Delay discounting decreases in those completing treatment for opioid dependence

Associations between delay discounting and unhealthy behaviors in substance use recovery

BACKGROUND

Research on delay discounting (DD) is mixed on whether DD is a domain-specific component related to specific behaviors or a domain-general process that cuts across various behaviors. A pivotal group to test the associations between DD and unhealthy behaviors is individuals in recovery from substance use disorders (SUD), as they are moving away from a disorder toward a healthier state.

METHODS

Individuals in SUD recovery (n = 317) completed the Temptation Scale, the Health Behaviors Questionnaire, and an Adjusting Delay Discounting Task. An exhaustive model space search was performed using linear regression to examine associations between DD with temptation, engagement in unhealthy behaviors, and the total number of unhealthy behaviors participants engage in. We also tested whether remission status is associated with the total number of unhealthy behaviors participants engage in.

RESULTS

Results revealed that DD was positively associated with poor eating (p<.001), physical inactivity (p=.003), financial irresponsibility (p<.001), risky behaviors (p<.001), lack of personal development goals (p<.001), lack of household savings (p=.004), and lack of health behaviors (p=.003). DD was also positively associated with the total number of unhealthy behaviors participants engage in (p<.001). Participants who were not in remission engaged in more unhealthy behaviors compared to those who were in remission (p<.001).

CONCLUSION

In a sample of individuals in recovery from SUD, DD is not domain-specific and undergirds engagement in several maladaptive health behaviors that can negatively impact recovery. Thus, DD can be a target for interventions aiming to reduce other maladaptive behaviors in SUD recovery.

The Use of Nonmonetary Outcomes in Health-Related Delay Discounting Research: Review and Recommendations

Delay discounting (DD) refers to the tendency to devalue an outcome as a function of its delay. Most contemporary human DD research uses hypothetical money to assess individual rates of DD. However, nonmonetary outcomes such as food, substances of misuse, and sexual outcomes have been used as well, and have advantages because of their connections to health. This article reviews the literature on the use of nonmonetary outcomes of food, drugs, and sexual outcomes in relation to health and reinforcer pathologies such as substance use disorders, obesity, and sexual risk behaviors, respectively, and makes a case for their use in discounting research. First, food, substances, and sex may be more ecologically valid outcomes than money in terms of their connections to health problems and reinforcer pathologies. Second, consistent trends in commodity-specific (i.e., domain) effects, in which nonmonetary outcomes are discounted more steeply than money, enhance variation in discounting values. Third, commodity-specific changes in discounting with treatments designed to change health choices are described. Finally, methodological trends such as test-retest reliability, magnitude effects, the use of hypothetical versus real outcomes, and age-related effects are discussed in relation to the three outcome types and compared to trends with monetary discounting. Limitations that center around individual preferences, nonsystematic data, and deprivation are discussed. We argue that researchers can enhance their DD research, especially those related to health problems and reinforcer pathologies, with the use of nonmonetary outcomes. Recommendations for future directions of research are delineated.

The Impact of Monetary Incentives on Delay Discounting Within a Year-Long Physical Activity Intervention

BACKGROUND

Delay discounting is the depreciation in a reward's perceived value as a function of the time until receipt. Monetary incentive programs that provide rewards contingent on meeting daily physical activity (PA) goals may change participants' delay discounting preferences.

PURPOSE

Determine if monetary incentives provided in close temporal proximity to meeting PA goals changed delay discounting, and if such changes mediated intervention effects.

METHODS

Inactive adults (n = 512) wore accelerometers during a 12-month intervention where they received proximal monetary incentives for meeting daily moderate-to-vigorous PA (MVPA) goals or delayed incentives for study participation. Delay discount rate and average MVPA were assessed at baseline, end of intervention, and a 24-month follow-up. Using structural equation modeling, we tested effects of proximal versus delayed rewards on delay discounting and whether any changes mediated intervention effects on MVPA. PA self-efficacy was also evaluated as a potential mediator, and both self-efficacy and delay discounting were assessed as potential moderators of intervention effects.

RESULTS

Proximal rewards significantly increased participants' delay discounting (β = 0.238, confidence interval [CI]: -0.078, 0.380), indicating greater sensitivity to reinforcement timing. This change did not mediate incentive-associated increases in MVPA at the end of the 12-month intervention (β = -0.016, CI: -0.053, 0.019) or at a 24-month follow-up (β = -0.020, CI: -0.059, 0.018). Moderation effects were not found.

CONCLUSIONS

Incentive-induced increases in delay discounting did not deleteriously impact MVPA. This finding may help assuage concerns about using monetary incentives for PA promotion, but further research regarding the consequences of changes in delay discounting is warranted.

Delay discounting and substance use treatment outcomes: A systematic review focused on treatment outcomes and discounting methodology

INTRODUCTION

Delay discounting-the tendency to choose small, immediate rewards over larger, delayed rewards-is robustly associated with substance use. Delay discounting may present challenges in treatment for substance use disorders, as individuals with elevated discounting may struggle to wait for the long-term rewards that come from abstinence, which may yield poorer treatment outcomes. However, evidence on the role of discounting in treatment outcomes has been inconsistent. The study conducted a systematic review of the literature to characterize the prospective effects of delay discounting measured pre-treatment on substance use treatment outcomes, with a focus on characterizing findings across: 1) type of treatment outcome and 2) methodology used to assess and characterize discounting.

METHOD

A systematic literature search identified N = 17 studies that examined the association between delay discounting at treatment entry (pre-treatment) and substance use treatment outcomes. Findings were reported across the following substance use treatment outcomes: abstinence, relapse, use frequency and related problems, and treatment adherence. Findings regarding discounting methodology were reported by type of discounting measure (adjusting choice task, fixed choice task, or experiential task) and parameter used to characterize discounting (k, log transformed k (lnk), and area under the curve).

RESULTS

Delay discounting at treatment entry was not consistently associated with substance use treatment outcomes when examined across all studies overall (47 %) or by treatment outcome (0-40 % for most outcomes). The majority of studies (64 %) that used an adjusting choice, computer-based task reported a significant association between discounting and treatment outcomes, whereas few studies that used a fixed choice or experiential task reported significant associations with treatment outcomes (0-25 %). Most studies (71 %) that used the lnk parameter to characterize discounting reported significant associations between discounting and a range of treatment outcomes. In contrast, few studies that used k or AUC (25-33 %) reported significant associations between discounting and treatment outcomes.

