trends in DUIA, DUIC, and DUIAC from immediately prior through 5 years following the opening of cannabis retail outlets in Washington State (2014–2019). Differences in trends were assessed across age, sex, and urbanicity. Weighted logistic regressions assessed yearly change in prevalence of DUIA, DUIC, and DUIAC from 2014 to 2019, using annual statewide data from the Washington Young Adult Health Survey (n = 12,963; ages 18–25). Moderation of trends by age, sex, and urbanicity was assessed. Prevalence of DUIA decreased overall (AOR = 0.93, 95% CI 0.90, 0.97) and among drinkers (AOR = 0.95, 95% CI 0.91, 0.99) but remained at concerning levels in 2019 (10% overall; 16% among drinkers). Overall DUIC did not change significantly (AOR = 0.99, 95% CI 0.96, 1.03; 11% by 2019) but decreased among those who used cannabis (AOR = 0.91, 95% CI 0.86, 0.96; 33% by 2019). DUIAC decreased but not significantly (overall: AOR = 0.89, 95% CI 0.78, 1.01; those who used alcohol and cannabis: AOR = 0.84, 95% CI 0.74, 1.04). Prevalence of YA DUI remained concerning. Trends may reflect some success in reducing DUI, but additional detection and prevention are needed.

In recent years a fear of missing out (FOMO) on short-term monetary gains through speculative trading has been highlighted as a driving force of financial behaviors. Additionally, increasing evidence has likened speculative trading to gambling. The current study sought to determine whether financial FOMO is linked to stock market and cryptocurrency trading activities and problem gambling severity in both traditional gambling and financial trading domains, among a sample of 258 college students. Results of binomial regression and hurdle model analyses found that financial FOMO was linked to participation in stock market and cryptocurrency trading. Financial FOMO was also associated with problem gambling severity in traditional gambling and the presence of gambling problems in the stock market trading domain. Our results suggest that financial FOMO may be a salient risk factor of problem gambling in traditional gambling domains and, to a smaller degree, in the speculative trading domain among young adults.

Background Alcohol misuse among college students is a public health concern. Protective behavioral strategies (PBS) can be used before, during, after, or instead of drinking to reduce alcohol use and negative consequences, but findings on their utility at the aggregate level are mixed. Although recent work has provided important information on the performance of individual PBS items, it is limited by research designs that are cross‐sectional, do not examine consequences, or do not examine other important correlates, such as drinking motives. This study examines both the association between item‐level PBS and alcohol‐related negative consequences and the moderating effect of drinking motives longitudinally. Methods College students from two universities ( n = 200, 62.5% female, M age = 20.16) completed the Drinking Motives Questionnaire‐Revised, Protective Behavioral Strategies Survey, the Rutgers Alcohol Problem Index, and a measure of the quantity of alcohol use at baseline and 3‐month follow‐up. Generalized linear models were conducted to assess direct effects of item‐level PBS on alcohol‐related consequences and the moderating effects of drinking motives. Results Two PBS items were associated with fewer alcohol‐related consequences at follow‐up, and two items were associated with greater alcohol‐related consequences at follow‐up. Drinking motives differentially moderated associations between item‐level PBS and alcohol‐related consequences for a proportion in the sample. Enhancement motives moderated the greatest number of associations, followed by coping, conformity, and social motives. Certain PBS (e.g., drink slowly, rather than gulp or chug) were moderated by several drinking motives, whereas other PBS items were not moderated by any motives. Conclusion Consistent with previous research, some item‐level PBS were associated longitudinally with increased negative consequences, and some were associated with decreased negative consequences. Drinking motives, particularly enhancement, moderated several item‐level PBS and consequence associations, suggesting that reasons for drinking may be important for understanding the associations between PBS strategies and alcohol‐related consequences.

