Reinforcing efficacy moderates the relationship between impulsivity-related traits and alcohol use

Effects of Sunday Liquor Sales Legalization on Alcohol Policy Attitudes and Alcohol Purchasing Behavior

We examined how legalization of Sunday alcohol sales relates to attitudes towards Sunday sales, and how both attitudes and alcohol consumption patterns relate to Sunday alcohol purchasing. A total of 1,384 adults of legal drinking age completed a survey one year post-legalization of Sunday sales. A majority of respondents (51%) were supportive of Sunday sales legalization both before and after legalization. People were more likely to support Sunday sales legalization if they reported binge drinking (PR: 2.19; CI: 1.51 3.18). Following Sunday sales legalization, 59% of participants reported purchasing alcohol in Minnesota on Sunday. Binge drinking (PR: 1.39; CI: 1.27, 1.52) or supporting Sunday sales legalization (PR: 1.85; CI: 1.56, 2.17) were associated with higher likelihood of purchasing alcohol on Sunday. Legalizing Sunday sales may have increased access to alcohol for people with more unhealthy drinking behaviors.

Concurrent validity of the Alcohol Purchase Task for measuring the reinforcing efficacy of alcohol: an updated systematic review and meta-analysis

BACKGROUND AND AIMS

An early meta-analysis testing the concurrent validity of the Alcohol Purchase Task (APT), a measure of alcohol's relative reinforcing value, reported mixed associations, but predated a large number of studies. This systematic review and meta-analysis sought to: (1) estimate the relationships between trait-based alcohol demand indices from the APT and multiple alcohol indicators, (2) test several moderators and (3) analyze small study effects.

METHODS

A meta-analysis of 50 cross-sectional studies in four databases (n = 18 466, females = 43.32%). Sex, year of publication, number of APT prices and index transformations (logarithmic, square root or none) were considered as moderators. Small study effects were examined by using the Begg-Mazumdar, Egger's and Duval & Tweedie's trim-and-fill tests. Alcohol indicators were quantity of alcohol use, number of heavy drinking episodes, alcohol-related problems and hazardous drinking. APT indices were intensity (i.e. consumption at zero cost), elasticity (i.e. sensitivity to increases in costs), O_max (i.e. maximum expenditure), P_max (i.e. price associated to O_max ) and breakpoint (i.e. price at which consumption ceases).

RESULTS

All alcohol demand indices were significantly associated with all alcohol-related outcomes (r = 0.132-0.494), except P_max , which was significantly associated with alcohol-related problems only (r = 0.064)_. The greatest associations were evinced between intensity in relation to alcohol use, hazardous drinking and heavy drinking and between O_max and alcohol use. All the tested moderators emerged as significant moderators. Evidence of small-study effects was limited.

CONCLUSIONS

The Alcohol Purchase Task appears to have concurrent validity in alcohol research. Intensity and O_max are the most relevant indices to account for alcohol involvement.

Behavioral economic demand assessments in the addictions

Behavioral economics in the addictions is the application of both economics and psychology to study multifaceted components of substance use decision-making behavior. One such component is demand: the relative value of a substance for a user (i.e., the association between drug use and cost). The degree to which a user values a substance can be measured via performance on hypothetical purchase tasks which replicate drug purchase and consumption. Demand has been evaluated across substances, including alcohol, marijuana, tobacco, and alternative tobacco products. Recent advances in the study of demand have greatly improved the assessment of drug value, including application to novel products, selection of optimal task unit, assessment of demand in naïve or potential future users, and the importance of instructional set specificity.

Using behavioral economic variables to predict future alcohol use in a crowdsourced sample

BACKGROUND

Theoretical perspectives at the intersection of behavioral economics and operant theory have resulted in numerous advances for addiction science. Three mechanisms (i.e. behavioral economic demand [consumption-price relationships], delay discounting [reinforcer devaluation with delay], and proportionate alcohol-related reinforcement [relative reinforcement attributable to alcohol]) are proposed to contribute to problematic alcohol use. Limited research has evaluated the unique contribution of these mechanisms for predicting future alcohol consumption.

AIM

The purpose of this study was to evaluate the predictive relationship between these mechanisms and self-reported alcohol use frequency, quantity, and severity.

