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

A behavioral economic analysis of texting while driving: Delay discounting processes

The purpose of the present study was to examine an impulsive decision-making process underlying texting while driving from a behavioral economic perspective. A sample of 108 college students completed a novel discounting task that presented participants with a hypothetical scenario in which, after receiving a text message while driving, they rated the likelihood of replying to a text message immediately versus waiting to reply for a specific period of time. Participants also completed a delay discounting task in which they made repeated hypothetical choices between obtaining a larger amount of money available after a delay and an equal or lesser amount of money available immediately. The results show that the duration of the delay is a critical variable that strongly determines whether participants choose to wait to reply to a text message, and that the decrease in the likelihood of waiting as a function of delay is best described by a hyperbolic delay discounting function. The results also show that participants who self-reported higher frequency of texting while driving discounted the opportunity to reply to a text message at greater rates, whereas there was no relation between the rates of discounting of hypothetical monetary rewards and the frequency of texting while driving. The results support the conclusion that texting while driving is fundamentally an impulsive choice.

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.

Some current dimensions of the behavioral economics of health-related behavior change

Health-related behaviors such as tobacco, alcohol and other substance use, poor diet and physical inactivity, and risky sexual practices are important targets for research and intervention. Health-related behaviors are especially pertinent targets in the United States, which lags behind most other developed nations on common markers of population health. In this essay we examine the application of behavioral economics, a scientific discipline that represents the intersection of economics and psychology, to the study and promotion of health-related behavior change. More specifically, we review what we consider to be some core dimensions of this discipline when applied to the study health-related behavior change. Behavioral economics (1) provides novel conceptual systems to inform scientific understanding of health behaviors, (2) translates scientific understanding into practical and effective behavior-change interventions, (3) leverages varied aspects of behavior change beyond increases or decreases in frequency, (4) recognizes and exploits trans-disease processes and interventions, and (5) leverages technology in efforts to maximize efficacy, cost effectiveness, and reach. These dimensions are overviewed and their implications for the future of the field discussed.

A behavioral economic perspective on smoking persistence in serious mental illness

Serious mental illness (SMI) is associated with disproportionately high rates of cigarette smoking. The identification of factors that contribute to persistent smoking in people with SMI may lead to the development and adoption of tobacco control policies and treatment approaches that help these smokers quit. This commentary examines factors underlying smoking persistence in people with SMI from the perspective of behavioral economics, a discipline that applies economic principles to understanding drug abuse and dependence. Studies, conducted in the Northeastern US within the past 30years, that compare the reinforcing effects of nicotine and the costs of smoking in smokers with and without schizophrenia and depression are discussed, and interventions that may reduce the reinforcing efficacy of nicotine and increase the costs of smoking in people with SMI are described.

The behavioral economics of young adult substance abuse

Alcohol and drug use peaks during young adulthood and can interfere with critical developmental tasks and set the stage for chronic substance misuse and associated social, educational, and health-related outcomes. There is a need for novel, theory-based approaches to guide substance abuse prevention efforts during this critical developmental period. This paper discusses the particular relevance of behavioral economic theory to young adult alcohol and drug misuse, and reviews of available literature on prevention and intervention strategies that are consistent with behavioral economic theory. Behavioral economic theory predicts that decisions to use drugs and alcohol are related to the relative availability and price of both alcohol and substance-free alternative activities, and the extent to which reinforcement from delayed substance-free outcomes is devalued relative to the immediate reinforcement associated with drugs. Behavioral economic measures of motivation for substance use are based on relative levels of behavioral and economic resource allocation towards drug versus alternatives, and have been shown to predict change in substance use over time. Policy and individual level prevention approaches that are consistent with behavioral economic theory are discussed, including brief interventions that increase future orientation and engagement in rewarding alternatives to substance use. Prevention approaches that increase engagement in constructive future-oriented activities among young adults (e.g., educational/vocational success) have the potential to reduce future health disparities associated with both substance abuse and poor educational/vocational outcomes.

Behavioral economic indicators of drinking problem severity and initial outcomes among problem drinkers attempting natural recovery: a cross-sectional naturalistic study

BACKGROUND AND AIMS

Research using different behavioral economic (BE) and time perspective (TP) measures suggests that substance misusers show greater sensitivity to shorter-term contingencies than normal controls, but multiple measures have seldom been investigated together. This study evaluated the extent to which multiple BE and TP measures were associated with drinking problem severity, distinguished initial outcomes of natural recovery attempts and shared common variance. Hypotheses were (1) that greater problem severity would be associated with greater impulsivity and demand for alcohol and shorter TPs; and (2) that low-risk drinking would be associated with greater sensitivity to longer-term contingencies compared with abstinence.

DESIGN

Cross-sectional naturalistic field study.

SETTING

Southern United States.

PARTICIPANTS

Problem drinkers, recently resolved without treatment [n = 191 (76.44% male), mean age = 50.09 years] recruited using media advertisements.

MEASUREMENTS

Drinking practices, dependence levels and alcohol-related problems prior to stopping problem drinking were assessed during structured field interviews. Measures included the Zimbardo Time Perspective Inventory; BE analogue choice tasks [delay discounting (DD), melioration-maximization (MM), alcohol purchase task (APT)]; and the Alcohol-Savings Discretionary Expenditure (ASDE) index, derived from real spending on alcohol and voluntary savings during the year before problem cessation.

FINDINGS

Measures of demand based on real (ASDE) and hypothetical (APT) spending on alcohol were associated with problem severity (Ps < 0.05), but DD, MM and TP measures were not. More balanced pre-resolution spending on alcohol versus saving for the future distinguished low-risk drinking from abstinent resolutions (ASDE odds ratio =5.59; P < 0.001). BE measures did not share common variance.

CONCLUSIONS

Two behavioral assessment tools that measure spending on alcohol, the Alcohol Purchase Task and the Alcohol-Savings Discretionary Expenditure index, appear to be reliable in assessing the severity of drinking problems. The ASDE index also may aid choices between low-risk and abstinent drinking goals.

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.