College student cannabis use is at an all-time high. Although frequent heavy cannabis use is related to cannabis problems, perceived risk of cannabis use is rapidly decreasing. Yet, it is unknown whether specific domains of risk perceptions (general and domain-specific risk, risk to others and personal risk) are related to more cannabis use or related problems. Thus, among 130 undergraduates who reported past-month cannabis use, the present study conducted secondary analyses to test whether, for both perceived risk to others and perceived personal risk: (1) general perceived risk was associated with cannabis-related outcomes (i.e., use, negative consequences, cannabis use disorder (CUD) symptoms, motivation to change), (2) seven specific domains of perceived risk were related to cannabis outcomes, and (3) domain-specific perceived risk was related to cannabis use frequency. General perceived risk to others was negatively associated with cannabis use frequency whereas general perceived personal risk was positively associated with cannabis-related negative consequences, CUD symptoms, and importance and readiness to change. Greater legal and withdrawal/dependence risks were uniquely related to several outcomes (e.g., CUD symptoms). Participants who used cannabis frequently perceived more personal risk in most risk domains and less general risk to others than those who used infrequently. Findings suggest personal risk is an important component to consider when assessing perceived risk of cannabis use and focusing on both general and domain-specific risks may provide valuable insight for future prevention and intervention efforts.

Objective: Understanding transitions in nicotine and cannabis use has implications for prevention and efforts to reduce harmful use. Focusing on cross-substance associations, we examined how use of one substance was associated with year-to-year transitions in frequency of use of the other among young adults in the context of legalized nonmedical cannabis. Method: A statewide sample from Washington (N = 4,039; ages 18-25 at baseline) provided up to three years of annual data on past-month cannabis use and nicotine use (tobacco cigarettes and e-cigarettes/vaping). Manifest Markov models examined how use of each substance was associated with transitions in the other across categories of past-month no use, occasional use (1-19 days), and frequent use (20+ days). Results: Occasional and frequent nicotine use (vs. no use) predicted higher probability of transitioning from no cannabis use to occasional or frequent cannabis use and from occasional use to frequent use, while associations with cessation and de-escalation were inconsistent in direction, small in magnitude, and not statistically significant. Cannabis use positively predicted onset of nicotine use, and associations of cannabis use with escalation from occasional to frequent nicotine use, de-escalation in use, and cessation in use were small and inconsistent in direction. Conclusions: The findings corroborate prior research on cannabis and nicotine use as risk factors to address in prevention efforts. The findings do not provide strong support for prioritization of dual abstinence in efforts to encourage reductions in or cessation of cannabis or nicotine use among young adults.

Background: Research demonstrates that perceptions of others' attitudes toward drinking behaviors (injunctive norms) are strong predictors of alcohol consumption and problems. Personalized normative feedback (PNF) aims to reduce the discrepancy between one's perception of others' attitudes toward drinking and others' actual attitudes toward drinking. An implicit assumption of PNF is that self and (perceived) other attitudes toward drinking are aligned (thus, shifting one's perceptions of others' attitudes shifts one's own attitudes). However, there is minimal research on the extent to which alignment (or discrepancy) in self-other attitudes toward drinking is associated with alcohol-related outcomes. Methods: College students (N = 1,494; Mage = 20.11, 61.0% female, 66.4% White) who endorsed past-month heavy episodic drinking reported injunctive norms toward drinking on weekends, drinking daily, drinking to black out, and drinking and driving. Participants reported their perceptions of attitudes toward these drinking behaviors for three reference groups: close friends, typical university-affiliated peers, and parents. Outcomes included weekly drinking, alcohol problems, and alcohol-related risk. Results: Response surface analyses indicated that alignment in approval (versus alignment in disapproval) of drinking demonstrated a linear association with alcohol-related outcomes. Discrepancies in self-peer and self-parent attitudes were associated with alcohol-related outcomes and one's own attitudes (versus one's ratings of others' attitudes) of drinking were more strongly associated with outcomes. Conclusions: Results provide evidence of how self-other discrepancies in attitudes toward drinking are associated with alcohol-related outcomes. Future work is needed to test whether self-other discrepancies in attitudes toward drinking impacts response to norms-based interventions.