METHODS

Participants (n=223) sampled from the crowdsourcing website Amazon Mechanical Turk completed a survey containing behavioral economic measures. Weekly reports of daily alcohol use were then collected for 18 weeks. Unadjusted and adjusted models determined the association between behavioral economic variables and alcohol use.

RESULTS/OUTCOMES

Behavioral economic measures were associated with alcohol and soda use at baseline in a stimulus-selective manner (e.g. alcohol demand associated with alcohol, but not soda, variables). Predictive models adjusted for Alcohol Use Disorder Identification Test scores indicated that increased proportionate alcohol-related reinforcement and behavioral economic demand were uniquely and incrementally associated with frequency (e.g. adjusted odds ratio (AOR)=5.54 for proportionate alcohol-related reinforcement, p<0.05) and quantity-severity measures (e.g. AOR=7.58 for alcohol demand intensity, p<0.001), respectively. Test-retest reliability was generally acceptable (r_xx=0.42-0.76) with the exception of proportionate alcohol-related reinforcement (r_xx=0.29).

CONCLUSION/INTERPRETATION

These findings indicate the unique, predictive, and incremental validity of behavioral economic measures for evaluating future alcohol consumption, supporting their continued use in addiction science research.

Understanding alcohol motivation using the alcohol purchase task: A methodological systematic review

BACKGROUND

The Alcohol Purchase Task (APT) is a behavioral economic assessment of alcohol demand (i.e., motivation for consumption during escalating levels of response cost) using simulated marketplace survey techniques. While the APT is often used and widely cited, to date, there has yet to be a systematic review elucidating the variability in administering and analyzing the APT. The purpose of the current paper is to address this knowledge gap in the literature by cataloging the various purchase task methodologies and providing recommendations and future areas of inquiry.

METHODS

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology was utilized (Prospero: No. CRD42017072159). Searches through Google Scholar, PsychINFO, PubMed, and SpringerLink databases identified 47 empirical articles referencing the use of an APT and published through the year 2016. Articles were coded for demographic and procedural characteristics, structural characteristics of the APT itself, and characteristics of data analysis.

RESULTS

Results indicate substantial variation within categories and suggest that there is no standard approach to administering the APT or analyzing the responses generated from it. The results underscore the need for researchers to report as much information as possible related to administration, instructions, price structuring, and analytical approach, as we found that many articles did not provide these details.

CONCLUSION

Enhancing the transparency of APT methods and analyses in published reports will aid in reproducibility as well as future meta-analytic studies of alcohol demand that could lead to the development of best-practice recommendations for this procedure.

Neuroimaging, neuromodulation, and population health: the neuroscience of chronic disease prevention

Preventable chronic diseases are the leading cause of death in the majority of countries throughout the world, and this trend will continue for the foreseeable future. The potential to offset the social, economic, and personal burdens associated with such conditions depends on our ability to influence people's thought processes, decisions, and behaviors, all of which can be understood with reference to the brain itself. Within the health neuroscience framework, the brain can be viewed as a predictor, mediator, moderator, or outcome in relation to health-related phenomena. This review explores examples of each of these, with specific reference to the primary prevention (i.e., prevention of initial onset) of chronic diseases. Within the topic of primary prevention, we touch on several cross-cutting themes (persuasive communications, delay discounting of rewards, and self-control), and place a special focus on obesity as a disorder influenced by both eating behavior and exercise habits.

Examination of approach and avoidance inclinations on the reinforcing value of alcohol

Although behavioral economics tends to focus on environmental factors (i.e., price, availability) that act to influence valuation of alcohol, recent research has begun to address how motivational and cognitive factors influence an individual's demand for alcohol. Motivational states, including craving, are one possible mechanism underlying the value based decision making that demand represents. Using a multidimensional model of craving (Ambivalence Model of Craving), the current study examined the relationships between indices of alcohol demand (i.e., reinforcing value of alcohol) and craving (i.e., approach inclinations), and the ways in which competing desires moderate that relationship (i.e., avoidance inclinations). Individuals who reported consuming alcohol in the past month were recruited for the study using Amazon's Mechanical Turk. A total of 529 participants (mean age=33.03years, SD=8.85) completed a series of surveys assessing their drinking behavior and other alcohol-related measures. Multiple regression analyses indicated that while approach significantly predicted intensity (i.e., consumption at zero cost), O_max (i.e., the maximum alcohol expenditure) and breakpoint (i.e., the first price that seizes consumption), avoidance moderated the relationship between approach and O_max and breakpoint. Specifically, follow up analyses demonstrated that higher avoidance inclinations attenuated the effect of approach inclinations on these demand indices. Finally, despite conceptual overlap between approach, avoidance, and alcohol demand, regression analyses indicated that these constructs account for unique variance in alcohol outcomes. These results illustrate the importance of considering the effects of both approach and avoidance inclinations on an individual's valuation of alcohol.