CONCLUSION

When examined overall and by treatment outcome, evidence did not consistently indicate that delay discounting was prospectively associated with substance use treatment outcomes. However, delay discounting at treatment entry was more commonly associated with a variety of poorer treatment outcomes when researchers used more fine-grained methods to characterize discounting.

The Associations between Remission Status, Discounting Rates, and Recovery from Substance Use Disorders

Background: Recovery from substance use disorders (SUDs) requires sustained and purposeful support to maintain long-term remission. Methods: This study investigated the association between assessment of recovery capital, household chaos, delay discounting (DD) and probability discounting (PD), and remission status among individuals in recovery from SUD. Data from 281 participants from the International Quit & Recovery Registry (IQRR), an ongoing online registry that aims to study the recovery process, were included in the analysis. Results: Lower DD rates and higher recovery capital were found among those in remission compared to those not in remission after controlling for demographics. In contrast, the association of household chaos and PD with remission status were insignificant. Overall, DD accounted for 20% of the total effect between the recovery capital and the remission status. Conclusion: This study contributes to the understanding of recovery as a multidimensional process, supports DD as a behavioral marker of addiction, and suggests areas for future research.

Initial evaluation of domain-specific episodic future thinking on delay discounting and cannabis use

Episodic Future Thinking (EFT), mental simulation of personally relevant and positive future events, may modulate delay discounting (DD) in cannabis users. Whether EFT impacts cannabis use, whether DD mediates this effect, and whether EFT can be enhanced by prompting future events across specific life domains is unknown. Active, adult cannabis users (n = 90) recruited from Amazon mTurk and Qualtrics Panels were administered an Episodic Specificity Induction (ESI) to enhance quality of imagined events before being randomized to EFT, domain-specific-EFT (DS-EFT), or Episodic Recent Thinking (ERT). All participants created four, positive life events; DS-EFT participants imagined social, leisure, health, and financial events. Event-quality ratings were assessed (e.g., enjoyment). DD was assessed at baseline (Day 1), post-intervention (Days 2-4), and follow-up (Days 9-12). Cannabis use was assessed at baseline and follow-up. Differences in change in days and grams of cannabis use between conditions and mediation of changes in use by DD were examined. No differences in DD were observed between conditions. DS-EFT, but not EFT, showed significantly greater reductions in grams (d = .54) and days of cannabis use (d = .50) than ERT. DS-EFT and EFT demonstrated significantly greater event-quality ratings than ERT (ds > .55). EFT-based interventions showed potential for reducing cannabis use. Unexpectedly, effects on DD did not mediate this effect. Further testing with larger samples of cannabis users is needed to better understand EFT's mechanisms of action and determine optimal implementation strategies. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Examining associations between impulsivity, opioid use disorder, and posttraumatic stress disorder: The additive relation between disorders

Impulsivity is a key feature of opioid use disorder (OUD) and other psychiatric conditions, including posttraumatic stress disorder (PTSD). The relationship between disorders and impulsivity may be additive, such that individuals with multiple disorders exhibit greater impulsivity than those with a single disorder. However, the association between impulsivity, OUD, and PTSD is unclear. Accordingly, this study compared individuals with concurrent OUD and PTSD (OUD + PTSD; n = 55), OUD without PTSD (OUD-PTSD; n = 34), PTSD without OUD (n = 32), and healthy controls (HCs; n = 55) on the Short Urgency, Premeditation, Perseverance, Sensation Seeking, Positive Urgency Impulsive Behavior Scale (SUPPS-P), and the 27-item Monetary Choice Questionnaire (MCQ). With respect to the SUPPS-P, the OUD + PTSD, OUD-PTSD, and PTSD without OUD groups reported more impulsivity on the negative urgency, positive urgency, and lack of premeditation subscales compared to HCs (ps < .001). The OUD + PTSD group also reported greater negative urgency compared to the OUD-PTSD group (p = .001) and HCs (p < .001), but not the PTSD without OUD group (p = .07). Furthermore, participants with OUD + PTSD exhibited greater discounting of delayed rewards on the MCQ than those in the PTSD without OUD group and HCs (p's < .001). However, no significant differences were observed between the two OUD groups (p = .86). These results support impulsivity as a mechanism underlying both OUD and PTSD. Future research should examine whether interventions targeting impulsivity, emotion regulation, and delay discounting are associated with meaningful improvements in functioning among individuals with OUD and PTSD. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Age differences in the behavioural economics of cannabis use: Do adolescents and adults differ on demand for cannabis and discounting of future reward?

BACKGROUND

Adolescence is a period of psychological and neural development in which harms associated with cannabis use may be heightened. We hypothesised that adolescent who use cannabis (adolescentsWUC) would have steeper delay discounting (preference for immediate over future rewards) and greater demand (relative valuation) for cannabis than adults who use cannabis (adultsWUC).

METHODS

This cross-sectional study, part of the 'CannTeen' project, compared adultsWUC (n = 71, 26-29 years old) and adolescentsWUC (n = 76, 16-17 years old), and gender- and age-matched adolescent (n = 63) and adult (n = 64) controls. AdolescentsWUC and adultsWUC used cannabis 1-7 days/week and were matched on cannabis use frequency (4 days/week). The Monetary Choice Questionnaire assessed delay discounting. A modified Marijuana Purchase Task (MPT) assessed cannabis demand in adolescentsWUC and adultsWUC. The MPT yielded five indices: intensity (amount of cannabis used at zero cost), O_max (total peak expenditure), P_max (price at peak expenditure), breakpoint (cost at which cannabis demand is suppressed to zero) and elasticity (degree to which cannabis use decreases with increasing price). Analyses were adjusted for covariates of gender, socioeconomic status, other illicit drug use.

RESULTS

Both adolescentsWUC and adultsWUC had steeper delay discounting than controls (F, (1,254)= 9.13, p = 0.003, η_p²= 0.04), with no significant age effect or interaction. AdolescentsWUC showed higher intensity (F, (1,138)= 9.76, p = 0.002, η_p²= 0.07) and lower elasticity (F, (1,138)= 15.25, p < 0.001, η_p²= 0.10) than adultsWUC. There were no significant differences in P_max, O_max or breakpoint.