Alcohol-approach inclinations and drinking identity as predictors of behavioral economic demand for alcohol

Behavioral economic demand curve indices of alcohol consumption reflect decisions to consume alcohol at varying costs. Although these indices predict alcohol-related problems beyond established predictors, little is known about the determinants of elevated demand. Two cognitive constructs that may underlie alcohol demand are alcohol-approach inclinations and drinking identity. The aim of this study was to evaluate implicit and explicit measures of these constructs as predictors of alcohol demand curve indices. College student drinkers (N = 223, 59% female) completed implicit and explicit measures of drinking identity and alcohol-approach inclinations at 3 time points separated by 3-month intervals, and completed the Alcohol Purchase Task to assess demand at Time 3. Given no change in our alcohol-approach inclinations and drinking identity measures over time, random intercept-only models were used to predict 2 demand indices: Amplitude, which represents maximum hypothetical alcohol consumption and expenditures, and Persistence, which represents sensitivity to increasing prices. When modeled separately, implicit and explicit measures of drinking identity and alcohol-approach inclinations positively predicted demand indices. When implicit and explicit measures were included in the same model, both measures of drinking identity predicted Amplitude, but only explicit drinking identity predicted Persistence. In contrast, explicit measures of alcohol-approach inclinations, but not implicit measures, predicted both demand indices. Therefore, there was more support for explicit, versus implicit, measures as unique predictors of alcohol demand. Overall, drinking identity and alcohol-approach inclinations both exhibit positive associations with alcohol demand and represent potentially modifiable cognitive constructs that may underlie elevated demand in college student drinkers. (PsycINFO Database Record

Behavioral Economic Laboratory Research in Tobacco Regulatory Science

OBJECTIVES

Research that can provide a scientific foundation for the United States Food and Drug Administration (FDA) tobacco policy decisions is needed to inform tobacco regulatory policy. One factor that affects the impact of a tobacco product on public health is its intensity of use, which is determined, in part, by its abuse liability or reinforcing efficacy. Behavioral economic tasks have considerable utility for assessing the reinforcing efficacy of current and emerging tobacco products.

METHODS

This paper provides a narrative review of several behavioral economic laboratory tasks and identifies important applications to tobacco regulatory science.

RESULTS

Behavioral economic laboratory assessments, including operant self-administration, choice tasks and purchase tasks, can be used generate behavioral economic data on the effect of price and other constraints on tobacco product consumption. These tasks could provide an expedited simulation of the effects of various tobacco control policies across populations of interest to the FDA.

CONCLUSIONS

Tobacco regulatory research questions that can be addressed with behavioral economic tasks include assessments of the impact of product characteristics on product demand, assessments of the abuse liability of novel and potential modified risk tobacco products (MRTPs), and assessments of the impact of conventional and novel products in vulnerable populations.

The temporal window of valuation is constricted among adolescent smokers

Healthy decisions are associated with valuation of the future whereas unhealthy decisions are associated with devaluation of the future. Comparisons of future discounting of delayed rewards in adolescent smokers and non-smokers have been equivocal and past discounting of monetary gains has not been reported in adolescents. Here, adolescents completed future and past delay discounting tasks. A mixed-model analysis of covariance using a model with the lowest Bayesian Information Criterion revealed that adolescents discount the past more than the future and smokers discount more than non-smokers. These results suggest that adolescent smokers have a constricted temporal window, which may lead to disadvantageous decisions.

The latent structure of impulsivity: impulsive choice, impulsive action, and impulsive personality traits

RATIONALE

Impulsivity has been strongly linked to addictive behaviors, but can be operationalized in a number of ways that vary considerably in overlap, suggesting multidimensionality.

OBJECTIVE

This study tested the hypothesis that the latent structure among multiple measures of impulsivity would reflect the following three broad categories: impulsive choice, reflecting discounting of delayed rewards; impulsive action, reflecting ability to inhibit a prepotent motor response; and impulsive personality traits, reflecting self-reported attributions of self-regulatory capacity.

METHODS

The study used a cross-sectional confirmatory factor analysis of multiple impulsivity assessments. Participants were 1252 young adults (62 % female) with low levels of addictive behavior, who were assessed in individual laboratory rooms at the University of Chicago and the University of Georgia. The battery comprised a Delay (replace hyphen with space) Discounting Task, Monetary Choice Questionnaire, Conners' Continuous Performance Test, Go/NoGo Task, Stop Signal Task, Barratt Impulsiveness Scale, and the UPPS-P Impulsive Behavior Scale.

RESULTS

The hypothesized three-factor model provided the best fit to the data, although sensation seeking was excluded from the final model. The three latent factors were largely unrelated to each other and were variably associated with substance use.

CONCLUSIONS

These findings support the hypothesis that diverse measures of impulsivity can broadly be organized into three categories that are largely distinct from one another. These findings warrant investigation among individuals with clinical levels of addictive behavior and may be applied to understanding the underlying biological mechanisms of these categories.

Behavioral Activation Treatment for Smoking (BATS) in smokers with depressive symptomatology

Purpose

Cigarette smoking remains the primary preventable cause of mortality and morbidity globally. The overarching goal of the paper is to disseminate the Behavioral Activation Treatment for Smoking (BATS), which integrates behavioral activation principles with standard treatment guidelines to assist individuals in achieving short- and long-term smoking cessation. Through a series of sequential steps, BATS guides individuals who wish to quit smoking to increase their engagement in healthy, pleasurable, and value-consistent activities.

Design/methodology/approach

The document provides the BATS rationale and contains an abridged manual for use by clinicians and/or researchers in the context of clinical trials. Findings: BATS is accruing empirical evidence that suggests its ability to promote successful smoking cessation outcomes while decreasing any associated depressive symptoms.

Findings

BATS is accruing empirical evidence that suggests its ability to promote successful smoking cessation outcomes while decreasing any associated depressive symptoms.

Practical implications

A description of key components, forms, and strategies to address common treatment barriers are included.

Originality/value

BATS’s strong roots in learning theories and its idiographic nature allow for the intervention to be implemented flexibly across a wide range of settings and smoking populations. The treatment may also be combined seamlessly with pharmacotherapies. BATS targets both cigarette smoking and depressive symptoms, which constitute a significant barrier to cessation, through a common pathway: increasing rewarding activities. The treatment offers a parsimonious complement to standard smoking cessation treatments.

Cocaine-dependent adults and recreational cocaine users are more likely than controls to choose immediate unsafe sex over delayed safer sex

Cocaine users have a higher incidence of risky sexual behavior and HIV infection than nonusers. Our aim was to measure whether safer sex discount rates-a measure of the likelihood of having immediate unprotected sex versus waiting to have safer sex-differed between controls and cocaine users of varying severity. Of the 162 individuals included in the primary data analyses, 69 met the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR) criteria for cocaine dependence, 29 were recreational cocaine users who did not meet the dependence criteria, and 64 were controls. Participants completed the Sexual Discounting Task, which measures a person's likelihood of using a condom when one is immediately available and how that likelihood decreases as a function of delay to condom availability with regard to 4 images chosen by the participants of hypothetical sexual partners differing in perceived desirability and likelihood of having a sexually transmitted infection. When a condom was immediately available, the stated likelihood of condom use sometimes differed between cocaine users and controls, which depended on the image condition. Even after controlling for rates of condom use when one is immediately available, the cocaine-dependent and recreational users groups were more sensitive to delay to condom availability than controls. Safer sex discount rates were also related to intelligence scores. The Sexual Discounting Task identifies delay as a key variable that impacts the likelihood of using a condom among these groups and suggests that HIV prevention efforts may be differentially effective based on an individual's safer sex discount rate. (PsycINFO Database Record

Steep discounting of delayed monetary and food rewards in obesity: a meta-analysis

BACKGROUND

An increasing number of studies have investigated delay discounting (DD) in relation to obesity, but with mixed findings. This meta-analysis synthesized the literature on the relationship between monetary and food DD and obesity, with three objectives: (1) to characterize the relationship between DD and obesity in both case-control comparisons and continuous designs; (2) to examine potential moderators, including case-control v. continuous design, money v. food rewards, sample sex distribution, and sample age (18 years); and (3) to evaluate publication bias.