Comparing exponential and exponentiated models of drug demand in cocaine users

Drug purchase tasks provide rapid and efficient measurement of drug demand. Zero values (i.e., prices with zero consumption) present a quantitative challenge when using exponential demand models that exponentiated models may resolve. We aimed to replicate and advance the utility of using an exponentiated model by demonstrating construct validity (i.e., association with real-world drug use) and generalizability across drug commodities. Participants (N = 40 cocaine-using adults) completed Cocaine, Alcohol, and Cigarette Purchase Tasks evaluating hypothetical consumption across changes in price. Exponentiated and exponential models were fit to these data using different treatments of zero consumption values, including retaining zeros or replacing them with 0.1, 0.01, or 0.001. Excellent model fits were observed with the exponentiated model. Means and precision fluctuated with different replacement values when using the exponential model but were consistent for the exponentiated model. The exponentiated model provided the strongest correlation between derived demand intensity (Q0) and self-reported free consumption in all instances (Cocaine r = .88; Alcohol r = .97; Cigarette r = .91). Cocaine demand elasticity was positively correlated with alcohol and cigarette elasticity. Exponentiated parameters were associated with real-world drug use (e.g., weekly cocaine use) whereas these correlations were less consistent for exponential parameters. Our findings show that selection of zero replacement values affects demand parameters and their association with drug-use outcomes when using the exponential model but not the exponentiated model. This work supports the adoption of the exponentiated demand model by replicating improved fit and consistency and demonstrating construct validity and generalizability. (PsycINFO Database Record

Deficits in Access to Reward Are Associated with College Student Alcohol Use Disorder

BACKGROUND

Reward deprivation has been implicated in major depressive disorder and severe substance abuse, but its potential relation to alcohol use disorder (AUD) symptoms in non-treatment-seeking young adult drinkers is less clear. Depression is often comorbid with alcohol misuse, so relations of AUD with reward deprivation might be due in part to the presence of depressive symptoms in young adults. Behavioral economic theory views addiction as a state that is related in part to deficits in drug-free rewards, and therefore requires an investigation into whether reward deprivation has a direct relation to alcohol misuse that is, at least partially, independent of mood.

METHODS

This study evaluates the contribution of 2 facets of reward deprivation (reward availability and experience) to alcohol use, AUD symptoms, and depression in a sample of young adult heavy episodic drinkers. Data were collected from 392 undergraduates (60.4% female, 85.1% Caucasian) who reported recent heavy drinking (83.7% with at least 1 AUD symptom).

RESULTS

Low reward availability (environmental suppression) was significantly associated with both DSM-5 AUD symptoms and alcohol-related problems after controlling for age, gender, depressive symptomatology, and drinking level.

CONCLUSIONS

This study provides support for behavioral economic models that emphasize reward deprivation as a unique risk factor for AUD that is independent of mood and drinking level. Limited access to natural rewards may be a risk and/or maintaining factor for AUD symptoms in college student drinkers.

Reinforcer pathologies: Predicting alcohol related problems in college drinking men and women

BACKGROUND

Alcohol use in college is common, and problematic consequences of alcohol may affect college men and women differently. Approaches within behavioral economics have been used to improve our understanding of alcohol use in college students.

METHODS

The current study assessed relations between college students' delay discounting, demand for alcohol, and alcohol problems as measured by the Young Adult Alcohol Consequences Questionnaire (YAACQ). In this study, 80 college drinkers completed a monetary choice questionnaire that assessed delay discounting of money, a novel beer choice questionnaire that evaluated delay discounting of beer, and an alcohol purchase task that measured demand for alcohol.