CONCLUSION

Individuals who use cannabis prefer immediate rewards more than controls. AdolescentsWUC, compared to adultsWUC, may be in a high-risk category with diminished sensitivity to cannabis price increases and a greater consumption of cannabis when it is free.

The phenotype of recovery VI: The association between life-history strategies, delay discounting, and maladaptive health and financial behaviors among individuals in recovery from alcohol use disorders

BACKGROUND

The life-history theory is a well-established framework that predicts behaviors and explains how and why organisms allocate effort and resources to different life goals. Delay discounting (DD) is associated with risky behaviors and has been suggested as a candidate behavioral marker of addiction. Thus, we investigated the relationship between DD, life-history strategies, and engagement in risky behaviors among individuals in recovery from alcohol use disorder (AUD).

METHODS

Data from 110 individuals in recovery from addiction from The International Quit & Recovery Registry, an ongoing online registry designed to understand recovery phenotype, were included in the analysis. The association between life-history strategies, DD, engagement in risky behaviors, and remission status were assessed.

RESULTS

Life-history strategy scores were significantly associated with DD rates and finance, health, and personal development behaviors after controlling for age, sex, race, ethnicity, years of education, marital status, smoking status, and history of other substance use. Remission status was significantly associated with life-history strategy, DD, drug use, fitness, health, and safe driving after controlling for age, sex, race, years of education, marital status, and smoking status. In addition, a mediation analysis using Hayes' methods revealed that the discounting rates partially mediated the association between remission status and life-history strategy scores.

CONCLUSIONS

Life-history strategies and remission status are both significantly associated with DD and various health and finance behaviors among individuals in recovery from AUD. This finding supports the characterizations of DD as a candidate behavioral marker of addiction that could help differentiate subgroups needing special attention or specific interventions to improve the outcomes of their recovery. Future longitudinal studies are warranted to understand the relationships between changes in life-history strategies, DD, maladaptive health behaviors, and remission status over time.

A Proof-of-Concept Ecological Momentary Assessment Study of Day-Level Dynamics in Value-Based Decision-Making in Opioid Addiction

BACKGROUND

Drug addiction is thought to be characterized by risky and impulsive behavior despite harmful consequences. Whether these aspects of value-based decision-making in people with addiction are stable and trait-like, and the degree to which they vary within-person and are sensitive to changes in psychological state, remains unknown. In this pilot study, we examined the feasibility of distinguishing these state- vs. trait-like components by probing day-level dynamics of risk and time preferences in patients with opioid use disorder (OUD) as they engaged with their natural environment.

METHODS

Twenty-three individuals with OUD receiving outpatient treatment (40% female; M = 45.67 [SD = 13.16] years of age) and twenty-one matched healthy community controls (47% female; M = 49.67 [SD = 14.38] years of age) participated in a 28-day smartphone-based ecological momentary assessment study (1085 person days; M = 24.66, SD = 5.84). Random prompts administered daily assessed subjects' psychological state (e.g., mood) and economic preferences for real delayed and risky monetary rewards.

RESULTS

Subjects demonstrated dynamic decision-making preferences, with 40-53% of the variation in known risk and ambiguity tolerance, and 67% in discounting, attributable to between-person vs. within-person (day-to-day) differences. We found that changes in psychological state were related to changes in risk preferences, with patients preferring riskier offers on days they reported being in a better mood but no differences between groups in aggregate level behavior. By contrast, temporal discounting was increased overall in patients compared to controls and was unrelated to global mood. The study was well-tolerated, but compliance rates were moderate and lower in patients.

CONCLUSION

Our data support the idea that decision-making preferences in drug addiction exhibit substantial within-person variability and that this variability can be well-captured using remote data collection methods. Preliminary findings suggested that aspects of decision-making related to consideration of risk may be more sensitive to within-person change in global psychological state while those related to consideration of delay to reward, despite also being somewhat variable, stably differ from healthy levels. Identifying the cognitive factors that contribute to opioid use risk in a "real-world" setting may be important for identifying unique, time-sensitive targets for intervention.

Reward-Related Decision-Making in Current and Past Disordered Gambling: Implications for Impulsive Choice and Risk Preference in the Maintenance of Gambling Disorder

Impulsive reward-related decision-making (RRDM) is robustly associated with gambling disorder (GD), although its role in the development and perpetuation of GD is still being investigated. This project sought to examine the possible roles of impulsive and risky choice, two aspects of RRDM, in the perpetuation of GD. Additionally, the potential moderating role of comorbid substance misuse was considered. A total of 434 participants with symptoms of current GD and symptoms of concurrent substance use disorder (SUD; n = 105), current GD with past SUD (n = 98), past GD with current SUD (n = 53), or past GD with past substance use disorder (SUD; n = 92), and 96 healthy controls were recruited through MTurk. Participants completed a randomly adjusting delay discounting (a measure of impulsive choice) and probabilistic discounting (a measure of risky choice) task and self-report questionnaires of gambling participation, GD and SUD symptomology, and trait impulsivity. Although control participants showed significantly greater delay discounting compared to individuals with a current or history of GD, no significant group differences emerged between individuals with current GD or a history of GD. Individuals with current GD showed significantly less probabilistic discounting compared to individuals with a history of GD and control participants showed the greatest rates of probabilistic discounting. These effects remained after controlling for lifetime gambling symptom severity and trait impulsivity. Overall, these findings suggest a potential maintaining role of risky choice in gambling disorder, but do not support a maintaining role for impulsive choice.

Contemporary methods in delayed discounting: Applications for suicidology with simulation

OBJECTIVE

To present an approach for integrating recently developed methods in behavioral economics into suicidology research. At present, existing applications of delay discounting in suicidology have focused predominantly on hypothetical choices related to monetary value as a proxy to "risky" choices linked to unsafe or suicidal behavior. In this report, we outline a more targeted approach that directly indexes choices related to treatment in suicide prevention initiatives and incorporates the strengths afforded by multi-level modeling. This more targeted approach precludes the need for multi-step comparisons (improving power), avoids compressing choice variability across delays into individual values (improving precision), and better accommodates decision-making at the upper and lower extremes (improving reliability).

