Relations among delay discounting, addictions, and money mismanagement: implications and future directions

No effects of acute stress on monetary delay discounting: A systematic literature review and meta-analysis

Many everyday decisions, including those concerning our health, finances and the environment, involve choosing between a smaller but imminent reward (e.g., €20 now) and a later but larger reward (e.g., €40 in a month). The extent to which an individual prefers smaller imminent rewards over larger delayed rewards can be measured using delay discounting tasks. Acute stress induces a cascade of biological and psychological responses with potential consequences for how individuals think about the future, process rewards, and make decisions, all of which can impact delay discounting. Several studies have shown that individuals focus more on imminent rewards under stress. These findings have been used to explain why individuals make detrimental choices under acute stress. Yet, the evidence linking acute stress to delay discounting is equivocal. To address this uncertainty, we conducted a meta-analysis of 11 studies (14 effects) to systematically quantify the effects of acute stress on monetary delay discounting. Overall, we find no effect of acute stress on delay discounting, compared to control conditions (SMD = -0.18, 95% CI [-0.57, 0.20], p = 0.32). We also find that neither the gender/sex of the participants, the type of stressor (e.g., physical vs. psychosocial) nor whether monetary decisions were hypothetical or incentivized (i.e. monetary decisions were actually paid out) moderated the impact of acute stress on monetary delay discounting. We argue that establishing the effects of acute stress on the separate processes involved in delay discounting, such as reward valuation and prospection, will help to resolve the inconsistencies in the field.

Memory, fluid reasoning, and functional capacity in adults experiencing homelessness

BACKGROUND AND OBJECTIVE

In individuals experiencing homelessness, determinants of functional capacity (i.e. the ability to perform activities of daily living) are poorly understood. Identifying potentially modifiable correlates of functional capacity, such as cognitive abilities, may inform treatment targets to address independence and housing stability. This study aimed to identify the strongest neuropsychological predictors of variance in functional performance in 100 adults living in a homeless shelter.

METHODS

Participants completed a brief cognitive screening test, from which four composite scores were derived, as well as tests of processing speed, fluid reasoning, premorbid intellectual function, and performance-based functional capacity. We conducted a hierarchical linear regression to predict variance in functional capacity.

RESULTS

Beyond the impact of education and premorbid intellectual function, better memory and fluid reasoning predicted better functional performance.

CONCLUSIONS

Although our cross-sectional design does not permit causal inference, it is possible that interventions targeting memory and fluid reasoning may improve functional ability in individuals experiencing homelessness.

Use of experimental medicine approaches for the development of novel psychiatric treatments based on orexin receptor modulation

Despite progress in understanding the pathological mechanisms underlying psychiatric disorders, translation from animal models into clinical use remains a significant bottleneck. Preclinical studies have implicated the orexin neuropeptide system as a potential target for psychiatric disorders through its role in regulating emotional, cognitive, and behavioral processes. Clinical studies are investigating orexin modulation in addiction and mood disorders. Here we review performance-outcome measures (POMs) arising from experimental medicine research methods which may show promise as markers of efficacy of orexin receptor modulators in humans. POMs provide objective measures of brain function, complementing patient-reported or clinician-observed symptom evaluation, and aid the translation from preclinical to clinical research. Significant challenges include the development, validation, and operationalization of these measures. We suggest that collaborative networks comprising clinical practitioners, academics, individuals working in the pharmaceutical industry, drug regulators, patients, patient advocacy groups, and other relevant stakeholders may provide infrastructure to facilitate validation of experimental medicine approaches in translational research and in the implementation of these approaches in real-world clinical practice.

Cardiac sensitivity to rewards in cognitively inflexible nonclinical participants

Background

In psychopathologies characterized by compulsive decision-making, core impairments include cognitive inflexibility and excessive sensitivity to rewards. It has been posited that traits shared by nonclinical individuals and psychiatric patients could help explain the pathogenesis of compulsive decision-making.

Methods

To investigate whether cognitive inflexibility predisposes nonclinical individuals to poor choices and hyper-reactivity to reward, we recruited people with high and low scores for cognitive persistence and used the Iowa Gambling Task to assess decision-making and cardiac reactivity to monetary gains/losses.

Results

As is frequently observed in psychophysiological research, the data indicated discrepancies among self-reports, behavior, and physiology. Cognitive inflexibility was not related to worse performance; however, monetary gains, in line with the literature, prompted marked cardiac accelerations. Consistent with our research goal, only inflexible participants showed large cardiac accelerations during the largest monetary wins.

Discussion

Taken together, the data confirm an association between cognitive persistence and physiological reward sensitivity in a nonclinical population. The findings are in line with recent theories on the development of compulsive behaviors that consider cognitive inflexibility as a transdiagnostic impairment and predisposing factor for excessive reactivity to rewards, and might act both as a preexisting individual trait and drug-induced deficit.