METHOD

From 134 candidate articles, 39 independent investigations yielded 29 case-control and 30 continuous comparisons (total n = 10 278). Random-effects meta-analysis was conducted using Cohen's d as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger tests, meta-regression of publication year and effect size, and imputation of missing studies.

RESULTS

The primary analysis revealed a medium effect size across studies that was highly statistically significant (d = 0.43, p < 10-14). None of the moderators examined yielded statistically significant differences, although notably larger effect sizes were found for studies with case-control designs, food rewards and child/adolescent samples. Limited evidence of publication bias was present, although the Begg-Mazumdar test and meta-regression suggested a slightly diminishing effect size over time.

CONCLUSIONS

Steep DD of food and money appears to be a robust feature of obesity that is relatively consistent across the DD assessment methodologies and study designs examined. These findings are discussed in the context of research on DD in drug addiction, the neural bases of DD in obesity, and potential clinical applications.

Toward quantifying the abuse liability of ultraviolet tanning: A behavioral economic approach to tanning addiction

Many adults engage in ultraviolet indoor tanning despite evidence of its association with skin cancer. The constellation of behaviors associated with ultraviolet indoor tanning is analogous to that in other behavioral addictions. Despite a growing literature on ultraviolet indoor tanning as an addiction, there remains no consensus on how to identify ultraviolet indoor tanning addictive tendencies. The purpose of the present study was to translate a behavioral economic task more commonly used in substance abuse to quantify the "abuse liability" of ultraviolet indoor tanning, establish construct validity, and determine convergent validity with the most commonly used diagnostic tools for ultraviolet indoor tanning addiction (i.e., mCAGE and mDSM-IV-TR). We conducted a between-groups study using a novel hypothetical Tanning Purchase Task to quantify intensity and elasticity of ultraviolet indoor tanning demand and permit statistical comparisons with the mCAGE and mDSM-IV-TR. Results suggest that behavioral economic demand is related to ultraviolet indoor tanning addiction status and adequately discriminates between potential addicted individuals from nonaddicted individuals. Moreover, we provide evidence that the Tanning Purchase Task renders behavioral economic indicators that are relevant to public health research. The present findings are limited to two ultraviolet indoor tanning addiction tools and a relatively small sample of high-risk ultraviolet indoor tanning users; however, these pilot data demonstrate the potential for behavioral economic assessment tools as diagnostic and research aids in ultraviolet indoor tanning addiction studies.

Novel Therapeutics for Addiction: Behavioral and Neuroeconomic Approaches

The maturing fields of behavioral- and neuro-economics provides conceptual understanding of the Competing Neurobehavioral Decision Systems theory (CNDS) and reinforcer pathology (i.e. high valuation of and excessive preference for drug reinforcers) allowing us to coherently categorize treatments into a theoretically comprehensive framework of addiction. In this chapter, we identify and clarify how existing and novel interventions can ameliorate reinforcer pathology in light of the CNDS and be leveraged to treat addiction.

The utility of behavioral economics in expanding the free-feed model of obesity

Animal models of obesity are numerous and diverse in terms of identifying specific neural and peripheral mechanisms related to obesity; however, they are limited when it comes to behavior. The standard behavioral measure of food intake in most animal models occurs in a free-feeding environment. While easy and cost-effective for the researcher, the free-feeding environment omits some of the most important features of obesity-related food consumption-namely, properties of food availability, such as effort and delay to obtaining food. Behavior economics expands behavioral measures of obesity animal models by identifying such behavioral mechanisms. First, economic demand analysis allows researchers to understand the role of effort in food procurement, and how physiological and neural mechanisms are related. Second, studies on delay discounting contribute to a growing literature that shows that sensitivity to delayed food- and food-related outcomes is likely a fundamental process of obesity. Together, these data expand the animal model in a manner that better characterizes how environmental factors influence food consumption.

Intense, Passionate, Romantic Love: A Natural Addiction? How the Fields That Investigate Romance and Substance Abuse Can Inform Each Other

Individuals in the early stage of intense romantic love show many symptoms of substance and non-substance or behavioral addictions, including euphoria, craving, tolerance, emotional and physical dependence, withdrawal and relapse. We have proposed that romantic love is a natural (and often positive) addiction that evolved from mammalian antecedents by 4 million years ago as a survival mechanism to encourage hominin pair-bonding and reproduction, seen cross-culturally today in Homo sapiens. Brain scanning studies using functional magnetic resonance imaging support this view: feelings of intense romantic love engage regions of the brain’s “reward system,” specifically dopamine-rich regions, including the ventral tegmental area, also activated during drug and/or behavioral addiction. Thus, because the experience of romantic love shares reward pathways with a range of substance and behavioral addictions, it may influence the drug and/or behavioral addiction response. Indeed, a study of overnight abstinent smokers has shown that feelings of intense romantic love attenuate brain activity associated with cigarette cue-reactivity. Could socially rewarding experiences be therapeutic for drug and/or behavioral addictions? We suggest that “self expanding” experiences like romance and expanding one’s knowledge, experience and self-perception, may also affect drug and/or behavioral addiction behaviors. Further, because feelings of romantic love can progress into feelings of calm attachment, and because attachment engages more plastic forebrain regions, there is a rationale for therapies that may help substance and/or behavioral addiction by promoting activation of these forebrain systems through long-term, calm, positive attachments to others, including group therapies. Addiction is considered a negative (harmful) disorder that appears in a population subset; while romantic love is often a positive (as well as negative) state experienced by almost all humans. Thus, researchers have not categorized romantic love as a chemical or behavioral addiction. But by embracing data on romantic love, it’s classification as an evolved, natural, often positive but also powerfully negative addiction, and its neural similarity to many substance and non-substance addictive states, clinicians may develop more effective therapeutic approaches to alleviate a range of the addictions, including heartbreak–an almost universal human experience that can trigger stalking, clinical depression, suicide, homicide, and other crimes of passion.

How Much Is Too Much to Pay for Internet Access? A Behavioral Economic Analysis of Internet Use

The popularity of online recreational activities, such as social networking, has dramatically increased the amount of time spent on the Internet. Excessive or inappropriate use of the Internet can result in serious adverse consequences. The current study used a behavioral economic task to determine if the amount of time spent online by problematic and nonproblematic users can be modified by price. The Internet Purchase Task was used to determine how much time undergraduate students (N=233) would spend online at 13 different prices. Despite high demand for Internet access when access was free, time spent online by both problematic and nonproblematic users decreased dramatically, even at low prices. These results suggest that the amount of time spent online may be modified by having a tangible cost associated with use, whereas having free access to the Internet may encourage excessive, problematic use.