METHOD

We present this analytical approach within the context of a Hypothetical Firearm Decision-making Task with simulated participants. A simulated study is provided to illustrate how this approach can be used to evaluate how individuals make temporally delayed decisions related to treatment for suicidal behavior (i.e., temporarily limiting their access to firearms while undergoing treatment).

RESULTS AND CONCLUSIONS

The results of this simulated study are provided to illustrate how more advanced behavioral decision-making models can be used to supplement existing research methods in suicidology.

Envisioning a future: Values clarification in early recovery from opioid use disorder

High rates of relapse and overdose during early recovery from opioid use disorder (OUD) highlight the importance of providing effective treatment during this crucial phase. While early treatment often focuses on managing urges and withdrawal symptoms, eliciting personally salient motivators may help to target predictors of treatment outcomes such as motivation and self-efficacy. This experimental study examined the effect of a brief values clarification exercise on motivation and self-efficacy for abstinence in a sample of n = 93 individuals in brief residential treatment for OUD. Participants were randomly assigned to values clarification or a time management control condition exercise. Self-efficacy for abstinence as measured by a validated single-item measure was higher for participants in the values condition (M = 8.7) compared to control (M = 7.8, p = .013), while motivation for abstinence as measured by the commitment to sobriety scale was similarly high for both the values clarification (M = 28.0) and control (M = 27.8, p = .642) groups. There were no group differences in delay discounting, the theorized mediator of these relationships. Taken together, these results suggest that even a brief values clarification exercise may increase self-efficacy for abstinence when added to early residential treatment for OUD.

Long-term changes in delay discounting following a smoking cessation treatment for patients with depression

BACKGROUND

Delay discounting (DD) has been identified as a trans-disorder process underlying addictive behaviors, including smoking. Previous studies have evaluated how different treatments for drug dependence have affected DD, showing mixed results. Furthermore, no study has examined the effects of changes in depression on DD rates. The aim of this study was to evaluate the impact of treatment type: cognitive behavioral treatment (CBT), CBT + behavioral activation (BA), or CBT + BA + contingency management (CM), and changes in smoking status and depression on DD rates in long-term follow-up among a sample of treatment-seeking smokers with depression.

METHODS

Participants were 180 treatment-seeking smokers with depression who were randomly assigned to one of the following treatment conditions: CBT (n = 60), CBT + BA (n = 60), and CBT + BA + CM (n = 60). Depressive symptomatology and major depression diagnosis were evaluated through the BDI-II and the SCID-I of the DSM-IV-TR. DD rates were assessed using the DD task with hypothetical monetary rewards. Smoking status, DD, and depressive symptomatology were collected at baseline, at end-of-treatment and at one-, two-, three-, and six-month follow-ups.

RESULTS

CM for smoking cessation reduces DD rates (p = .0094). Smoking abstinence (p = .0024) and reduction in depressive symptoms (p = .0437) were associated with decreases in DD rates in long-term follow-up.

CONCLUSIONS

CM interventions for smoking cessation, smoking abstinence, and the improvement of depression contribute to reductions in DD over time.

A brief review of choice bundling: A strategy to reduce delay discounting and bolster self-control

Choice bundling is a behavioral economic strategy designed to reduce excessive delay discounting and bolster self-control. Choice bundling entails aggregating a series of individual, identical intertemporal decisions (e.g., should I smoke today?) into a single choice (e.g., should I smoke this month?). In this brief review, we succinctly summarize delay discounting and how it has been linked to lapses in self-control, using substance use as an exemplar. Next, we describe how choice bundling may theoretically work to counter excess discounting rates. Finally, we review the extant empirical research on choice bundling and offer recommendations for future research.

Some t-tests for N-of-1 trials with serial correlation

N-of-1 trials allow inference between two treatments given to a single individual. Most often, clinical investigators analyze an individual's N-of-1 trial data with usual t-tests or simple nonparametric methods. These simple methods do not account for serial correlation in repeated observations coming from the individual. Existing methods accounting for serial correlation require simulation, multiple N-of-1 trials, or both. Here, we develop t-tests that account for serial correlation in a single individual. The development includes effect size and precision calculations, both of which are useful for study planning. We then use Monte Carlo simulation to evaluate statistical properties of these serial t-tests, namely, Type I and II errors, and confidence interval widths, and compare these statistical properties to those of analogous usual t-test. The serial t-tests clearly outperform the usual t-tests commonly used in reporting N-of-1 results. Examples from N-of-1 clinical trials in fibromyalgia patients and from a behavioral health setting exhibit how accounting for serial correlation can change inferences. These t-tests are easily implemented and more appropriate than simple methods commonly used; however, caution is needed when analyzing only a few observations.

Neurocognitive Dysfunctions and Their Therapeutic Modulation in Patients With Methamphetamine Dependence: A Pilot Study

AIM

Methamphetamine (MA) abuse and dependence are increasing worldwide and are commonly associated with cognitive deficits. Some studies indicate that such impairments can improve if users become abstinent, but overall results remain inconclusive. Hence, we have performed a longitudinal case-control study investigating key surrogates for attention and impulsive decision-making before and after treatment.

METHODS

Thirty patients with MA dependence and 24 non-substance-abusing control participants were recruited. Groups were matched on age, sex and education. All subjects performed a baseline assessment to obtain neurocognitive measures of sustained attention and delay discounting. Patients subsequently participated in an MA-specific relapse prevention program including repeated monitoring of relapse status. After 3 months, participants of both groups were reevaluated for neurocognitive performance.

RESULTS

At baseline, MA patients showed a significantly higher number of omissions compared to controls, indicative of lower sustained attention. Interestingly, we observed a steep decrease of omissions in MA patients to control-group level post treatment. On the other hand, MA patients discounted delayed rewards significantly stronger than controls, indicating a more impulsive choice behavior both before and after treatment.

LIMITATION

The results should be interpreted with care because of the small sample and short follow-up period.