Not When But Whether: Modality and Future Time Reference in English and Dutch

Previous research on linguistic relativity and economic decisions hypothesized that speakers of languages with obligatory tense marking of future time reference (FTR) should value future rewards less than speakers of languages which permit present tense FTR. This was hypothesized on the basis of obligatory linguistic marking (e.g., will) causing speakers to construe future events as more temporally distal and thereby to exhibit increased "temporal discounting": the subjective devaluation of outcomes as the delay until they will occur increases. However, several aspects of this hypothesis are incomplete. First, it overlooks the role of "modal" FTR structures which encode notions about the likelihood of future outcomes (e.g., might). This may influence "probability discounting": the subjective devaluation of outcomes as the probability of their occurrence decreases. Second, the extent to which linguistic structures are subjectively related to temporal or probability discounting differences is currently unknown. To address these, we elicited FTR language and subjective ratings of temporal distance and probability from speakers of English, which exhibits strongly grammaticized FTR, and Dutch, which does not. Several findings went against the predictions of the previous hypothesis: Framing an FTR statement in the present ("Ellie arrives later on") versus the future tense ("…will arrive…") did not affect ratings of temporal distance; English speakers rated future statements as relatively more temporally proximal than Dutch speakers; and English and Dutch speakers rated future tenses as encoding high certainty, which suggests that obligatory future tense marking might result in less discounting. Additionally, compared with Dutch speakers, English speakers used more low-certainty terms in general (e.g., may) and as a function of various experimental factors. We conclude that the prior cross-linguistic observations of the link between FTR and psychological discounting may be caused by the connection between low-certainty modal structures and probability discounting, rather than future tense and temporality.

Sex differences in associations between delay discounting and expectancies for alcohol analgesia

Self-medication of pain with alcohol is prevalent, and expectancies for alcohol analgesia likely influence pain relief and alcohol consumption. Hazardous alcohol use has been associated with greater delay discounting rates; however, little is known about the relationship between delay discounting and expectancies for alcohol analgesia. Therefore, the present study examined sex differences in associations between delay discounting and expectancies for alcohol analgesia. Healthy drinkers without chronic pain (N = 53) completed measures of expectancies for alcohol analgesia, alcohol use, and alcohol outcome expectancies. A five-trial adjusting-delay discounting task (DDT) for monetary outcomes was also administered. Regression analyses revealed that sex moderated the relationship between delay discounting and expectancies for alcohol analgesia. Steeper delay discounting rates were associated with weaker expectancies for alcohol analgesia among men when adjusting for average alcohol consumption. Among women, nonsignificant associations between delay discounting rates and expectancies for alcohol analgesia were observed. These findings provide initial evidence of sex differences in associations between delay discounting and expectancies for alcohol analgesia. The directionality of these associations was unexpected and may have implications for patterns of self-medication with alcohol. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Hyperbolic discounting rates and risk for problematic alcohol use in youth enrolled in the Adolescent Brain and Cognitive Development study

Adolescence is the peak period for the emergence of substance use, which can lead to long-term psychosocial, occupational and interpersonal complications. Ongoing large-scale, longitudinal, consortium initiatives, such as the Adolescent Brain and Cognitive Development (ABCD) study, offer unprecedented opportunities to elucidate key risk factors for problematic substance use in a well-powered sample and to examine how changes in risk factors relate to symptoms across time. Delay discounting has been proposed as a putative risk marker for early substance-use initiation and other forms of psychopathology. However, the extent to which other factors (e.g., socio-economic status and cognitive ability) influence discounting behaviour in young adolescents is not well established. The present study leverages data from the ABCD study (n = 11 045) to assess associations between core demographic and familial variables and delay discounting in youth-operationalized using hyperbolic discounting rates (k)-before the onset of significant psychopathology. Model estimates revealed significant effects of individual difference factors (e.g., sex and socio-economic status) and alcohol risk status (based on family history) on delay discounting. No significant differences were observed in the primary sample when comparing the presence of parent drug problems or prenatal drug exposures. These effects will require replication in later waves of ABCD. Nonetheless, these results provide support for delay discounting as a potential risk marker for problematic alcohol use and demonstrate a relationship between key demographic variables and adolescent discounting behaviour. Further, these results provide an empirical baseline from which developmental trajectories of delay discounting and substance use may be tracked throughout future waves of ABCD.

The phenotype of recovery II: The association between delay discounting, self-reported quality of life, and remission status among individuals in recovery from substance use disorders

Quality of life (QOL) and delay discounting (preference for smaller, immediate rewards) are significantly associated with substance use status, severity, and treatment outcomes. Associations between delay discounting and QOL among individuals in recovery from substance use have not been investigated. In this 2-study investigation, using data collected from The International Quit & Recovery Registry, we examined the association between QOL, discounting rates, and remission status among individuals in recovery from SUD. Study 1 (N = 166) investigated the relationship between delay discounting and QOL among individuals in recovery from SUD. Study 2 (N = 282) aimed to validate and extend the results of Study 1 by assessing the association between the remission status, delay discounting, and QOL among individuals in recovery from alcohol use disorder (AUD). In both studies, delay discounting was a significant predictor of QOL domains of physical health, psychological, and environment even after controlling for age, gender, race, ethnicity, education, and days since last use. In Study 2, a mediation analysis using Hayes's methods revealed that the association between the remission status and QOL domains of physical health, psychological and environment were partially mediated by the discounting rates. The current study expands the generality of delay discounting and indicates that discounting rates predict QOL and remission status among individuals in recovery from substance use disorders. This finding corroborates the recent characterizations of delay discounting as a candidate behavioral marker of addiction and may help identify subgroups that require special treatment or unique interventions to overcome their addiction. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Links between problem gambling and spending on booster packs in collectible card games: A conceptual replication of research on loot boxes