Exercise training - A beneficial intervention in the treatment of alcohol use disorders?

BACKGROUND

A growing body of evidence suggests that exercise training may have multiple beneficial effects in individuals with mental health or substance use disorders. Yet, relatively little knowledge exists regarding the benefits of exercise training to augment treatment for alcohol use disorders (AUDs).

PURPOSE

The purpose of this narrative review is to present a summary of the growing body of published literature supporting exercise training as a treatment strategy for individuals with AUDs. We will provide evidence on the myriad of ways in which exercise may exert a positive effect on AUD outcomes including stress, anxiety, impulsivity, and depression. Further, we will explore how these mechanisms share common neurobiological pathways. The role of exercise in enhancing the social environment and increasing individual self-efficacy to reduce excess and/or inappropriate alcohol consumption will also be discussed.

DISCUSSION

We will conclude with a description of completed investigations involving exercise training and provide suggestions for next steps in this innovative field of study.

A modified exponential behavioral economic demand model to better describe consumption data

Behavioral economic demand analyses that quantify the relationship between the consumption of a commodity and its price have proven useful in studying the reinforcing efficacy of many commodities, including drugs of abuse. An exponential equation proposed by Hursh and Silberberg (2008) has proven useful in quantifying the dissociable components of demand intensity and demand elasticity, but is limited as an analysis technique by the inability to correctly analyze consumption values of zero. We examined an exponentiated version of this equation that retains all the beneficial features of the original Hursh and Silberberg equation, but can accommodate consumption values of zero and improves its fit to the data. In Experiment 1, we compared the modified equation with the unmodified equation under different treatments of zero values in cigarette consumption data collected online from 272 participants. We found that the unmodified equation produces different results depending on how zeros are treated, while the exponentiated version incorporates zeros into the analysis, accounts for more variance, and is better able to estimate actual unconstrained consumption as reported by participants. In Experiment 2, we simulated 1,000 datasets with demand parameters known a priori and compared the equation fits. Results indicated that the exponentiated equation was better able to replicate the true values from which the test data were simulated. We conclude that an exponentiated version of the Hursh and Silberberg equation provides better fits to the data, is able to fit all consumption values including zero, and more accurately produces true parameter values.

Male, But Not Female, Alcohol-Dependent African Americans Discount Delayed Gains More Steeply than Propensity-Score Matched Controls

RATIONALE

Alcohol dependence is known to be associated with steep discounting of delayed rewards, but its relation to the discounting of delayed losses and probabilistic rewards is unclear. Moreover, patterns of alcohol consumption vary considerably between communities, but previous research has not examined the relation between discounting and alcohol dependence in low-income African Americans.

OBJECTIVES

The goal of the present study was to determine whether low-income, alcohol-dependent African Americans differ from controls in the degree to which they discount delayed rewards, delayed losses, or probabilistic rewards.

METHODS

African-American participants, both cases and controls, were recruited from the same low-income neighborhoods, and propensity-score matching was used to further control for demographic differences. Participants performed three tasks that assessed their discounting of hypothetical monetary outcomes: delayed rewards, delayed losses, and probabilistic rewards.

RESULTS

Alcohol-dependent cases discounted delayed gains, but not delayed losses or probabilistic gains, more steeply than their matched controls. The difference in discounting of delayed gains was localized to the male cases, whose discounting was steeper than either the male controls or the female cases; no gender difference was observed between male and female controls.

CONCLUSIONS

The present results extend findings regarding discounting by substance abusers to a previously unstudied group, low-income African Americans, and suggest that in this group at least, alcohol dependence, particularly in males, may be more a reflection of choosing immediate rewards than of ignoring their delayed negative consequences.

Delay discounting for sucrose in alcohol-preferring and nonpreferring rats using a sipper tube within-sessions task

BACKGROUND

Delay discounting (DD) is a measure of impulsivity that quantifies preference for a small reward delivered immediately over a large reward delivered after a delay. It has been hypothesized that impulsivity is an endophenotype associated with increased risk for development of alcohol use disorders (AUDs); however, a causal role of impulsivity is difficult to determine with human studies. We tested this hypothesis by assessing the degree of DD present in alcohol-naïve rats selectively bred for either high- or low-alcohol preference.

METHODS

A novel adaptation of a within-sessions DD procedure was used to compare impulsivity differences between male alcohol-preferring (P) and nonpreferring (NP) rat lines (n = 6 per line) using a 5% sucrose reward. Animals chose between 2 options: 2-second sipper tube access delivered immediately (small reward) or 8-second access after a variable delay (large reward). Each 50-minute session consisted of 5 blocks of ten 60-second trials. Within each session, the delay to the large reward increased in each block of trials. Delays were gradually increased over 3 sets to attain a final delay set of 3, 8, 15, 18, and 25 seconds.

RESULTS

Prior to starting delays, there were no significant differences between lines in sucrose consumption or percent choice for the large reward, and both lines exhibited a clear preference for the large reward. After delays were initiated, choice for the large reward decreased as the delay to its presentation increased. Although discounting of the large, delayed reward was observed for both lines, the degree of discounting, or "impulsivity," was greater for P rats compared with NP rats.

CONCLUSIONS

P rats are more impulsive for sucrose rewards before exposure to alcohol compared with NP rats. Thus, individuals genetically predisposed toward developing AUDs may be more likely to engage in impulsive decision making prior to alcohol exposure.

An fMRI-Based Neural Signature of Decisions to Smoke Cannabis

Drug dependence may be at its core a pathology of choice, defined by continued decisions to use drugs irrespective of negative consequences. Despite evidence of dysregulated decision making in addiction, little is known about the neural processes underlying the most clinically relevant decisions drug users make: decisions to use drugs. Here, we combined functional magnetic resonance imaging (fMRI), machine learning, and human laboratory drug administration to investigate neural activation underlying decisions to smoke cannabis. Nontreatment-seeking daily cannabis smokers completed an fMRI choice task, making repeated decisions to purchase or decline 1-12 placebo or active cannabis 'puffs' ($0.25-$5/puff). One randomly selected decision was implemented. If the selected choice had been bought, the cost was deducted from study earnings and the purchased cannabis smoked in the laboratory; alternatively, the participant remained in the laboratory without cannabis. Machine learning with leave-one-subject-out cross-validation identified distributed neural activation patterns discriminating decisions to buy cannabis from declined offers. A total of 21 participants were included in behavioral analyses; 17 purchased cannabis and were thus included in fMRI analyses. Purchasing varied lawfully with dose and cost. The classifier discriminated with 100% accuracy between fMRI activation patterns for purchased vs declined cannabis at the level of the individual. Dorsal striatum, insula, posterior parietal regions, anterior and posterior cingulate, and dorsolateral prefrontal cortex all contributed reliably to this neural signature of decisions to smoke cannabis. These findings provide the basis for a brain-based characterization of drug-related decision making in drug abuse, including effects of psychological and pharmacological interventions on these processes.