RESULTS

Behavioral economic measures associated with the reinforcer pathologies model (i.e., demand and discounting) predicted alcohol consequences as measured by the YAACQ. For men, these significant predictor variables included money discounting, beer discounting, and intensity of alcohol demand, whereas for women money discounting and essential value were significant predictors.

CONCLUSIONS

These findings highlight the utility of the reinforcer pathologies approach for the study of alcohol use and the importance of considering gender differences in examining college drinking.

Validity of the alcohol purchase task: a meta-analysis

BACKGROUND AND AIMS

Behavioral economists assess alcohol consumption as a function of unit price. This method allows construction of demand curves and demand indices, which are thought to provide precise numerical estimates of risk for alcohol problems. One of the more commonly used behavioral economic measures is the Alcohol Purchase Task (APT). Although the APT has shown promise as a measure of risk for alcohol problems, the construct validity and incremental utility of the APT remain unclear. This paper presents a meta-analysis of the APT literature.

METHODS

Sixteen studies were included in the meta-analysis. Studies were gathered via searches of the PsycInfo, PubMed, Web of Science and EconLit research databases. Random-effects meta-analyses with inverse variance weighting were used to calculate summary effect sizes for each demand index-drinking outcome relationship. Moderation of these effects by drinking status (regular versus heavy drinkers) was examined. Additionally, tests of the incremental utility of the APT indices in predicting drinking problems above and beyond measuring alcohol consumption were performed.

RESULTS

The APT indices were correlated in the expected directions with drinking outcomes, although many effects were small in size. These effects were typically not moderated by the drinking status of the samples. Additionally, the intensity metric demonstrated incremental utility in predicting alcohol use disorder symptoms beyond measuring drinking.

CONCLUSIONS

The Alcohol Purchase Task appears to have good construct validity, but limited incremental utility in estimating risk for alcohol problems.

The Behavioral Economics and Neuroeconomics of Alcohol Use Disorders

BACKGROUND

Behavioral economics and neuroeconomics bring together perspectives and methods from psychology, economics, and cognitive neuroscience to understand decision making and choice behavior. Extending an operant behavioral theoretical framework, these perspectives have increasingly been applied to understand the alcohol use disorders (AUDs), and this review surveys the theory, methods, and findings from this approach. The focus is on 3 key behavioral economic concepts: delay discounting (i.e., preferences for smaller immediate rewards relative to larger delayed rewards), alcohol demand (i.e., alcohol's reinforcing value), and proportionate alcohol-related reinforcement (i.e., relative amount of psychosocial reinforcement associated with alcohol use).

FINDINGS

Delay discounting has been linked to AUDs in both cross-sectional and longitudinal studies and has been investigated cross-sectionally using neuroimaging. Alcohol demand and proportionate alcohol-related reinforcement have both been robustly associated with drinking and alcohol misuse cross-sectionally, but not over time. Both have also been found to predict treatment response to brief interventions. Alcohol demand has also been used to enhance the measurement of acute motivation for alcohol in laboratory studies. Interventions that focus on reducing the value of alcohol by increasing alternative reinforcement and response cost have been found to be efficacious, albeit in relatively small numbers of randomized controlled trials (RCTs). Mediators and moderators of response to these interventions have not been extensively investigated.

FUTURE DIRECTIONS

The application of behavioral economics and neuroeconomics to AUDs has given rise to an extensive body of empirical work, although significant gaps in knowledge remain. In particular, there is a need for more longitudinal investigations to clarify the etiological roles of these behavioral economic processes, especially alcohol demand and proportionate alcohol reinforcement. Additional RCTs are needed to extend and generalize the findings for reinforcement-based interventions and to investigate mediators and moderators of treatment success for optimization. Applying neuroeconomics to AUDs remains at an early stage and has been primarily descriptive to date, but has high potential for important translational insights into the future. The same is true for using these behavioral economic indicators to understand genetic influences on AUDs.

Further validation of a marijuana purchase task

BACKGROUND

A valid measure of the relative economic value of marijuana is needed to characterize individual variation in the drug's reinforcing value and inform evolving national marijuana policy. Relative drug value (demand) can be measured via purchase tasks, and demand for alcohol and cigarettes has been associated with craving, dependence, and treatment response. This study examined marijuana demand with a marijuana purchase task (MPT).