CONCLUSION

Our data support earlier findings on partial recovery of cognitive deficits in MA patients. They also strengthen the indication for recently recommended psychotherapeutic interventions and may provide a behavioral monitoring tool to inform treatment progress.

Behavioral trainings and manipulations to reduce delay discounting: A systematic review

In everyday decision-making, individuals make trade-offs between short-term and long-term benefits or costs. Depending on many factors, individuals may choose to wait for larger delayed reward, yet in other situations they may prefer the smaller, immediate reward. In addition to within-subject variation in the short-term versus long-term reward trade-off, there are also interindividual differences in delay discounting (DD), which have been shown to be quite stable. The extent to which individuals discount the value of delayed rewards turns out to be associated with important health and disorder-related outcomes: the more discounting, the more unhealthy or problematic choices. This has led to the hypothesis that DD can be conceptualized as trans-disease process. The current systematic review presents an overview of behavioral trainings and manipulations that have been developed to reduce DD in human participants aged 12 years or older. Manipulation studies mostly contain one session and measure DD directly after the manipulation. Training studies add a multiple session training component that is not per se related to DD, in between two DD task measurements. Ninety-eight studies (151 experiments) were identified that tested behavioral trainings and manipulations to decrease DD. Overall, results indicated that DD can be decreased, showing that DD is profoundly context dependent and changeable. Most promising avenues to pursue in future research seem to be acceptance-based/mindfulness-based trainings, and even more so manipulations involving a future orientation. Limitations and recommendations are discussed to identify the mechanistic processes that allow for changes in discount rate and behavior accordingly.

Delay Discounting in Impulsive Behavior

Abstract. Delay discounting (DD) is the process of devaluing results that happen in the future. With this review, we intend to identify specificities in the processes of DD in impulsive behavior. Studies were retrieved from multiple literature databases, through rigorous criteria (we included systematic reviews and empirical studies with adult human subjects), following the procedures of the Cochrane Collaboration initiative. Of the 174 documents obtained, 19 were considered eligible for inclusion and were retained for in-depth analysis. In addition, 13 studies from the manual search were included. Thus, a total of 32 studies were selected for review. The objectives/hypotheses, results, and the main conclusion(s) were extracted from each study. Results show that people with pronounced traits of impulsivity discount rewards more markedly, that is, they prefer immediate rewards, though of less value, or postponed losses, even though they worsen in the future. Taken together, the existing data suggest the importance of inserting DD as a tool for initial assessment in conjunction with measures of addiction and stress level, as well as the consideration of new therapies.

A Neurobehavioral Approach to Addiction: Implications for the Opioid Epidemic and the Psychology of Addiction

Two major questions about addictive behaviors need to be explained by any worthwhile neurobiological theory. First, why do people seek drugs in the first place? Second, why do some people who use drugs seem to eventually become unable to resist drug temptation and so become "addicted"? We will review the theories of addiction that address negative-reinforcement views of drug use (i.e., taking opioids to alleviate distress or withdrawal), positive-reinforcement views (i.e., taking drugs for euphoria), habit views (i.e., growth of automatic drug-use routines), incentive-sensitization views (i.e., growth of excessive "wanting" to take drugs as a result of dopamine-related sensitization), and cognitive-dysfunction views (i.e., impaired prefrontal top-down control), including those involving competing neurobehavioral decision systems (CNDS), and the role of the insula in modulating addictive drug craving. In the special case of opioids, particular attention is paid to whether their analgesic effects overlap with their reinforcing effects and whether the perceived low risk of taking legal medicinal opioids, which are often prescribed by a health professional, could play a role in the decision to use. Specifically, we will address the issue of predisposition or vulnerability to becoming addicted to drugs (i.e., the question of why some people who experiment with drugs develop an addiction, while others do not). Finally, we review attempts to develop novel therapeutic strategies and policy ideas that could help prevent opioid and other substance abuse.

The neurobiology of addiction

Substance and alcohol use disorders impose large health and economic burdens on individuals, families, communities, and society. Neither prevention nor treatment efforts are effective in all individuals. Results are often modest. Advances in neuroscience and addiction research have helped to describe the neurobiological changes that occur when a person transitions from recreational substance use to a substance use disorder or addiction. Understanding both the drivers and consequences of substance use in vulnerable populations, including those whose brains are still maturing, has revealed behavioral and biological characteristics that can increase risks of addiction. These findings are particularly timely, as law- and policymakers are tasked to reverse the ongoing opioid epidemic, as more states legalize marijuana, as new products including electronic cigarettes and newly designed abused substances enter the legal and illegal markets, and as "deaths of despair" from alcohol and drug misuse continue.

The role of the opioid system in decision making and cognitive control: A review

The opioid system regulates affective processing, including pain, pleasure, and reward. Restricting the role of this system to hedonic modulation may be an underestimation, however. Opioid receptors are distributed widely in the human brain, including the more "cognitive" regions in the frontal and parietal lobes. Nonhuman animal research points to opioid modulation of cognitive and decision-making processes. We review emerging evidence on whether acute opioid drug modulation in healthy humans can influence cognitive function, such as how we choose between actions of different values and how we control our behavior in the face of distracting information. Specifically, we review studies employing opioid agonists or antagonists together with experimental paradigms of reward-based decision making, impulsivity, executive functioning, attention, inhibition, and effort. Although this field is still in its infancy, the emerging picture suggests that the mu-opioid system can influence higher-level cognitive function via modulation of valuation, motivation, and control circuits dense in mu-opioid receptors, including orbitofrontal cortex, basal ganglia, amygdalae, anterior cingulate cortex, and prefrontal cortex. The framework that we put forward proposes that opioids influence decision making and cognitive control by increasing the subjective value of reward and reducing aversive arousal. We highlight potential mechanisms that might underlie the effects of mu-opioid signaling on decision making and cognitive control and provide directions for future research.