Loot boxes are digital containers of randomised rewards present in some video games which are often purchasable for real world money. Recently, concerns have been raised that loot boxes might approximate traditional gambling activities, and that people with gambling problems have been shown to spend more on loot boxes than peers without gambling problems. Some argue that the regulation of loot boxes as gambling-like mechanics is inappropriate because similar activities which also bear striking similarities to traditional forms of gambling, such as collectable card games, are not subject to such regulations. Players of collectible card games often buy sealed physical packs of cards, and these 'booster packs' share many formal similarities with loot boxes. However, not everything which appears similar to gambling requires regulation. Here, in a large sample of collectible card game players (n = 726), we show no statistically significant link between in real-world store spending on physical booster and problem gambling (p = 0.110, η2 = 0.004), and a trivial in magnitude relationship between spending on booster packs in online stores and problem gambling (p = 0.035, η2 = 0.008). Follow-up equivalence tests using the TOST procedure rejected the hypothesis that either of these effects was of practical importance (η2 > 0.04). Thus, although collectable card game booster packs, like loot boxes, share structural similarities with gambling, it appears that they may not be linked to problem gambling in the same way as loot boxes. We discuss potential reasons for these differences. Decisions regarding regulation of activities which share structural features with traditional forms of gambling should be made on the basis of definitional criteria as well as whether people with gambling problems purchase such items at a higher rate than peers with no gambling problems. Our research suggests that there is currently little evidence to support the regulation of collectable card games.

Financial Capability in Addiction Research and Clinical Practice

Background:Substance use disorders (SUDs) impact everything about an individual's life-health, family, employment, education, housing, transportation, and finances. By the time individuals with SUDs begin treatment-especially in publicly funded programs-most have few financial resources. Many have resorted to property crimes, resulting in fines, fees, and restitution costs that compound their financial difficulties. Reestablishing financial functioning is key to recovering from the consequences of addiction. Yet access to cash may also trigger relapses-especially in early recovery. Objective: This paper reports initial results from studies exploring how clients in treatment for SUDs manage their financial responsibilities, assessing their financial capability both in terms of access to financial services and personal financial literacy. Method: Using data collected between June 2017 and October 2019 from almost 5,000 SUD clients as they entered treatment as well as a financial needs assessment study of 70 clients during treatment, we conducted Chi-square testing and logistic regressions to analyze the relationships between client characteristics and financial capability. Results: Our results indicated that over 50% of individuals in addiction treatment did not have access to accounts at insured financial institutions, and that clients' ages and education levels were significantly related to their financial capability. We also found that 78% of clients feel that money management skills are important to their recovery. Conclusions: Many SUD clients in recovery have limited financial capability, and they are interested in developing financial skills. Increasing client financial capability may be an underemphasized, yet important part of recovery capital.

Unilateral parietal brain injury increases risk-taking on a rat gambling task

Traumatic brain injury (TBI) affects millions of individuals every year. Many of these injuries lead to lasting effects, particularly impairments in domains broadly classified as executive functions, such as impulse control and decision-making. While these impairments have been historically associated with frontal brain damage, other injuries such as concussion or parietal injury also contribute to similar dysfunction. However, it is unknown whether animal models of TBI would replicate these broad effects that are observed in human patients. In the current study, we delivered a unilateral parietal controlled cortical impact injury and assessed the performance of rats on a motoric task (rotarod) and a test of decision-making and impulsivity (rodent gambling task). TBI rats demonstrated significant motor impairments on the rotarod task; however, this did not extend to difficulties inhibiting motor actions (impulsivity). In addition, TBI caused chronic alterations to risk-based decision-making, extending out to 12 weeks post-injury. Specifically, rats with TBI preferred the riskiest, and most suboptimal option over all others. The current data suggest that models of unilateral TBI are sufficient for replicating some aspects of executive dysfunction (risky decision-making), while others are limited to frontal damage (impulsivity). These models may be used to develop therapeutics targeted at the chronic post-injury period when these symptoms often manifest in patients, a critically understudied area in preclinical TBI research.

Executive (dys)function after traumatic brain injury: special considerations for behavioral pharmacology

Executive function is an umbrella term that includes cognitive processes such as decision-making, impulse control, attention, behavioral flexibility, and working memory. Each of these processes depends largely upon monoaminergic (dopaminergic, serotonergic, and noradrenergic) neurotransmission in the frontal cortex, striatum, and hippocampus, among other brain areas. Traumatic brain injury (TBI) induces disruptions in monoaminergic signaling along several steps in the neurotransmission process - synthesis, distribution, and breakdown - and in turn, produces long-lasting deficits in several executive function domains. Understanding how TBI alters monoamingeric neurotransmission and executive function will advance basic knowledge of the underlying principles that govern executive function and potentially further treatment of cognitive deficits following such injury. In this review, we examine the influence of TBI on the following measures of executive function - impulsivity, behavioral flexibility, and working memory. We also describe monoaminergic-systems changes following TBI. Given that TBI patients experience alterations in monoaminergic signaling following injury, they may represent a unique population with regard to pharmacotherapy. We conclude this review by discussing some considerations for pharmacotherapy in the field of TBI.