METHODS

The 22-item self-report MPT was administered to 99 frequent marijuana users (37.4% female, 71.5% marijuana use days, 15.2% cannabis dependent).

RESULTS

Pearson correlations indicated a negative relationship between intensity (free consumption) and age of initiation of regular use (r=-0.34, p<0.001), and positive associations with use days (r=0.26, p<0.05) and subjective craving (r=0.43, p<0.001). Omax (maximum expenditure) was positively associated with use days (r=0.29, p<0.01) and subjective craving (r=0.27, p<0.01). Income was not associated with demand. An exponential demand model provided an excellent fit to the data across users (R(2)=0.99). Group comparisons based on presence or absence of DSM-IV cannabis dependence symptoms revealed that users with any dependence symptoms showed significantly higher intensity of demand and more inelastic demand, reflecting greater insensitivity to price increases.

CONCLUSIONS

These results provide support for construct validity of the MPT, indicating its sensitivity to marijuana demand as a function of increasing cost, and its ability to differentiate between users with and without dependence symptoms. The MPT may denote abuse liability and is a valuable addition to the behavioral economic literature. Potential applications to marijuana pricing and tax policy are discussed.

Alcohol Consumption in Healthy OPRM1 G Allele Carriers and Its Association with Impulsive Behavior

AIMS

A link between alcohol use disorders (AUD) and impulsivity is well established. As there is evidence for the heritability of AUD, the investigation of the underlying genetic disposition for both conditions is an important issue. An association between AUD and a coding single nucleotide polymorphism (SNP) (rs1799971 encoding an Asn40Asp amino acid substitution, A118G) within the µ-opioid receptor 1 gene (OPRM1) has been reported. Therefore we tested the association between the OPRM1 A118G polymorphism and drinking as well as impulsive behavior in social drinkers.

METHODS

A total of 214 healthy male social drinkers were recruited. Each participant was genotyped for the OPRM1 A118G variant. Alcohol use was assessed with items of the Alcohol Use Disorders Identification Test (AUDIT). Impulsivity was assessed using the UPPS impulsive behavior scale. For statistical analyses, we considered correlations, t-tests and ordinal regression models using SPSS V21.

RESULTS

In total, 49 out of 214 participants were carriers of the OPRM1 118G allele. On average the OPRM1 118G carriers showed a slightly higher propensity for alcohol drinking. Higher drinking frequency among the G allele carriers was linked with higher urgency and perseveration subscores of impulsivity.

CONCLUSION

Our results suggest a genetically influenced higher propensity for alcohol drinking among social drinkers carrying the 118G allele of the OPRM1 gene. The positive correlation between urgency and a higher drinking frequency among the OPRM1 118G hint towards a functional meaning of the opioid system in the regulation of impulsivity.

The behavioral economics of substance use disorders: reinforcement pathologies and their repair

The field of behavioral economics has made important inroads into the understanding of substance use disorders through the concept of reinforcer pathology. Reinforcer pathology refers to the joint effects of (a) the persistently high valuation of a reinforcer, broadly defined to include tangible commodities and experiences, and/or (b) the excessive preference for the immediate acquisition or consumption of a commodity despite long-term negative outcomes. From this perspective, reinforcer pathology results from the recursive interactions of endogenous person-level variables and exogenous environment-level factors. The current review describes the basic principles of behavioral economics that are central to reinforcer pathology, the processes that engender reinforcer pathology, and the approaches and procedures that can repair reinforcement pathologies. The overall goal of this review is to present a new understanding of substance use disorders as viewed by recent advances in behavioral economics.