Effects of Acceptance and Commitment Therapy on Impulsive Decision-Making

This study examined the transdiagnostic effect of acceptance and commitment therapy (ACT) on impulsive decision-making in a community sample. A total of 40 adults were randomized to eight individual sessions of ACT or an inactive control. Participants completed pre-, mid-, and post-assessments for psychological symptoms; overall behavior change; valued living; delay discounting; psychological flexibility; and distress tolerance. Data were analyzed with multilevel modeling of growth curves. Significant interaction effects of time and condition were observed for psychological flexibility, distress tolerance, psychological symptoms, and the obstruction subscale of valued living. No significant interaction effect was found for two delay discounting tasks nor the progress subscale of valued living. The ACT condition had a significantly larger reduction of problem behavior at post-assessment. The results support use of ACT as a transdiagnostic treatment for impulsive behaviors. The lack of change in delay discounting contrasts previous research.

Threat appeals reduce impulsive decision making associated with texting while driving: A behavioral economic approach

The primary purpose of the present study was to examine the effectiveness of threat appeals in influencing impulsive decision making associated with texting while driving. The participants in the treatment group were exposed to a threatening message about the danger of texting while driving, whereas those in the control group were exposed to a non-threatening message. Following the exposure to either message, the participants completed a delay-discounting task that assessed the degree of impulsive decision making in a hypothetical texting-while-driving scenario. A comparison between the groups revealed that the threat appeals reduced the degree of impulsive decision making associated with texting while driving. In addition, the threat appeals led to greater anticipated regret from texting while driving, less favorable attitudes toward texting while driving, and decreased intentions to text while driving in the future in the treatment group. These results suggest that video-based threat appeals are promising intervention strategies for the public health challenge of texting while driving. Implications from the behavioral economic perspective are discussed.

Computational psychiatry of impulsivity and risk: how risk and time preferences interact in health and disease

Choice impulsivity is an important subcomponent of the broader construct of impulsivity and is a key feature of many psychiatric disorders. Choice impulsivity is typically quantified as temporal discounting, a well-documented phenomenon in which a reward's subjective value diminishes as the delay to its delivery is increased. However, an individual's proclivity to-or more commonly aversion to- risk can influence nearly all of the standard experimental tools available for measuring temporal discounting. Despite this interaction, risk preference is a behaviourally and neurobiologically distinct construct that relates to the economic notion of utility or subjective value. In this opinion piece, we discuss the mathematical relationship between risk preferences and time preferences, their neural implementation, and propose ways that research in psychiatry could, and perhaps should, aim to account for this relationship experimentally to better understand choice impulsivity and its clinical implications. This article is part of the theme issue 'Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications'.

Neuronal correlates of delay discounting in healthy subjects and its implication for addiction: an ALE meta-analysis study

BACKGROUND

Delay discounting (DD) describes the phenomenon of devaluing future rewards in favor of immediate rewards. Increased DD is a key behavioral marker of addiction, and has been suggested as a target for interventions to alleviate addiction symptoms (e.g., preference for immediate drug use over larger-and-later rewards, and relapses) in patients with substance use disorders (SUD).

OBJECTIVES

Performed a meta-analysis on neuroimaging results of DD regarding specific contrasts in healthy participants. Reviewed the results of existing patient studies in light of the meta-analyses results.

METHODS

We conducted activation likelihood estimation meta-analyses on DD neuroimaging studies (25 studies, n = 583; 354 males and 229 females) regarding six analytic strategies.

RESULTS

The meta-analyses revealed various subdivisions of the cortical-basal ganglia circuits that are associated with different aspects of DD in healthy subjects. By comparing the meta-analyses results and patients' studies regarding each contrast, we highlighted three brain regions that may underlie excessive DD in patients. Decreased left inferior frontal gyrus (IFG) activity was related to less preference for delayed choices; reduced ventral striatum (VS) activity was associated with impaired valuation processes; and declined anterior cingulate cortex (ACC)/medial prefrontal cortex (mPFC) activity was associated with alterations in processing difficult choices.

CONCLUSIONS

We propose that neuromodulation (e.g. deep brain simulation) or behavioral interventions (e.g. episodic future imagination) targeting these key brain regions (IFG, VS, ACC/mPFC) may be effective for improving DD function in patients with SUD, enhancing valuations of future rewards and helping to resist the temptation of immediate drug use.

Experimental reductions of delay discounting and impulsive choice: A systematic review and meta-analysis

Many behaviors posing significant risks to public health are characterized by repeated decisions to forego better long-term outcomes in the face of immediate temptations. Steeply discounting the value of delayed outcomes often underlies a pattern of impulsive choice. Steep delay discounting is correlated with addictions (e.g., substance abuse, obesity) and behaviors such as seatbelt use and risky sexual activity. As evidence accumulates suggesting steep delay discounting plays a causal role in these maladaptive behaviors, researchers have begun testing methods for reducing discounting. In this first systematic and comprehensive review of this literature, the findings of 92 articles employing different methodologies to reduce discounting are evaluated narratively and meta-analytically. Although most of the methods reviewed produced significant reductions in discounting, they varied in effect sizes. Most methods were ideal for influencing one-off choices (e.g., framing and priming manipulations), although other successful manipulations, such as episodic future thinking, could be incorporated into existing therapies designed to produce longer-lasting changes in decision-making. The largest and longest-lasting effects were produced by learning-based manipulations, although translational research is needed to determine the generality and clinical utility of these methods. Methodological shortcomings in the existing literature and suggestions for ameliorating these issues are discussed. This review reveals a variety of methods with translational potential, which, through continued refinement, may prove effective in reducing impulsive choice and its associated maladaptive decisions that negatively impact quality of life. (PsycINFO Database Record

The treasure of now and an uncertain future: Delay discounting and health behaviors among cancer survivors

BACKGROUND

The identification of new therapeutic targets to improve health behaviors among cancer survivors (CS) is likely to improve cancer treatment outcomes. Delay discounting (DD) rate is the degree to which one devalues rewards as a function of time to receipt. Lower DD rates (ie, prioritizing long-term over immediate rewards) are associated with healthier behaviors. CS often experience distress and thoughts of early mortality that can potentially shift priorities to the present and negatively impact DD rates, especially when newly diagnosed. Understanding relations between DD and health behaviors among CS will contribute to the examination of DD as a therapeutic target for improving health behaviors for CS.

METHOD

CS (n = 1001) were recruited from a web panel and administered a web-based questionnaire. Multivariate models examined relations among DD rate, years since diagnosis, and 10 health behavior indicators. We hypothesized that 1) higher DD rates would be associated with fewer years since diagnosis, and 2) lower DD rates would be associated with healthier behaviors, moderated by years since diagnosis.