Inequality in personality and temporal discounting across socioeconomic status? Assessing the evidence

Personality traits such as conscientiousness and impulsivity correlate with temporal discounting, the degree to which individuals discount the value of future relative to present rewards. These variables have, in turn, been hypothesized to relate to income inequality in the United States. A key but untested assumption of this hypothesis is that the association among these variables is distinct across socioeconomic classes. The purpose of the present research is to test that assumption. N = 1,100 adults with annual income ranging from at or below the poverty line ($0-$20,000) to upper-middle class ($200,000+) completed personality measures and a measure of temporal discounting. The results of our preregistered analyses indicated a positive association of income with trait planfulness, and a negative association with trait impulsivity and one parameter of temporal discounting that captures a bias to prefer sooner rewards to a greater degree if they are delivered that day. Our results can inform psychological theories of inequality and a broader conversation about effective public policy.

Does delay discounting predict maladaptive health and financial behaviors in smokers?

OBJECTIVE

Excessive delay discounting, the rapid devaluation of future rewards, is often demonstrated by individuals suffering from substance use disorders, including chronic cigarette smokers. This constricted temporal window not only produces increased valuation of immediate unhealthy rewards (e.g., cigarettes) but also a decreased valuation of both future healthy rewards (e.g., increased energy) and future consequences (e.g., lung cancer). Moreover, in addition to cigarettes, smokers tend to engage in other behaviors that elicit immediate rewards and negative future consequences such as overconsuming alcohol, unhealthy eating, physical inactivity, and/or irresponsible spending. The present study sought to determine whether smokers' discounting rate would predict the frequency of engagement in other poor health and financial behaviors, independent of cigarette smoking.

METHOD

A total of 303 daily smokers were asked to complete a delay discounting task and then answer how frequently they typically engaged in health and finance related behaviors.

RESULTS

A structural equation model was used to group the questions into highly significantly latent factors of "Drug Use," "Finances," "Fitness," "Food," "Health," "Household Savings," "Personal Development," and "Safe Driving." When regressed on the model, delay discounting significantly predicted engagement all of the factors, except "Safe Driving," independent of smoking status.

CONCLUSION

In sum, these findings highlight delay discounting as a useful metric for predicting whether individuals' engagement in variety of healthy physical and financial behaviors, as a function of their temporal window. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Reduction in delay discounting due to nicotine and its attenuation by cholinergic antagonists in Lewis and Fischer 344 rats

RATIONALE

Nicotine acts as an agonist for nicotinic acetylcholine receptors (nAChRs), and mecamylamine, a nonselective nAChR antagonist, attenuates effects of nicotine on delay discounting in some rat strains; whether nicotine's attenuation is specific to nAChR antagonism is unknown.

OBJECTIVE

During experiment 1, we evaluated dose-dependent effects of nicotine on delay discounting of pair-housed Lewis (LEW) and Fischer 344 (F344) rats. During experiment 2, we examined the sensitivity of nicotine's effects on delay discounting to pharmacological antagonism of nAChRs or muscarinic AChRs (mAChRs).

MATERIALS AND METHODS

Male LEW and F344 were trained to choose between one food pellet delivered immediately and three food pellets delivered after an increasing delay. During experiment 1, saline and nicotine (0.1-1.0 mg/kg) were tested acutely. During experiment 2, mecamylamine (0.25-1.0 mg/kg) or a nonselective mAChR antagonist, scopolamine (0.01-0.056 mg/kg), was administered prior to nicotine administration.

RESULTS

Nicotine dose dependently reduced delay discounting for both rat strains, and no strain differences were observed (ΔAUC = + 107% for 1.0 mg/kg and + 69.6% for 0.3 mg/kg relative to saline). At some doses, pretreatment with mecamylamine (range ΔAUC = - 27.6 to - 7.3%) or scopolamine (range ΔAUC = - 0.74 to - 51.6%) significantly attenuated the nicotine-induced reduction in some measures of delay discounting for both strains.

CONCLUSIONS

Results from experiment 1 suggest that when LEW and F344 are pair housed, there are no strain differences in delay discounting in response to nicotine. Results from experiment 2 suggest that attenuation of nicotine's effects on delay discounting may not be specific to nAChR antagonism.

Earning, Spending, and Drug Use in a Therapeutic Workplace

Drug addiction is a chronic, relapsing health problem that is associated with the degree to which individuals choose small, immediate monetary outcomes over larger, delayed outcomes. This study was a secondary analysis exploring the relation between financial choices and drug use in opioid-dependent adults in a therapeutic workplace intervention. Sixty-seven participants were randomly assigned to a condition in which access to paid job training was contingent upon naltrexone adherence (N = 35) or independent of naltrexone adherence (N = 32). Participants could earn approximately $10 per hour for 4 hours every weekday and could exchange earnings for gift cards or bill payments each weekday. Urine was collected and tested for opiates and cocaine thrice weekly. Participants' earning, spending, and drug use were not related to measures of delay discounting obtained prior to the intervention. When financial choices were categorized based on drug use during the intervention, however, those with less frequent drug use or frequent use of one drug spent a smaller proportion of their daily earnings and maintained a higher daily balance than those who frequently tested positive for both drugs (i.e., opiates and cocaine). Several patterns described the relation between cumulative earning and spending including no saving, periods of saving, and sustained saving. One destructive effect of drug use may be that it creates a perpetual zero-balance situation in the lives of users, which in turn prevents them from gaining materials that could help to break the cycle of addiction.