Impulsivity: four ways five factors are not basic to addiction

Several impulsivity-related models have been applied to understanding the vulnerability to addiction. While there is a growing consensus that impulsivity is multifaceted, debate continues as to the precise number of facets and, more critically, which are most relevant to explaining the addiction-risk profile. In many ways, the current debate mirrors that which took place in the personality literature in the early 1990s (e.g., Eysenck's 'Big Three' versus Costa and McCrae's 'Big Five'). Indeed, many elements of this debate are relevant to the current discussion of the role of impulsivity in addictive behavior. Specifically, 1) the use of factor analysis as an atheoretical 'truth-grinding machine'; 2) whether additional facets add explanatory power over fewer; 3) the delineation of specific neurocognitive pathways from each facet to addictive behaviors, and; 4) the relative merit of 'top-down' versus 'bottom-up' approaches to the understanding of impulsivity. Ultimately, the utility of any model of impulsivity and addiction lies in its heuristic value and ability to integrate evidence from different levels of analysis. Here, we make the case that theoretically-driven, bottom-up models proposing two factors deliver the optimal balance of explanatory power, parsimony, and integration of evidence.

A behavioral economic approach to assessing demand for marijuana

In the United States, marijuana is the most commonly used illicit drug. Its prevalence is growing, particularly among young adults. Behavioral economic indices of the relative reinforcing efficacy (RRE) of substances have been used to examine the appeal of licit (e.g., alcohol) and illicit (e.g., heroin) drugs. The present study is the first to use an experimental, simulated purchasing task to examine the RRE of marijuana. Young-adult (M age = 21.64 years) recreational marijuana users (N = 59) completed a computerized marijuana purchasing task designed to generate demand curves and the related RRE indices (e.g., intensity of demand-purchases at lowest price; Omax-max. spent on marijuana; Pmax-price at which marijuana expenditure is max). Participants "purchased" high-grade marijuana across 16 escalating prices that ranged from $0/free to $160/joint. They also provided 2 weeks of real-time, ecological momentary assessment reports on their marijuana use. The purchasing task generated multiple RRE indices. Consistent with research on other substances, the demand for marijuana was inelastic at lower prices but became elastic at higher prices, suggesting that increases in the price of marijuana could lessen its use. In regression analyses, the intensity of demand, Omax, and Pmax, and elasticity each accounted for significant variance in real-time marijuana use. These results provide support for the validity of a simulated marijuana purchasing task to examine marijuana's reinforcing efficacy. This study highlights the value of applying a behavioral economic framework to young-adult marijuana use and has implications for prevention, treatment, and policies to regulate marijuana use.

Behavioral economic measures of alcohol reward value as problem severity indicators in college students

The aims of the current study were to examine the associations among behavioral economic measures of alcohol value derived from 3 distinct measurement approaches, and to evaluate their respective relations with traditional indicators of alcohol problem severity in college drinkers. Five behavioral economic metrics were derived from hypothetical demand curves that quantify reward value by plotting consumption and expenditures as a function of price, another metric measured proportional behavioral allocation and enjoyment related to alcohol versus other activities, and a final metric measured relative discretionary expenditures on alcohol (RDEA). The sample included 207 heavy-drinking college students (53% female) who were recruited through an on-campus health center or university courses. Factor analysis revealed that the alcohol valuation construct comprises 2 factors: 1 factor that reflects participants' levels of alcohol price sensitivity (demand persistence), and a second factor that reflects participants' maximum consumption and monetary and behavioral allocation toward alcohol (amplitude of demand). The demand persistence and behavioral allocation metrics demonstrated the strongest and most consistent multivariate relations with alcohol-related problems, even when controlling for other well-established predictors. The results suggest that behavioral economic indices of reward value show meaningful relations with alcohol problem severity in young adults. Despite the presence of some gender differences, these measures appear to be useful problem indicators for men and women.

Smokers report greater demand for alcohol on a behavioral economic purchase task

OBJECTIVE

Cigarette smokers have higher levels of alcohol consumption than nonsmokers and poorer response to alcohol treatment. It is possible that the greater severity of alcohol problems observed in smokers reflects a greater susceptibility to alcohol-related reinforcement. The present study used a behavioral economic purchase task to investigate whether heavy drinking smokers would have greater demand for alcohol than heavy drinking nonsmokers.

METHOD

Participants were 207 college students who reported at least one heavy drinking episode in the past month. Of the 207 participants, 33.2% (n = 67) reported smoking cigarettes at least 1 day in the past month. Participants completed the hypothetical alcohol purchase task, a simulation task that asked them to report how many drinks they would purchase at varying price increments.