RESULTS

In general, higher DD rates were associated with fewer years since diagnosis. Higher DD rates were associated with more alcohol consumption, cigarette smoking, other tobacco use, tanning booth use, and conversely, greater adherence to annual primary care visits. A significant interaction between DD rate and years since diagnosis was not found.

CONCLUSION

Lower DD rates are associated with several important healthy lifestyle behaviors. DD rate is a promising therapeutic target for new interventions to improve multiple health behaviors among CS.

The neurobiology of impulsivity and substance use disorders: implications for treatment

Impulsivity is strongly associated with substance use disorders (SUDs). Our review discusses impulsivity as an underlying vulnerability marker for SUDs, and treatment of co-occurring impulsivity in SUDs. Three factors should be considered for the complex relationship between impulsivity and a SUD: (1) the trait effect of impulsivity, centering on decreased cognitive and response inhibition, (2) the state effect resulting from either acute or chronic substance use on brain structure and function, and (3) the genetic and environmental factors (e.g., age and sex) may influence impulsive behavior associated with SUDs. Both subjective and objective measures are used to assess impulsivity. Together, treatment developments (pharmacological, behavioral, and neurophysiological) should consider these clinically relevant dimensions assessed by a variety of measures, which have implications for treatment matching in individuals with SUD. Despite its heterogeneity, impulsivity is a marker associated with SUDs and may be understood as an imbalance of bottom-up and top-down neural systems. Further investigation of these relationships may lead to more effective SUD treatments.

Alternate versions of a fixed-choice, delay-discounting assessment for repeated-measures designs

Delay discounting, reflected in the tendency to prefer immediate rewards over delayed rewards, is associated with most forms of problematic substance use. When assessed multiple times to examine within-individual changes, for example, following acute drug administration or an intervention, shifts in delay discounting simply because of repeated assessment is a concern, particularly when the assessment task is identical. This may be true for the Monetary Choice Questionnaire (MCQ), a widely used, fixed-item assessment of delay discounting. The present research examined possible within-individual difference/equivalence of MCQ indices at test/retest. This was contrasted with within-individual difference/equivalence when using an alternate version of the MCQ at retest, specifically developed to maintain the assessment structure and scoring of the original MCQ but with different choice items. Eighty-four participants completed delay discounting at test and retest with a 1-week interval; participants were randomized to complete the MCQ at both test and retest (MCQ/MCQ; n = 43) or complete the MCQ at test and an alternate version of the MCQ at retest (MCQ/MCQ-A; n = 41). Conventional hypothesis testing indicated no significant changes in delay discounting in the MCQ/MCQ condition or MCQ/MCQ-A condition. However, equivalence analysis, which is able to established whether scores are statistically equivalent, indicated that test/retest scores were not equivalent in some cases. Specifically, only 1 magnitude in the MCQ/MCQ condition was equivalent at test/retest, whereas 2 magnitudes in the MCQ/MCQ-A condition were equivalent at test/retest. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Impulsive choice and pre-exposure to delays: iv. effects of delay- and immediacy-exposure training relative to maturational changes in impulsivity

Impulsive choice describes preference for smaller, sooner rewards over larger, later rewards. Excessive delay discounting (i.e., rapid devaluation of delayed rewards) underlies some impulsive choices, and is observed in many maladaptive behaviors (e.g., substance abuse, gambling). Interventions designed to reduce delay discounting may provide therapeutic gains. One such intervention provides rats with extended training with delayed reinforcers. When compared to a group given extended training with immediate reinforcers, delay-exposed rats make significantly fewer impulsive choices. To what extent is this difference due to delay-exposure training shifting preference toward self-control or immediacy-exposure training (the putative control group) shifting preference toward impulsivity? The current study compared the effects of delay- and immediacy-exposure training to a no-training control group and evaluated within-subject changes in impulsive choice across 51 male Wistar rats. Delay-exposed rats made significantly fewer impulsive choices than immediacy-exposed and control rats. Between-group differences in impulsive choice were not observed in the latter two groups. While delay-exposed rats showed large, significant pre- to posttraining reductions in impulsive choice, immediacy-exposed and control rats showed small reductions in impulsive choice. These results suggest that extended training with delayed reinforcers reduces impulsive choice, and that extended training with immediate reinforcers does not increase impulsive choice.

Are intertemporal preferences contagious? Evidence from collaborative decision making

Prior research has provided substantial insight into individuals' intertemporal preferences (i.e., preferences about delayed rewards). In the present study, we instead investigated the preferences of small groups of individuals asked to express collective intertemporal decisions. The paradigm consisted of three phases. During the precollaboration and postcollaboration phases, participants completed an intertemporal decision task individually. During the collaboration phase, participants completed a similar task in small groups, reaching mutually-agreed-upon decisions. The results suggest that group preferences were systematically related to the mean of the group members' precollaboration preferences. In addition, collaborative decision making altered the group members' intertemporal preferences. Specifically, individuals' postcollaboration preferences converged toward the preferences of their respective groups. Furthermore, we found that individuals' postcollaboration preferences were independently related to both their precollaboration preferences and the preferences of the other group members, suggesting that individuals' postcollaboration preferences represented a revision of their precollaboration preferences based on the preferences observed in other group members. In Experiment 2, we demonstrated that similar patterns of results were found whether participants were making matching judgments or binary choices.

Maintained Physical Activity Induced Changes in Delay Discounting

Those who discount the subjective value of delayed rewards less steeply are more likely to engage in physical activity. There is limited research, however, showing whether physical activity can change rates of delay discounting. In a two-experiment series, treatment and maintenance effects of a novel, effort-paced physical activity intervention on delay discounting were evaluated with multiple baseline designs. Using a lap-based method, participants were instructed to exercise at individualized high and low effort levels and to track their own perceived effort. The results suggest that treatment-induced changes in discounting were maintained at follow-up for 13 of 16 participants. In Experiment 2, there were statistically significant group-level improvements in physical activity and delay discounting when comparing baseline with both treatment and maintenance phases. Percentage change in delay discounting was significantly correlated with session attendance and relative pace (min/mile) improvement over the course of the 7-week treatment. Implications for future research are discussed.