Predictive Validity of a Cigarette Purchase Task in a Randomized Controlled Trial of Contingent Vouchers for Smoking in Individuals With Substance Use Disorders

INTRODUCTION

A cigarette purchase task (CPT) is a behavioral economic measure of the reinforcing value of smoking in monetary terms (ie, cigarette demand). This study investigated whether cigarette demand predicted response to contingent monetary rewards for abstinence among individuals with substance use disorders. It also sought to replicate evidence for greater price sensitivity at whole-dollar pack price transitions (ie, left-digit effects).

METHODS

Participants (N = 338) were individuals in residential substance use disorder treatment who participated in a randomized controlled trial that compared contingent vouchers to noncontingent vouchers for smoking abstinence. Baseline demand indices were used to predict number of abstinent days during the 14-day voucher period (after the reduction lead-in) and at 1 and 3 months afterward.

RESULTS

Demand indices correlated with measures of smoking and nicotine dependence. As measured by elasticity, intensity and O max, higher demand significantly predicted fewer abstinent exhaled carbon monoxide readings during voucher period for individuals in the noncontingent vouchers condition. Breakpoint exhibited a trend-level association with abstinent exhaled carbon monoxide readings. Demand indices did not predict abstinence in the contingent vouchers group, and did not predict abstinence at 1- and 3-month follow-ups. Left-digit price transitions were associated with significantly greater reductions in consumption.

CONCLUSIONS

The association of cigarette demand with smoking behavior only in the group for whom abstinence was not incentivized indicates that CPT assesses the value of smoking more than the value of money per se and that vouchers counteract the effects of the intrinsic reinforcing value of cigarettes. Results provide initial short-term evidence of predictive validity for the CPT indices.

IMPLICATIONS

This study provides the first evidence of the validity of the CPT for predicting early response to brief advice for smoking cessation plus nicotine replacement in smokers with substance dependence. However, demand for cigarettes did not predict voucher-based treatment response, indicating that incentives serve as a powerful motivator not to smoke that acts in opposition to the intrinsic reinforcing value of cigarettes and that the indices reflect the value of smoking more than the value of money per se.

The Experimental Tobacco Marketplace I: Substitutability as a Function of the Price of Conventional Cigarettes

INTRODUCTION

Behavioral economic studies of nicotine product consumption have traditionally examined substitution between two products and rarely examined substitution with more products. Increasing numbers of tobacco products available for commercial sale leads to more possible cross-product interactions, indicating a need to examine substitution in more complex arrangements that closely mirror the tobacco marketplace.

METHODS

The experimental tobacco marketplace (ETM) is an experimental online store that displays pictures, information, and prices for several tobacco products. Smokers were endowed with an account balance based on their weekly tobacco purchases. Participants then made potentially real purchases for seven (Experiment 1) or six (Experiment 2) tobacco/nicotine products under four price conditions for conventional cigarettes while prices for other products remained constant. Smokers returned 1 week later to report tobacco/nicotine use and return unused products for a refund.

RESULTS

In Experiment 1 (n = 22), cigarette purchasing decreased as a function of price. Substitution was greatest for electronic cigarettes and cigarillos and significant for electronic cigarettes. Experiment 2 (n = 34) was a replication of Experiment 1, but with cigarillos unavailable in the ETM. In Experiment 2, cigarette purchases decreased as a function of price. Substitution was robust and significant for electronic cigarettes and Camel Snus.

CONCLUSIONS

The ETM is a novel, practical assay that mimics the real-world marketplace, and functions as a simple research tool for both researchers and participants. Across the two experiments the product mix in the ETM altered which products functioned as substitutes suggesting complex interactions between purchasing and product availability.

IMPLICATIONS

This article adds a novel method of collecting purchasing data that mimics real world purchasing to the existing literature. The ETM is a practical avenue by which to study both hypothetical and potentially real purchasing.

A randomized controlled trial of a behavioral economic intervention for alcohol and marijuana use

A recent study demonstrated that a single 50-min supplemental session that targeted the behavioral economic mechanisms of substance-free reinforcement and delayed reward discounting (Substance-Free Activity Session: SFAS) enhanced the efficacy of a standard alcohol brief motivational intervention (BMI) for college drinkers. The purpose of the current study was to conduct a randomized controlled trial intended to replicate and extend the aforementioned study by focusing on both drug and alcohol misuse and reducing session length in order to enhance dissemination potential. Participants were 97 college students (58.8% women; 59.8% White/Caucasian, and 30.9% African American; M age = 20.01, SD = 2.23) who reported at least 1 heavy drinking episode in the past month (M = 4.01 episodes). Most participants (62%) reported recent marijuana use (M = 12.22 days of past-month use). After completing a baseline assessment and an individual 30-min alcohol-focused BMI, participants were randomized to either the 30-min SFAS session or an education control session. A series of mixed model intent-to-treat analyses revealed that both groups reported drinking reductions and that participants in the BMI + SFAS group reported fewer days using marijuana at the 6-month follow-up. These results do not support the incremental efficacy of the briefer SFAS for reducing drinking but suggest that it may improve marijuana outcomes. Future research is needed to identify the ideal length and timing of the SFAS supplement to BMIs.

Alcohol craving and demand mediate the relation between posttraumatic stress symptoms and alcohol-related consequences

Posttraumatic stress (PTS) symptoms are associated with alcohol-related consequences, but there is a need to understand mediators that may help explain the reasons for this relationship. Individuals with PTS may experience elevated craving and alcohol reward value (demand), which may contribute to risk for alcohol-related consequences. We examined relationships between PTS status, craving, alcohol demand, and alcohol-related consequences in PTS-positive (n = 64) and PTS-negative (n = 200) college students (M age = 21.7; 77% women; 54% Caucasian; 34% African American) who endorsed past-month alcohol use. We tested craving and alcohol demand as mediators of the relation between PTS status and alcohol-related consequences. Craving (B = .04, SE = .02, 95% CI [.01, .10]), demand intensity (B = .02, SE = .02, 95% CI [.001, .07]), and demand elasticity (B = .05, SE = .03, 95% CI [.006, .12]) significantly mediated the association between PTS symptoms and alcohol-related consequences. Craving remained a significant mediator in a multiple mediators model (B = .08, SE = .04, 95% CI [.03, .19]). Craving and alcohol demand may partially explain the relation between PTS status and alcohol-related consequences. Craving may be especially salient for individuals with PTS symptoms, as it may lead to more severe alcohol-related consequences even in the absence of elevated alcohol consumption.