RESULTS

After the participants' reported alcohol consumption, gender, alcohol problems, and depression were controlled for, analyses of covariance revealed that heavy drinking smokers had significantly greater reported maximum alcohol expenditures (Omax), greater maximum inelastic price (Pmax), and higher breakpoint values (first price suppressing consumption to zero).

CONCLUSIONS

College student heavy drinkers who also smoke cigarettes exhibit increased demand for alcohol. Smokers in this high-risk developmental stage may thus be less sensitive to price and other contingencies that would otherwise serve to modulate drinking and may require more intensive intervention approaches.

Energy drink consumption among young Australian adults: associations with alcohol and illicit drug use

BACKGROUND

Energy drinks are becoming increasingly popular among young people. The purpose of this study was to determine the prevalence of energy drink consumption and its associations with socio-demographic characteristics, alcohol, cigarette and illicit drug use in a population-based sample of young adults participating in the Western Australian Pregnancy Cohort (Raine) Study.

METHODS

We used self-administered questionnaires to assess energy drink consumption patterns, alcohol intake, cigarette and illicit drug use at the 20-year cohort follow-up. Data was also collected on socio-demographics, physical activity, body mass index (BMI) and dietary intake. Our sample included 1234 participants (47% male, mean age 20 ± 0.5 years). We considered energy-drink consumption as a categorical (users versus non-users) variable.

RESULTS

Overall, 48% of participants consumed energy drinks at least once per month, with an average intake of 1.31 ± 0.75 cans per day amongst energy drink users. The most significant correlates of energy drink use were being in part-time or full-time employment, being male, being a cigarette smoker, having heavier alcoholic spirit consumption patterns and being an ecstasy user (all p<0.05). No significant associations were observed with BMI or dietary intake.

CONCLUSIONS

Australian energy drink users tend to have heavier alcohol consumption patterns be a cigarette smoker and use illicit drugs relative to non-users. More research is needed regarding the health risks associated with energy drink use in young adults, including their possible role in the development of substance abuse problems.

Examining a curvilinear model of readiness to change and alcohol consumption

Research examining the relationship between readiness to change and alcohol consumption among college students is inconsistent. The purpose of the present study was to extend these findings, using two different measures of readiness to change. We hypothesized a curvilinear effect would occur such that the relationship between readiness to change and alcohol use would be relatively low for students low and high on readiness to change, whereas the relationship would be relatively high for those with moderate levels of readiness to change. Data were collected from two studies: Study 1 consisted of 263 undergraduate students and Study 2 consisted of 245 undergraduates participating in either intercollegiate or recreational athletics at three US universities. In Study 1, we examined the association between both linear and quadratic scores on a readiness to change measure and alcohol use. In Study 2, we examined the relationship between scores on a stage of change measure that included subscales indicative of different levels of readiness to change and alcohol use. The pattern of relationships supported the existence of an effect where the highest levels of alcohol use occurred among those with scores representing moderate levels of readiness to change.

Interrelationships among individual differences in alcohol demand, impulsivity, and alcohol misuse

An Alcohol Purchase Task (APT) is a novel behavioral economic measure for characterizing the incentive value of alcohol to an individual (i.e., alcohol demand). Individual differences in alcohol demand have been associated with a number of alcohol-related outcomes and the current investigation sought to extend these previous findings in a number of ways. The goals of the study were: (a) to examine the relationship between alcohol demand and alcohol misuse in a large sample of community adults; (b) to examine sex differences in alcohol demand; and, (c) to examine the relationship between alcohol demand and impulsive personality traits, both in general and as moderating variables. Participants (N = 720; 39% female) were adult smokers who reported drinking in the last year and were recruited from the community at large. All four behavioral economic indices of demand from the APT were significantly associated with alcohol misuse, with Omax and intensity uniquely associated in combined analyses. Males exhibited significantly higher demand, but these differences were largely eliminated after adjusting for drinks per week and other covariates. Trait levels of urgency, sensation-seeking and lack of premeditation were significantly associated with intensity and urgency was associated with Omax, but no moderating relationships were present. The significant relationships between aspects of impulsivity and the demand indices may signify a common process underlying disinhibition and demand for alcohol. These findings further support the relationship between indices of alcohol demand and alcohol misuse and a link between demand and impulsivity. Methodological considerations and future directions are discussed.