Model-free functional connectivity and impulsivity correlates of alcohol dependence: a resting-state study

Alcohol dependence is characterized by impulsiveness toward consumption despite negative consequences. Although neuro-imaging studies have implicated some regions underlying this disorder, there is little information regarding its large-scale connectivity pattern. This study investigated the within- and between-network functional connectivity (FC) in alcohol dependence and examined its relationship with clinical impulsivity measures. Using probabilistic independent component analysis on resting-state functional magnetic resonance imaging (rs-fMRI) data from 25 alcohol-dependent (AD) and 26 healthy control (HC) participants, we compared the within- and between-network FC between AD and HC. Then, the relationship between FC and impulsiveness as measured by the Barratt Impulsiveness Scale (BIS-11), the UPPS-P Impulsive Scale and the delay discounting task (DDT), was explored. Compared with HC, AD exhibited increased within-network FC in salience (SN), default mode (DMN), orbitofrontal cortex (OFCN), left executive control (LECN) and amygdala-striatum (ASN) networks. Increased between-network FC was found among LECN, ASN and SN. Between-network FC correlations were significantly negative between Negative-Urgency and OFCN pairs with right executive control network (RECN), anterior DMN (a-DMN) and posterior DMN (p-DMN) in AD. DDT was significantly correlated with the between-network FC among the LECN, a-DMN and SN in AD. These findings add evidence to the concept of altered within-network FC and also highlight the role of between-network FC in the pathophysiology of AD. Additionally, this study suggests differential neurobiological bases for different clinical measures of impulsivity that may be used as a systems-level biomarker for alcohol dependence severity and treatment efficacy.

Increased drug use and the timing of social assistance receipt among people who use illicit drugs

BACKGROUND

The monthly disbursement of social assistance (SA) payments to people who use illicit drugs (PWUD) has been temporally associated with increases in drug-related harm. Yet, whether SA receipt changes drug use intensity compared to levels of use at other times in the month has not been established. We therefore examined this relationship among PWUD in Vancouver, Canada (2005-2013).

METHODS

Data were derived from prospective cohorts of HIV-positive and HIV-negative PWUD. Every six months, participants were asked about their illicit drug use during the last 180 days and the past week. We determined whether SA receipt occurred within the assessment's one-week recall period. We employed generalized estimating equations controlling for confounders to examine the relationship between SA receipt and the change in drug use intensity, defined as a 100% increase in the average times per day a given drug was used in the last week compared to the previous 6 months. We tested the robustness of this relationship by stratifying analyses by whether individuals primarily used stimulants, illicit opioids or engaged in polydrug use and examining the timing of SA receipt relative to date of assessment.

RESULTS

Our study included 2661 individuals (median age 36, 32% female) with 1415 (53.2%) reporting SA receipt occurring within the one-week recall period of the assessment at least once. SA receipt was independently associated with intensified drug use (Adjusted Odds Ratio [AOR]: 1.79; 95% Confidence Interval [CI]: 1.53, 2.09), and remained significant when stratified by primary use of stimulants (AOR: 1.87; 95% CI: 1.54, 2.26), opioids (AOR: 1.96; 95% CI: 1.23, 3.13) and polydrug use (AOR: 1.53; 95% CI: 1.11, 2.10).

CONCLUSION

We found a temporal association between SA receipt and drug use intensification. While the health and social benefits of SA are significant, these findings suggest that alternative disbursement strategies, such as staggered or smaller and more frequent SA payments may be able to mitigate drug-related harm. Alternatives should be tested rigorously.

Factors Associated with Money Mismanagement Among Adults with Severe Mental Illness and Substance Abuse

People with severe mental illness often have substantial problems with money mismanagement such as losing or lending money to other people and making impulsive or unnecessary purchases, including drugs and alcohol. Money mismanagement in turn affects patients' health and social functioning, and can lead to homelessness and other harm. This cross-sectional study evaluated demographic and clinical predictors of money mismanagement among SSI/SSDI recipients. SSI/SSDI beneficiaries (N = 95) with recent cocaine use initiating a clinical trial were assessed at intake with demographic, cognitive, psychiatric, social/family, substance abuse, and financial measures. In multivariate regression analyses, psychiatric functioning and drug dependence diagnosis were independent predictors of self-reported money mismanagement. Even within individuals whom all had recently used cocaine, those with drug dependence and those with more psychiatric symptomatology had more difficulty managing their funds. Future studies might determine whether people who reduce their drug use and psychiatric symptomatology go on to better manage their funds.

Favorable associations with alcohol and impaired self-regulation: A behavioral economic analysis

BACKGROUND

Recent research has demonstrated that both poor self-regulation and favorable implicit associations toward alcohol can play important roles in predicting drinking. Less well studied, however, is how the interplay between implicit associations and self-regulation may impact decisions about alcohol consumption. Behavioral economics is one important tool that may provide insight into the cognitive processes that impact demand for alcohol and drinking decisions.