Commensurate measures of alcohol-related consequences across countries and cultures are critical for addressing the global burden of hazardous alcohol use. The Rutgers Alcohol Problem Index (RAPI), developed and validated in the United States, is a popular measure of alcohol problems. This study examined measurement invariance of the RAPI across samples of U.S. and Swedish high school seniors. Latent mean differences in alcohol problems across countries and differences in associations between alcohol problems with alcohol use and protective behavioral strategies (PBS) were also examined. The RAPI was scalar invariant. Swedish students reported fewer problems than U.S. students (latent mean difference = -0.19, p = .047). In both samples, the RAPI was positively correlated with alcohol use frequency and quantity (ps < .001), and negatively correlated with PBS use (ps < .05). Overall, the RAPI demonstrated measurement invariance, and we found evidence for its validity across samples of U.S. and Swedish high school seniors.

Purpose: Alcohol- and cannabis-impaired driving behaviors remain a public health concern especially among young adults (i.e., ages 18-25). Limited updates to prevention efforts for these behaviors may be due, in part, to limited understanding of malleable psychosocial predictors. The current study assessed associations between perceived injunctive norms (i.e., acceptability) of driving under the influence of alcohol (DUI-A) and cannabis (DUI-C), and riding with a driver under the influence of alcohol (RWI-A) and cannabis (RWI-C) in Washington State young adults. Methods: Participants included 1,941 young adults from the 2019 cohort of the Washington Young Adult Health Survey. Weighted logistic regressions assessed the associations between peer injunctive norms and impaired driving-related behaviors. Results: A weighted total of 11.5% reported DUI-A, 12.4% DUI-C, 10.9% RWI-A, and 20.9% RWI-C at least once in the past 30 days. Overlap between the outcomes was observed, indicating some young adults had engaged in multiple impaired driving-related behaviors. After controlling for substance use frequency, weighted logistic regressions indicated more positive perceived injunctive norms were associated with nearly 2 ½ times higher odds of DUI-A, 8 times higher odds of DUI-C, 4 times higher odds of RWI-A and six and a half times higher odds of RWI-C. Discussion: Results increase the understanding of how injunctive norms-a potentially malleable psychosocial factor-are associated with four impaired driving-related outcomes. Prevention programs that focus on assessing and addressing the norms of these outcomes individually and collectively, such as normative feedback interventions and media campaigns, may be helpful in reducing these behaviors.

Background: There is currently no format-independent method to determine delta-9-tetrahydrocannabinol (THC) in milligrams for self-report studies.Objectives: Validate self-report method for quantifying mg THC from commercially available cannabis products using product labeling, which includes both net weight and product potency.Methods: 53 adult cannabis users (24 M, 29F), 21-39 years of age (M = 28.38, SD = 4.15), were instructed to report daily use via a weekly survey for two consecutive weeks, provide product label photographs, abstain from use for 24 h, submit a urine sample and complete the Cannabis Use Disorder Identification Test - Revised (CUDIT-R) and the Marijuana Craving Questionnaire - Short Form (MCQ-SF). Milligrams of THC were determined by multiplying quantity of product used by its THC concentration. Urine was analyzed for the urine metabolite 11-nor-carboxy-THC (THC-COOH) via liquid chromatography mass spectroscopy. THC and THC-COOH values were log10 transformed prior to correlational analyses.Results: Median daily THC consumption was 102.53 mg (M = 203.68, SD = 268.13). Thirty-three (62%) of the 53 participants reported using two or more formats over the 2-week period. There was a significant positive correlation between log10 THC-COOH and log10 THC mg (r(41) = .59, p < .001), log10 THC mg and MCQ-SF score (r(41) = .59, p < .001), and log10 THC mg dose and CUDIT-R score, (r(41) = .39, p = .010).Conclusion: Our label-based methodology provides consumption information across all modalities of cannabis use in standard units that can be combined across products for calculation of dose. It is a viable and valid method for quantifying mg of THC consumed and can be utilized in any region where cannabis is legal, and labeling is regulated.