Texting while driving as impulsive choice: A behavioral economic analysis

The goal of the present study was to examine the utility of a behavioral economic analysis to investigate the role of delay discounting in texting while driving. A sample of 147 college students completed a survey to assess how frequently they send and read text messages while driving. Based on this information, students were assigned to one of two groups: 19 students who frequently text while driving and 19 matched-control students who infrequently text while driving but were similar in gender, age, years of education, and years driving. The groups were compared on the extent to which they discounted, or devalued, delayed hypothetical monetary rewards using a delay-discounting task. In this task, students made repeated choices between $1000 available after a delay (ranging from 1 week to 10 years) and an equal or lesser amount of money available immediately. The results show that the students who frequently text while driving discounted delayed rewards at a greater rate than the matched control students. The study supports the conclusions that texting while driving is fundamentally an impulsive choice made by drivers, and that a behavioral economic approach may be a useful research tool for investigating the decision-making processes underlying risky behaviors.

Examining Delay Discounting of Condom-Protected Sex Among Men Who Have Sex with Men Using Crowdsourcing Technology

Some men who have sex with men (MSM) have unprotected anal intercourse (UAI) in situations that put them at risk for HIV infection despite having the knowledge and skills to avoid these risks. The present study examined the potential role of delay discounting in sexual HIV risk behavior among MSM. Participants (n = 108) completed the Sexual Discounting Task and a questionnaire regarding UAI and other variables associated with HIV risk (e.g., age, socioeconomic status, substance use, psychiatric problems). MSM discounted the value of condom-protected anal intercourse in a manner that was orderly, hyperbolic, and sensitive to partner characteristics that likely influence realworld decisions about using condoms. Steeper discounting was associated with UAI, and other factors related to sexual HIV risk among MSM, including young age, socioeconomic disadvantage, substance use, sex under the influence of substances, and depression). Delay discounting is likely a critical, but underappreciated facet of HIV risk among MSM.

Negative mood reverses devaluation of goal-directed drug-seeking favouring an incentive learning account of drug dependence

BACKGROUND

Two theories explain how negative mood primes smoking behaviour. The stimulus-response (S-R) account argues that in the negative mood state, smoking is experienced as more reinforcing, establishing a direct (automatic) association between the negative mood state and smoking behaviour. By contrast, the incentive learning account argues that in the negative mood state smoking is expected to be more reinforcing, which integrates with instrumental knowledge of the response required to produce that outcome.

OBJECTIVES

One differential prediction is that whereas the incentive learning account anticipates that negative mood induction could augment a novel tobacco-seeking response in an extinction test, the S-R account could not explain this effect because the extinction test prevents S-R learning by omitting experience of the reinforcer.

METHODS

To test this, overnight-deprived daily smokers (n = 44) acquired two instrumental responses for tobacco and chocolate points, respectively, before smoking to satiety. Half then received negative mood induction to raise the expected value of tobacco, opposing satiety, whilst the remainder received positive mood induction. Finally, a choice between tobacco and chocolate was measured in extinction to test whether negative mood could augment tobacco choice, opposing satiety, in the absence of direct experience of tobacco reinforcement.

RESULTS

Negative mood induction not only abolished the devaluation of tobacco choice, but participants with a significant increase in negative mood increased their tobacco choice in extinction, despite satiety.

CONCLUSIONS

These findings suggest that negative mood augments drug-seeking by raising the expected value of the drug through incentive learning, rather than through automatic S-R control.

Behavioral economic predictors of brief alcohol intervention outcomes

OBJECTIVE

The present study attempted to determine whether behavioral economic indices of elevated alcohol reward value, measured before and immediately after a brief alcohol intervention, predict treatment response.

METHOD

Participants were 133 heavy drinking college students (49.6% female, 51.4% male; 64.3% Caucasian, 29.5% African American) who were randomized to 1 of 3 conditions: motivational interviewing plus personalized feedback (brief motivational interventions; BMI), computerized personalized feedback intervention (electronic check-up to go; e-CHUG), and assessment only.

RESULTS

Baseline level of alcohol demand intensity (maximum consumption) significantly predicted drinks per week and alcohol problems at 1-month follow-up and baseline relative discretionary expenditures on alcohol significantly predicted drinks per week and alcohol problems at 6-month follow-up. BMI and e-CHUG were associated with an immediate postsession reduction in alcohol demand (p < .001, ηp2 = .29) that persisted at the 1-month follow-up, with greater postsession reductions in the BMI condition (p = .02, ηp2 = .06). Reductions in demand intensity and Omax (maximum expenditure) immediately postintervention significantly predicted drinking reductions at 1-month follow up (p = .04, ΔR2 = .02, and p = .01, ΔR2 = .03, respectively). Reductions in relative discretionary expenditures on alcohol at 1-month significantly predicted drinking (p = .002, ΔR2 = .06,) and alcohol problem (p < .001, ΔR2 = .13) reductions at the 6-month follow-up.

CONCLUSIONS

These results suggest that behavioral economic reward value indices may function as risk factors for poor intervention response and as clinically relevant markers of change in heavy drinkers.

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.

Area under the curve as a novel metric of behavioral economic demand for alcohol

Behavioral economic purchase tasks can be readily used to assess demand for a number of addictive substances, including alcohol, tobacco, and illicit drugs. However, several methodological limitations associated with the techniques used to quantify demand may reduce the utility of demand measures. In the present study, we sought to introduce area under the curve (AUC), commonly used to quantify degree of delay discounting, as a novel index of demand. A sample of 207 heavy-drinking college students completed a standard alcohol purchase task and provided information about typical weekly drinking patterns and alcohol-related problems. Level of alcohol demand was quantified using AUC--which reflects the entire amount of consumption across all drink prices--as well as the standard demand indices (e.g., intensity, breakpoint, Omax, Pmax, and elasticity). Results indicated that AUC was significantly correlated with each of the other demand indices (rs = .42-.92), with particularly strong associations with Omax (r = .92). In regression models, AUC and intensity were significant predictors of weekly drinking quantity, and AUC uniquely predicted alcohol-related problems, even after controlling for drinking level. In a parallel set of analyses, Omax also predicted drinking quantity and alcohol problems, although Omax was not a unique predictor of the latter. These results offer initial support for using AUC as an index of alcohol demand. Additional research is necessary to further validate this approach and to examine its utility in quantifying demand for other addictive substances such as tobacco and illicit drugs.