METHODS

Healthy young adult participants completed an Implicit Association Task (IAT) that measured the strength of associations between approach/avoid attributes and target alcohol/neutral images. Impaired self-regulation was assessed by a classic delay discounting task. Participants also completed an Alcohol Purchase Task (APT), which yields multiple behavioral economic indices, chief among which are intensity (the number of drinks a participant would consume if the drinks were free) and elasticity (the degree to which an increased per-drink price impacts the number of drinks consumed in a hypothetical drinking situation). Finally, participants completed a timeline follow-back assessment of past-90-day drinking.

RESULTS

Findings indicated that implicit approach associations toward alcohol predicted increased demand for alcohol on the APT. Although delay discounting did not have a direct effect on demand for alcohol, there was a significant interaction between IAT and delay discounting, such that higher implicit alcohol approach associations predicted particularly high demand for alcohol among participants with poorer self-regulation. APT and IAT, in turn, predicted self-reported drinking behavior.

CONCLUSIONS

These results suggest that favorable attitudes toward alcohol, together with poor self-regulation, can significantly impact drinking decisions in healthy young adults.

The genetics of impulsivity: evidence for the heritability of delay discounting

BACKGROUND

Delay discounting (DD), a decline in the subjective value of reward with increasing delay until its receipt, is an established behavioral model of impulsive choice, a key component of a broader impulsivity construct. Greater DD, i.e., a tendency to choose smaller immediate over larger delayed rewards, has been implicated as a potential intermediate phenotype (endophenotype) for addictive disorders and comorbid externalizing psychopathology, particularly in adolescence. However, genetic and environmental origins of DD remain unclear. Accordingly, the goal of the present study was to assess heritability of DD, an important aspect of its utility as an endophenotype.

METHODS

A commonly used computerized procedure involving choice between varying amounts of money available immediately and a standard amount of $100 presented at variable delays was administered to a population-based sample of twins aged 16 and 18 (n = 560, including 134 monozygotic and 142 dizygotic pairs). DD was quantified using area under the discounting curve and the k coefficient estimated by fitting a hyperbolic model to individual data. Heritability was assessed using linear structural equation modeling of twin data.

RESULTS

The genetic analysis revealed significant heritability of both DD measures (area under the discounting curve: 46% and 62%; k: 35% and 55% at age 16 and 18, respectively).

CONCLUSIONS

The present study provides evidence for heritability of both model-based and model-free DD measures and suggests that DD is a promising intermediate phenotype for genetic dissection of impulsivity and externalizing spectrum disorders.

Choice impulsivity: Definitions, measurement issues, and clinical implications

Impulsivity critically relates to many psychiatric disorders. Given the multifaceted construct that impulsivity represents, defining core aspects of impulsivity is vital for the assessment and understanding of clinical conditions. Choice impulsivity (CI), involving the preferential selection of smaller sooner rewards over larger later rewards, represents one important type of impulsivity. The International Society for Research on Impulsivity (InSRI) convened to discuss the definition and assessment of CI and provide recommendations regarding measurement across species. Commonly used preclinical and clinical CI behavioral tasks are described, and considerations for each task are provided to guide CI task selection. Differences in assessment of CI (self-report, behavioral) and calculating CI indices (e.g., area-under-the-curve, indifference point, and steepness of discounting curve) are discussed along with properties of specific behavioral tasks used in preclinical and clinical settings. The InSRI group recommends inclusion of measures of CI in human studies examining impulsivity. Animal studies examining impulsivity should also include assessments of CI and these measures should be harmonized in accordance with human studies of the disorders being modeled in the preclinical investigations. The choice of specific CI measures to be included should be based on the goals of the study and existing preclinical and clinical literature using established CI measures.

Behavioral modeling of human choices reveals dissociable effects of physical effort and temporal delay on reward devaluation

There has been considerable interest from the fields of biology, economics, psychology, and ecology about how decision costs decrease the value of rewarding outcomes. For example, formal descriptions of how reward value changes with increasing temporal delays allow for quantifying individual decision preferences, as in animal species populating different habitats, or normal and clinical human populations. Strikingly, it remains largely unclear how humans evaluate rewards when these are tied to energetic costs, despite the surge of interest in the neural basis of effort-guided decision-making and the prevalence of disorders showing a diminished willingness to exert effort (e.g., depression). One common assumption is that effort discounts reward in a similar way to delay. Here we challenge this assumption by formally comparing competing hypotheses about effort and delay discounting. We used a design specifically optimized to compare discounting behavior for both effort and delay over a wide range of decision costs (Experiment 1). We then additionally characterized the profile of effort discounting free of model assumptions (Experiment 2). Contrary to previous reports, in both experiments effort costs devalued reward in a manner opposite to delay, with small devaluations for lower efforts, and progressively larger devaluations for higher effort-levels (concave shape). Bayesian model comparison confirmed that delay-choices were best predicted by a hyperbolic model, with the largest reward devaluations occurring at shorter delays. In contrast, an altogether different relationship was observed for effort-choices, which were best described by a model of inverse sigmoidal shape that is initially concave. Our results provide a novel characterization of human effort discounting behavior and its first dissociation from delay discounting. This enables accurate modelling of cost-benefit decisions, a prerequisite for the investigation of the neural underpinnings of effort-guided choice and for understanding the deficits in clinical disorders characterized by behavioral inactivity.