Delay discounting in opioid use disorder: Differences between heroin and prescription opioid users

BACKGROUND

Among those with opioid use disorder, heroin use is associated with poorer prognosis relative to use of prescription opioids alone. However, relatively little is known about distinguishing features between those who use heroin relative to those who use prescription opioids. In the present study we evaluated differences in delay discounting in those with opioid use disorder based on primary opioid of use. Delay discounting is associated with a range of negative outcomes and is an important therapeutic target in this population.

METHODS

Treatment-seeking adults with opioid dependence completed self-report measures including past-month opioid use and the Monetary Choice Questionnaire (Kirby and Marakovic, 1996; Kirby et al., 1999), a measure of delay discounting. Participants were divided into two groups based on whether they used any heroin in the past 30days or only prescription opioids, and delay discounting scores were compared between the groups. Group differences in sociodemographic or clinical variables were included in the analysis as covariates.

RESULTS

Results from a forward stepwise linear regression indicated that heroin use was associated with significantly higher delay discounting (B=-0.99, SE_B=0.34, t=-2.88, p=0.005), even when considering covariates.

CONCLUSIONS

Adults with opioid dependence who exclusively used prescription opioids had lower delay discounting relative to those who used heroin. This finding contributes further to the literature suggesting that heroin use is associated with greater clinical severity among those with opioid use disorder.

Prospective Analysis of Behavioral Economic Predictors of Stable Moderation Drinking Among Problem Drinkers Attempting Natural Recovery

BACKGROUND

As interventions have expanded beyond clinical treatment to include brief interventions for persons with less severe alcohol problems, predicting who can achieve stable moderation drinking has gained importance. Recent behavioral economic (BE) research on natural recovery has shown that active problem drinkers who allocate their monetary expenditures on alcohol and saving for the future over longer time horizons tend to have better subsequent recovery outcomes, including maintenance of stable moderation drinking. This study compared the predictive utility of this money-based "Alcohol-Savings Discretionary Expenditure" (ASDE) index with multiple BE analogue measures of behavioral impulsivity and self-control, which have seldom been investigated together, to predict outcomes of natural recovery attempts.

METHODS

Community-dwelling problem drinkers, enrolled shortly after stopping abusive drinking without treatment, were followed prospectively for up to a year (N = 175 [75.4% male], M age = 50.65 years). They completed baseline assessments of preresolution drinking practices and problems, analogue behavioral choice tasks (Delay Discounting, Melioration-Maximization, and Alcohol Purchase Tasks), and a Timeline Followback interview including expenditures on alcohol compared to voluntary savings (ASDE index) during the preresolution year.

RESULTS

Multinomial logistic regression models showed that, among the BE measures, only the ASDE index predicted stable moderation drinking compared to stable abstinence or unstable resolutions involving relapse. As hypothesized, stable moderation was associated with more balanced preresolution allocations to drinking and savings (odds ratio = 1.77, 95% confidence interval = 1.02 to 3.08, p < 0.05), suggesting it is associated with longer-term behavior regulation processes than abstinence.

CONCLUSIONS

The ASDE's unique predictive utility may rest on its comprehensive representation of contextual elements to support this patterning of behavioral allocation. Stable low-risk drinking, but not abstinence, requires such regulatory processes.

The Effects of Financial Education on Impulsive Decision Making

Delay discounting, as a behavioral measure of impulsive choice, is strongly related to substance abuse and other risky behaviors. Therefore, effective techniques that alter delay discounting are of great interest. We explored the ability of a semester long financial education course to change delay discounting. Participants were recruited from a financial education course (n = 237) and an abnormal psychology course (n = 80). Both groups completed a delay-discounting task for $100 during the first two weeks (Time 1) of the semester as well as during the last two weeks (Time 2) of the semester. Participants also completed a personality inventory and financial risk tolerance scale both times and a delay-discounting task for $1,000 during Time 2. Delay discounting decreased in the financial education group at the end of the semester whereas there was no change in delay discounting in the abnormal psychology group. Financial education may be an effective method for reducing delay discounting.

Initial examination of priming tasks to decrease delay discounting

Steep discounting of delayed rewards is linked with a variety of unhealthy behaviors that contribute to the major causes of preventable death and disease. Growing evidence suggests that decreases in delay discounting contribute to healthier preferences. This study sought to provide preliminary evidence for the viability of developing a brief priming task to reduce delay discounting in a large, diverse group of individuals. Participants (n=1,122) were randomized to one of three conditions: Future Focus (FF), Present Focus (PF), and Non-Temporal Focus (NTF) intended respectively to decrease, increase, or have no effect on delay discounting. Participants then completed the Monetary Choice Questionnaire, a brief assessment of delay discounting rate. Participants randomized to FF exhibited significantly lower discounting rates than those randomized to PF or NTF conditions. Race, Hispanic background, social self-monitoring, education, and cigarette smoking also accounted for a significant amount of variance in the discounting model. These findings provide support for the development of a brief priming intervention that might be examined in clinical or public health contexts to decrease discounting and support healthy choices.

Impulsive choice and pre-exposure to delays: III. Four-month test-retest outcomes in male wistar rats

Delay discounting describes the tendency for organisms to devalue outcomes because they are delayed. Robust, positive correlations exist between excessive delay discounting and many maladaptive behaviors (e.g., substance abuse, obesity). Several studies have demonstrated that delay discounting can be reduced and this may hold promise for improving treatment outcomes. One method of reducing delay discounting provides rats with extended training with delayed reinforcement (i.e., delay-exposure training) and this significantly reduces impulsive choices, relative to rats trained with an equal number of immediate-reinforcement sessions (i.e., immediate-exposure training). To evaluate the stability of this effect, 12 weanling male Wistar rats were randomly assigned to receive either delay-exposure or immediate-exposure training for 120 sessions. Impulsive choice was assessed using an increasing-delay procedure immediately following training and 120 days after completion of the initial assessment. Delay-exposed rats discounted delayed food rewards significantly less than immediate-exposed rats in the initial assessment and the reassessment conducted 120 days later. These results are encouraging as they suggest that the effects of delay-exposure training are robust to the passage of time and intervening experience.