Predictors of delay discounting among smokers: education level and a Utility Measure of Cigarette Reinforcement Efficacy are better predictors than demographics, smoking characteristics, executive functioning, impulsivity, or time perception

Ninety-four smokers completed the delay discounting procedure for either hypothetical amounts of money, $10 (money) and $1000 (money) or hypothetical amounts of cigarettes ($10 and $1000 worth of cigarettes). We investigated how variables previously found to be related to rates of delay discounting accounted for the observed results. These variables included the following: demographic information, smoking characteristics, executive function abilities, impulsivity, time perception, and the Utility Measure of Cigarette Reinforcing Efficacy (UMCE). Education level and UMCE were each significantly correlated with 3 out of 4 of the discounting measures. Moreover, the largest effect sizes observed were between these two measures and the four discounting measures. All potential discounting predictors were also investigated using step-wise linear regression with Bayesian Information Criterion (BIC) analysis—these BIC models revealed that education level and UMCE accounted for large portions of the variance. We conclude that education level and UMCE were the most consistent predictors of discounting. This data is discussed within the framework of a widely accepted neuroeconomic model that suggests that two brain systems separately assess two separate facets of decision-making, and the interplay between these two systems determines self-control in smokers. We hypothesize that education level and UMCE may serve as surrogate measures of the functionality of these two systems and that discounting may be a sentinel measure of self-control.

Cigarette Smoking During Substance Use Disorder Treatment: Secondary Outcomes from a National Drug Abuse Treatment Clinical Trials Network study

INTRODUCTION

The majority of patients enrolled in treatment for substance use disorders (SUDs) also use tobacco. Many will continue to use tobacco even during abstinence from other drugs and alcohol, often leading to smoking-related illnesses. Despite this, little research has been conducted to assess the influence of being a smoker on SUD treatment outcomes and changes in smoking during a treatment episode.

METHODS

In this secondary analysis, cigarette smoking was evaluated in participants completing outpatient SUD treatment as part of a multi-site study conducted by the National Drug Abuse Treatment Clinical Trials Network. Analyses included the assessment of changes in smoking and nicotine dependence via the Fagerström Test for Nicotine Dependence during the 12-week study among all smokers (aim #1), specifically among those in the experimental treatment group (aim #2), and the moderating effect of being a smoker on treatment outcomes (aim #3).

RESULTS

Participants generally did not reduce or quit smoking throughout the course of the study. Among a sub-set of participants with higher baseline nicotine dependence scores randomized to the control arm, scores at the end of treatment were lower compared to the experimental arm, though measures of smoking quantity did not appear to decrease. Further, being a smoker was associated with poorer treatment outcomes compared to non-smokers enrolled in the trial.

CONCLUSIONS

This study provides evidence that patients enrolled in community-based SUD treatment continue to smoke, even when abstaining from drugs and alcohol. These results add to the growing literature encouraging the implementation of targeted, evidence-based interventions to promote abstinence from tobacco among SUD treatment patients.

Delay and probability discounting of sexual and monetary outcomes in individuals with cocaine use disorders and matched controls

Individuals with cocaine use disorders are disproportionately affected by HIV/AIDS, partly due to higher rates of unprotected sex. Recent research suggests delay discounting of condom use is a factor in sexual HIV risk. Delay discounting is a behavioral economic concept describing how delaying an event reduces that event’s value or impact on behavior. Probability discounting is a related concept describing how the uncertainty of an event decreases its impact on behavior. Individuals with cocaine use disorders (n = 23) and matched non-cocaine-using controls (n = 24) were compared in decision-making tasks involving hypothetical outcomes: delay discounting of condom-protected sex (Sexual Delay Discounting Task), delay discounting of money, the effect of sexually transmitted infection (STI) risk on likelihood of condom use (Sexual Probability Discounting Task), and probability discounting of money. The Cocaine group discounted delayed condom-protected sex (i.e., were more likely to have unprotected sex vs. wait for a condom) significantly more than controls in two of four Sexual Delay Discounting Task partner conditions. The Cocaine group also discounted delayed money (i.e., preferred smaller immediate amounts over larger delayed amounts) significantly more than controls. In the Sexual Probability Discounting Task, both groups showed sensitivity to STI risk, however the groups did not differ. The Cocaine group did not consistently discount probabilistic money more or less than controls. Steeper discounting of delayed, but not probabilistic, sexual outcomes may contribute to greater rates of sexual HIV risk among individuals with cocaine use disorders. Probability discounting of sexual outcomes may contribute to risk of unprotected sex in both groups. Correlations showed sexual and monetary results were unrelated, for both delay and probability discounting. The results highlight the importance of studying specific behavioral processes (e.g., delay and probability discounting) with respect to specific outcomes (e.g., monetary and sexual) to understand decision making in problematic behavior.

The behavioral economics of driving after drinking among college drinkers

BACKGROUND

Driving after drinking (DAD) among college students is a significant public health concern, yet little is known about specific theoretical risk factors for DAD, beyond drinking level, among college student drinkers. This study had the following aims: (i) to examine the associations between elevated alcohol demand and DAD, (ii) to determine whether demand decreases in response to a hypothetical driving scenario, (iii) to determine whether drivers who report DAD in the past 3 months would show less of a reduction in demand in response to the hypothetical driving scenario, and (iv) to determine whether delayed reward discounting (DRD) is associated with DAD.

METHOD

Participants were 419 college students who reported at least 1 day of past-month alcohol use. Participants completed 2 alcohol purchase tasks (APTs) that assessed hypothetical alcohol consumption across 17 drink prices with and without a driving scenario, a delay-discounting task, and a series of questions regarding DAD.

RESULTS

In logistic regression models that controlled for drinking level, demographics, and sensation seeking, participants reporting higher demand intensity (95% confidence interval [95% CI] [1.04, 2.34]), breakpoint (95% CI [1.23, 2.28]), Omax (95% CI [1.03, 1.53]), and lower elasticity (95% CI [0.15, 1.02]) were more likely to report DAD. Additionally, in analyses of covariance, DAD(+) participants exhibited significantly less of a reduction in demand between the standard and the driving APT (intensity, p < 0.01, breakpoint, p = 0.05, and Omax , p < 0.01). A binary logistic regression model with identical covariates revealed that DRD is not associated with DAD.

CONCLUSIONS

DAD is associated with elevated/inelastic demand and less sensitivity to a hypothetical driving scenario. Drinkers with elevated demand should be prioritized for DAD intervention efforts.

Origins of food reinforcement in infants

BACKGROUND

Rapid weight gain in infancy is associated with a higher risk of obesity in children and adults. A high relative reinforcing value of food is cross-sectionally related to obesity; lean children find nonfood alternatives more reinforcing than do overweight/obese children. However, to our knowledge, there is no research on how and when food reinforcement develops.

OBJECTIVE

This study was designed to assess whether the reinforcing value of food and nonfood alternatives could be tested in 9- to 18-mo-old infants and whether the reinforcing value of food and nonfood alternatives is differentially related to infant weight status.