One of the main functions of the brain is to select sequences of actions that lead to rewarding outcomes (e.g., food). However, such rewards are often not readily available; instead physical effort may be required to obtain them, or their arrival may be delayed. The ability to integrate the costs and benefits of potential courses of action is severely impaired in several common disorders, such as depression and schizophrenia. Mathematical models can describe how individuals depreciate rewards based on the costs associated with them. For example, models of how a reward loses appeal with increasing temporal delays can provide individual impulsivity scores, and can serve as a predictor of financial mismanagement. To date, there is no established model to describe accurately how humans depreciate rewards when obtaining them requires physical effort. This is surprising given the prevalence of disorders related to a diminished willingness to exert effort. Here we derive a biologically plausible mathematical model that can describe how healthy humans make decisions tied to physical efforts. We show that effort and delay influence reward valuation in different ways, contrary to common assumptions. Our model will be important for characterizing decision-making deficits in clinical disorders characterized by behavioral inactivity.

Delay discounting rates: a strong prognostic indicator of smoking relapse

BACKGROUND

Recent evidence suggests that several dimensions of impulsivity and locus of control are likely to be significant prognostic indicators of relapse.

METHOD

One-hundred and thirty-one treatment seeking smokers were enrolled in six weeks of multi-component cognitive-behavioral therapy with eight weeks of nicotine replacement therapy.

ANALYSIS

Cox proportional hazard regressions were used to model days to relapse with each of the following: delay discounting of $100, delay discounting of $1000, six subscales of the Barratt Impulsiveness Scale (BIS), Rotter's Locus of Control (RLOC), Fagerstrom's Test for Nicotine Dependence (FTND), and the Perceived Stress Scale (PSS). Hazard ratios for a one standard deviation increase were estimated with 95% confidence intervals for each explanatory variable. Likelihood ratios were used to examine the level of association with days to relapse for different combinations of the explanatory variables while accounting for nicotine dependence and stress level.

RESULTS

These analyses found that the $100 delay discounting rate had the strongest association with days to relapse. Further, when discounting rates were combined with the FTND and PSS, the associations remained significant. When the other measures were combined with the FTND and PSS, their associations with relapse non-significant.

CONCLUSIONS

These findings indicate that delay discounting is independently associated with relapse and adds to what is already accounted for by nicotine dependence and stress level. They also signify that delay discounting is a productive new target for enhancing treatment for tobacco dependence. Consequently, adding an intervention designed to decrease discounting rates to a comprehensive treatment for tobacco dependence has the potential to decrease relapse rates.

Computational heterogeneity in the human mesencephalic dopamine system

Recent evidence in animals has indicated that the mesencephalic dopamine system is heterogeneous anatomically, molecularly, and functionally, and it has been suggested that the dopamine system comprises distinct functional systems. Identifying and characterizing these systems in humans will have widespread ramifications for understanding drug addiction and mental health disorders. Model-based studies in humans have suggested an analogous computational heterogeneity, in which dopaminergic targets in striatum encode both experience-based learning signals and counterfactual learning signals that are based on hypothetical information. We used brainstem-tailored fMRI to identify mesencephalic sources of experiential and counterfactual learning signals. Participants completed a decision-making task based on investing in markets. This sequential investment task generated experience-based learning signals, in the form of temporal difference (TD) reward prediction errors, and counterfactual learning signals, in the form of “fictive errors.” Fictive errors are reinforcement learning signals based on hypothetical information about “what could have been.” An additional learning signal was constructed to be relatable to a motivational salience signal. Blood oxygenation level dependent responses in regions of substantia nigra (SN) and ventral tegmental area (VTA), where dopamine neurons are located, coded for TD and fictive errors, and additionally were related to the motivational salience signal. These results are highly consistent with animal electrophysiology and provide direct evidence that human SN and VTA heterogeneously handle important reward-harvesting computations.

Test-retest reliability of behavioral measures of impulsive choice, impulsive action, and inattention

Behavioral measures of impulsivity are widely used in substance abuse research, yet relatively little attention has been devoted to establishing their psychometric properties, especially their reliability over repeated administration. The current study examined the test-retest reliability of a battery of standardized behavioral impulsivity tasks, including measures of impulsive choice (i.e., delay discounting, probability discounting, and the Balloon Analogue Risk Task), impulsive action (i.e., the stop signal task, the go/no-go task, and commission errors on the continuous performance task), and inattention (i.e., attention lapses on a simple reaction time task and omission errors on the continuous performance task). Healthy adults (n = 128) performed the battery on two separate occasions. Reliability estimates for the individual tasks ranged from moderate to high, with Pearson correlations within the specific impulsivity domains as follows: impulsive choice (r range: .76-.89, ps < .001); impulsive action (r range: .65-.73, ps < .001); and inattention (r range: .38-.42, ps < .001). Additionally, the influence of day-to-day fluctuations in mood, as measured by the Profile of Mood States, was assessed in relation to variability in performance on each of the behavioral tasks. Change in performance on the delay discounting task was significantly associated with change in positive mood and arousal. No other behavioral measures were significantly associated with mood. In sum, the current analysis demonstrates that behavioral measures of impulsivity are reliable measures and thus can be confidently used to assess various facets of impulsivity as intermediate phenotypes for drug abuse.