Symptoms of depression and PTSD are associated with elevated alcohol demand

BACKGROUND

Behavioral economic demand curves measure individual differences in motivation for alcohol and have been associated with problematic patterns of alcohol use, but little is known about the variables that may contribute to elevated demand. Negative visceral states have been theorized to increase demand for alcohol and to contribute to excessive drinking patterns, but little empirical research has evaluated this possibility. The present study tested the hypothesis that symptoms of depression and PTSD would be uniquely associated with elevated alcohol demand even after taking into account differences in typical drinking levels.

METHOD

An Alcohol Purchase Task (APT) was used to generate a demand curve measure of alcohol reinforcement in a sample of 133 college students (50.4% male, 64.4% Caucasian, 29.5% African-American) who reported at least one heavy drinking episode (5/4 or more drinks in one occasion for a man/woman) in the past month. Participants also completed standard measures of alcohol consumption and symptoms of depression and PTSD.

RESULTS

Regression analyses indicated that symptoms of depression were associated with higher demand intensity (alcohol consumption when price=0; ΔR(2)=.05, p=.002) and lower elasticity (ΔR(2)=.04, p=.03), and that PTSD symptoms were associated with all five demand curve metrics (ΔR(2)=.04-.07, ps<.05).

CONCLUSIONS

These findings provide support for behavioral economic models of addiction that highlight the role of aversive visceral states in increasing the reward value of alcohol and provide an additional theoretical model to explain the association between negative affect and problematic drinking patterns.

Do protective behavioral strategies moderate the relationship between negative urgency and alcohol-related outcomes among intercollegiate athletes?

OBJECTIVE

The purpose of this study was to examine the moderating effect of protective behavioral strategies on the relationship between negative urgency and alcohol outcomes.

METHOD

Participants were college students who endorsed participating in club/intramural or varsity athletics. The students (N = 234; 73.9% female) completed measures of negative urgency, protective behavioral strategies, alcohol use, and alcohol-related problems. Separate hierarchical multiple regression analyses were conducted for each subscale of the Protective Behavioral Strategies Scale to test for moderation.

RESULTS

Results indicated that protective behavioral strategies aimed at serious harm reduction moderated the relationship between negative urgency and alcohol use, whereas strategies aimed at avoiding excessive or rapid drinking moderated the relationship between negative urgency and alcohol-related problems. Strategies that involved planning drinking activities in advance did not moderate the relationship between negative urgency and alcohol outcomes.

CONCLUSIONS

The current investigation provides further evidence for the role of protective behavioral strategies against known risk factors for alcohol use and related problems. Further, the paper suggests that type of strategy used matters when attempting to mitigate the relationship between negative urgency and alcohol outcomes. Limitations and future directions are discussed.

Associations between energy drink consumption and alcohol use behaviors among college students

BACKGROUND

To explore associations between energy drink consumption and alcohol use among college students.

METHODS

Participants included 585 students (m age=18.7; 47.0% White, 21% Hispanic, 25% Asian, 7% other race/ethnicity; 56.0% female). Energy drink behaviors included past month and past week consumption. Alcohol use behaviors included past month and past two week consumption, as well as heavy drinking and quantity of alcohol consumed. Consumption of energy drinks mixed with alcohol was also measured. Linear and logistic regression analyses between energy drink consumption and alcohol use were run controlling for gender, age, and race/ethnicity.

RESULTS

For each one unit increase in past month (i.e., additional day used) energy drink use, the likelihood of past month alcohol use increased by 80%, heavy drinking by 80% and past month energy drinks mixed with alcohol use by 90%. Similar results were found for past week energy drink use. A positive relationship between energy drink use and quantity of alcohol consumed during a single episode of drinking was also found (p<0.001). Significant gender interactions between energy drink consumption and alcohol use as well as quantity of alcohol consumed were found, with relationships stronger among males than females. There were no significant interactions by race/ethnicity.

CONCLUSIONS

Energy drinks are readily available to students and pose potential health risks. Students who report greater energy drink consumption also consume more alcohol, are more likely to mix energy drinks and alcohol, and experience heavy episodes of drinking, which is problematic given the potential negative consequences of these drinks.