DESIGN

Reinforcing values were assessed by using absolute progressive ratio schedules of reinforcement, with presentation of food and nonfood alternatives counterbalanced in 2 separate studies. Two nonfood reinforcers [Baby Einstein-Baby MacDonald shows (study 1, n = 27) or bubbles (study 2, n = 30)] were tested against the baby's favorite food. Food reinforcing ratio (FRR) was quantified by measuring the reinforcing value of food (Food Pmax) in proportion to the total reinforcing value of food and a nonfood alternative (DVD Pmax or BUB Pmax).

RESULTS

Greater weight-for-length z score was associated with a greater FRR of a favorite food in study 1 (FRR-DVD) (r = 0.60, P < 0.001) and FRR of a favorite food in study 2 (FRR-BUB) (r = 0.49, P = 0.006), primarily because of the strong association between greater weight-for-length z score and lower DVD Pmax (r = -0.71, P < 0.0001) and BUB Pmax (r = -0.53, P = 0.003). Infant monthly weight gain was positively associated with FRR-DVD (r = 0.57, P = 0.009) and FRR-BUB (r = 0.37, P = 0.047).

CONCLUSIONS

Our newly developed paradigm, which tested 2 different nonfood alternatives, demonstrated that lean infants find nonfood alternatives more reinforcing than do overweight/obese infants. This observation suggests that strengthening the alternative reinforcers may have a protective effect against childhood obesity.

Using behavioral economics to predict opioid use during prescription opioid dependence treatment

BACKGROUND

Research grounded in behavioral economics has previously linked addictive behavior to disrupted decision-making and reward-processing, but these principles have not been examined in prescription opioid addiction, which is currently a major public health problem. This study examined whether pre-treatment drug reinforcement value predicted opioid use during outpatient treatment of prescription opioid addiction.

METHODS

Secondary analyses examined participants with prescription opioid dependence who received 12 weeks of buprenorphine-naloxone and counseling in a multi-site clinical trial (N=353). Baseline measures assessed opioid source and indices of drug reinforcement value, including the total amount and proportion of income spent on drugs. Weekly urine drug screens measured opioid use.

RESULTS

Obtaining opioids from doctors was associated with lower pre-treatment drug spending, while obtaining opioids from dealers/patients was associated with greater spending. Controlling for demographics, opioid use history, and opioid source frequency, patients who spent a greater total amount (OR=1.30, p<.001) and a greater proportion of their income on drugs (OR=1.31, p<.001) were more likely to use opioids during treatment.

CONCLUSIONS

Individual differences in drug reinforcement value, as indicated by pre-treatment allocation of economic resources to drugs, reflects propensity for continued opioid use during treatment among individuals with prescription opioid addiction. Future studies should examine disrupted decision-making and reward-processing in prescription opioid users more directly and test whether reinforcer pathology can be remediated in this population.

Further evidence of close correspondence for alcohol demand decision making for hypothetical and incentivized rewards

Alcohol purchase tasks (APTs) are increasingly being used to assess behavioral economic demand for alcohol. Prior studies utilizing APTs have typically assessed demand for hypothetical outcomes, making the extent to which these hypothetical measures reflect preferences when actual rewards are at stake an important empirical question. This study examined alcohol demand across hypothetical and incentivized APTs. Nineteen male heavy drinkers completed two APTs - one for hypothetical alcohol and another in which one randomly-selected outcome was provided. Participants were given an opportunity to consume the alcohol associated with their choice on the incentivized APT during a self-administration period in a simulated bar environment. Results indicated generally close correspondence between APT versions, though participants were more sensitive to increases in price and tended to consume more at low prices on the incentivized version. Estimated consumption on the incentivized APT was highly correlated with the amount of alcohol consumed in the laboratory (r=.87, p<.001), suggesting that APT responses are valid indicators of actual drinking behavior. These results provide further evidence of congruence of demand-based decision-making when rewards are hypothetical vs. actually available. Implications for behavioral economic approaches to addictive behavior and directions for future research are discussed.

Increasing the Value of an Alternative Monetary Reinforcer Reduces Cigarette Choice in Adolescents

INTRODUCTION

Smoking can be conceptualized as an operant behavior maintained by the reinforcing effects of cigarettes. Changing the magnitude and availability of alternative reinforcers should shift behavior away from smoking. Adults' smoking behavior is sensitive to the magnitude and availability of alternative reinforcers; however, the extent to which the same is true for adolescents has not yet been shown in the laboratory.

METHODS

To test the sensitivity of adolescent smoking behavior to changes in the magnitude of alternative reinforcement, we gave adolescents who abstained overnight the opportunity to make 20 choices between receiving two puffs of their usual-brand cigarette or money. The magnitude of the monetary reinforcer was varied across sessions in counterbalanced order ($0.00, $0.10, and $0.50).

RESULTS

Results indicated that adolescents' choices for puffs decreased as a function of increasing monetary reinforcer magnitude, while money choices increased. This effect was moderated by baseline smoking level and by gender, such that heavier-smoking participants and males made more cigarette choices when the alternative monetary value was zero, and decreased their choices more steeply in response to increasing monetary value.

CONCLUSIONS

The current study validates a laboratory choice procedure for studying smoking in adolescents, and demonstrates that adolescent smoking behavior is sensitive to changes in the magnitude of concurrently available monetary reinforcers. The current paradigm can be adapted and applied to explore the effects of other variables that may affect cigarette choice in adolescents.

Ultra-violet indoor tanning addiction: a reinforcer pathology interpretation

Ultra-violet indoor tanning (UVIT) is a pervasive issue that is increasing at record rates, despite obvious and well-publicized links to skin cancer. Recent studies on UVIT have found that frequent users face difficulty quitting and report symptomatology similar to substance-related disorders, causing the medical field to begin classifying excessive UVIT use as an addicting behavior. Despite calls for research, relatively little behavioral research has been aimed at determining the psychology of UVIT. This mini-review reinterprets the existing dermatology literature in light of the reinforcer pathology model of addiction. The relevancy of this model, in conjunction with the similarities between UVIT addiction and other substance-related addiction, suggests that behavioral economic research on UVIT is overdue. This mini-review concludes with directions for future research in this area.

Using Behavior Economics to Understand Alcohol Use Disorders: A Concise Review and Identification of Research Priorities

We review recent advances in the application of behavioral economics to alcohol use disorders (AUDs). Specifically, we review individual differences in alcohol demand (i.e., the relative reinforcing value of alcohol) and delayed reward discounting (i.e., impulsive decision making) in relation to AUDs. Additionally, we review the efficacy of reinforcement-based clinical applications. What emerges from the literature is an extensive body of cross-sectional research implicating alcohol demand and delayed reward discounting with alcohol misuse. However, more research is needed to examine these domains across the lifespan in order to understand their longitudinal trajectories. Similarly, clinical research is consistently supportive of reinforcement-based clinical interventions, but the number of randomized controlled trials to date is relatively small and there has been limited examination of the putative mechanisms of behavior change.