Posttraumatic stress disorder increases sensitivity to long term losses among patients with major depressive disorder

BACKGROUND

Decisions under risk and with outcomes that are delayed in time are ubiquitous in real life and can have a significant impact on the health and wealth of the decision-maker. Despite its potential relevance for real-world choices, the degree of aberrant risky and intertemporal decision-making in patients suffering from major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) has received little attention to date.

METHOD

We used a case-control design to compare decision-making in healthy control subjects (N=16) versus untreated depressed subjects in a current major depressive episode (N=20). In order to examine how major depressive disorder (MDD) may impact decision-making, subjects made decisions over (1) risky outcomes and (2) delayed outcomes in the domain of gains and losses using choice paradigms from neuroeconomics. In a pre-planned analysis, depressed subjects were subdivided into those with primary PTSD along with comorbid MDD (MDD+PTSD) versus those with primary MDD without PTSD (MDD-only). Choice behavior was modeled via a standard econometric model of intertemporal choice, a quasi-hyperbolic temporal discounting function, which was estimated for each subject group separately.

RESULTS

Under conditions of potential gain, depressed subjects demonstrated greater discounting for gains across all time frames compared to controls. In the realm of losses, both subgroups of depressed subjects discounted more steeply than controls for short time frames. However, for delayed losses ranging from >1-10 years, MDD+PTSD subjects showed shallower discounting rates relative to MDD-only subjects, who continued to discount future losses steeply. Risk attitudes did not contribute to differences in intertemporal choice.

CONCLUSIONS

Depressed patients make choices that minimize current pain and maximize current reward, despite severe later consequences or lost opportunities. Anxiety associated with PTSD may serve as a partially protective factor in decision-making about long-term potential losses compared to MDD patients without PTSD.

The biological effects of acute psychosocial stress on delay discounting

Organisms prefer to receive rewards sooner rather than later because they excessively discount the subjective value of future rewards, a phenomenon called delay discounting. Recent studies have reported an association between cortisol-which is secreted by the hypothalamic-pituitary-adrenal (HPA) axis-and delay discounting. However, no study has examined whether acutely induced psychosocial stress modulates delay discounting. Thus, the present study examined the effect of acute psychosocial stress and its hormonal and inflammatory correlates on the rate of delay discounting. To accomplish this purpose, we assessed the participants' discounting rates using the questionnaire version with inter-temporal choice before and after an acute psychosocial stress task (the Trier Social Stress Test; TSST). The results demonstrated that TSST increased rates of delay discounting in only cortisol responders (not in non-responders), indicating the possible influence of the pathway from the HPA axis to the dopaminergic systems under acute stress. Furthermore, the findings of correlation analysis indicated a U-shaped relationship between baseline level of C-reactive protein and delay discounting rate, suggesting a complex relationship between inflammatory markers and delay discounting rate.

Discounting the value of safety: effects of perceived risk and effort

INTRODUCTION

Although falls from heights remain the most prevalent cause of fatalities in the construction industry, factors impacting safety-related choices associated with work at heights are not completely understood. Better tools are needed to identify and study the factors influencing safety-related choices and decision making.

METHOD

Using a computer-based task within a behavioral economics paradigm, college students were presented a choice between two hypothetical scenarios that differed in working height and effort associated with retrieving and donning a safety harness. Participants were instructed to choose the scenario in which they were more likely to wear the safety harness. Based on choice patterns, switch points were identified, indicating when the perceived risk in both scenarios was equivalent.

RESULTS

Switch points were a systematic function of working height and effort, and the quantified relation between perceived risk and effort was described well by a hyperbolic equation.

CONCLUSION

Choice patterns revealed that the perceived risk of working at heights decreased as the effort to retrieve and don a safety harness increased.

IMPACT ON INDUSTRY

Results contribute to the development of computer-based procedure for assessing risk discounting within a behavioral economics framework. Such a procedure can be used as a research tool to study factors that influence safety-related decision making with a goal of informing more effective prevention and intervention strategies.

Overview of special sub-section on money management articles: cross-disciplinary perspectives on money management by addicts

BACKGROUND

How addicts manage their funds can be understood from the studies of impulsive spending, contingency management, self-reported expenditures, behavioral economics, and anthropology.

OBJECTIVE

To show how these differing perspectives can provide theoretical explanations for substance abuse, they were applied to the question of when extra "windfall" funds are spent on substances of abuse. Treatment implications of these perspectives were examined.

METHODS

Relevant literature was reviewed.

RESULTS

Behavioral economics and related approaches provide the basis for money-management-based interventions targeting substance abuse, informed configuration of reinforcers to compete with substances, and therapeutically framing the choice between abstinence and substance use.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

A cross-discipline consideration of how addicts manage their funds has the potential to inform and improve substance abuse treatment.