Using an Experimental Medicine Approach to Identify Novel Determinants of Addiction

Comparison of Emotional Processing Between Patients with Substance Use Disorder and Those with Dual Diagnosis: Relationship with Severity of Dependence and Use During Treatment

This study analyzed, in a Spanish sample, the differences in emotional processing in patients diagnosed with substance use disorder (SUD) and patients with a dual diagnosis (DD), and tested whether alterations in emotional regulation were related to the severity of dependence and consumption during treatment. A descriptive follow-up study was conducted with 88 adult outpatients (83% men) who were receiving treatment for alcohol and cocaine SUD. Of the sample, 43.2% presented dual diagnosis according to DSM-IV-TR criteria. Emotional processing was assessed with the IAPS, and dependence severity with the SDSS. Consumption was determined with self-reports and toxicological tests. Regression analyses revealed that the DD group had more difficulties in identifying the valence and arousal of the images than patients with SUD. Patients with DD presented more difficulty in identifying images in which valence was manipulated, but not in those in which arousal was manipulated. Cocaine use during treatment was associated with difficulties in identifying unpleasant (U = 734.0; p < .05) and arousing (U = 723.5; p < .05) images. Although these results are preliminary, findings suggest that impaired emotional processing is aggravated in dual patients, although it may be a common transdiagnostic factor in SUD and other comorbid mental disorders. Findings highlight the importance of evaluating emotional regulation to better understand its possible role in the maintenance of substance use.

The Phenotype of Recovery X: Associations between delay discounting, regulatory flexibility, and remission from substance use disorder

INTRODUCTION

Delay discounting (DD) and self-regulation are important predictors of substance use disorder (SUD) outcomes. Further, regulatory flexibility (RF; i.e., selecting, monitoring, and adapting coping techniques based on contextual demands) is related to psychological resilience. However, studies have yet to examine associations among DD, RF, and remission from SUDs among individuals in recovery.

METHODS

Individuals (N = 148) in SUD recovery completed the Context Sensitivity Index (CSI), the Flexible Regulation of Emotional Expression (FREE) Scale, and the Perceived Ability to Cope with Trauma (PACT) Scale to assess RF and, an $1000 hypothetical reward Adjusting Amount Delay Discounting Task. The study considered individuals to be in remission from SUD if they did not endorse any SUD DSM-5 symptom other than craving (except tobacco use disorder) in the past three months. The study team used t-tests to examine differences in RF and DD by remission status. Univariate linear regressions were used to examine the relationship between RF and DD. Finally, mediation models examined the dynamic relationship among DD, RF, and remission status.

RESULTS

Remitted individuals (n = 82) had significantly lower DD (i.e., greater preference for larger, later rewards) rates (p < .001) and higher context sensitivity (p < .001) and coping flexibility (p < .001). The study found significant negative associations between DD and context sensitivity (p = .008), coping flexibility (p = .002), and emotion regulation flexibility (p < .001). Finally, context sensitivity (p = .023) and coping flexibility (p = .009) mediated the relationship between DD and SUD remission.

CONCLUSIONS

Results suggest that individuals in recovery with broader temporal windows can better identify contextual demands and flexibly cope, contributing to improved SUD recovery outcomes.

Future thinking to decrease real-world drinking in alcohol use disorder: Repairing reinforcer pathology in a randomized proof-of-concept trial

Reinforcer Pathology theory proposes that expanding the temporal window of reinforcement (i.e., reducing delay discounting) using episodic future thinking (EFT) would decrease alcohol consumption. However, evidence of effectiveness in real-world settings is lacking. Using a randomized proof-of-concept field trial, the current study examined the effect of expanding the temporal window of reinforcement, using remotely delivered EFT, on decreasing real-world alcohol consumption among individuals with alcohol use disorder (AUD). Fifty-two individuals (9 females) aged 18-65 years who met the DSM-5 criteria for moderate or severe AUD and aimed to drink in moderation or abstain from drinking completed the study and were included in analysis. EFT significantly (p = .031) reduced alcohol consumption (mean change of consumption pre-post intervention = -2.18 drinks/day) compared to control episodic recent thinking (ERT; mean change of -0.52 drinks/day). Changes in discounting rates pre-post intervention significantly predicted changes in alcohol consumption (coef. = .424, 95% CI [.043-.813], p = .030) even after controlling for age, gender, race, income, education, marital status, and family history of addiction. Overall satisfaction across groups was rated as 3.92 on a 1 to 5-point scale, suggesting that the current remote approach is feasible and acceptable. The current findings were congruent with the theory, Reinforcer Pathology, that EFT expands the temporal window and decreases alcohol consumption, and the remote approach was considered feasible and acceptable. We believe the present study contributes new knowledge with tangible benefits for scientifically understanding and better defining novel interventions that may be clinically deployed to improve treatment outcomes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Loss aversion and risk for cigarette smoking and other substance use

BACKGROUND

Cigarette smoking is among the leading preventable causes of global morbidity and mortality. We aimed to determine whether individual differences in loss aversion, a bias in decision-making wherein losses are valued greater than gains, predicts smoking and other addiction risk.

METHODS

We recruited current daily cigarette smokers (n = 181; > 10 cigarettes per day) and never-smokers (n = 237; < 100 cigarettes lifetime) from the United States using Amazon Mechanical Turk. Groups were matched on gender, educational attainment, and age. All completed items related to current cigarette smoking, alcohol use, other drug use, sleep problems, and depressed mood, and task-based measures of loss aversion and delay discounting, a decision-making bias associated with cigarette smoking.

RESULTS

Smokers were less loss averse than never-smokers (F(1, 411) = 24.19, η² = 0.02, p < .0001) even after accounting for delay discounting (F(1, 410) = 20.53, η² = 0.02, p < .0001). Loss aversion was also a significant independent risk factor for alcohol (F(1, 410) = 21.47, η² = 0.02, p < .0001) and other drug use (F(1, 410) = 54.12, η² = 0.04, p < .0001), although not other behavioral-health conditions (i.e., sleep disturbance, depressed mood). Further analyses revealed that co-occurring low loss aversion and high delay discounting were independently associated with greater risk for all patterns of substance use.

CONCLUSIONS

Loss aversion was associated with current cigarette smoking and other substance use patterns independent of delay discounting. Loss aversion may warrant attention as a protective factor and potential target for preventive intervention for substance use and addiction.

Single case designs for early phase behavioral translational research in health psychology

OBJECTIVE

The biomedical research community has long recognized that much of the basic research being conducted, whether in the biological, behavioral or social sciences, is not readily translated into clinical and public health applications. This translational gap is due in part to challenges inherent in moving research findings from basic or discovery research to applied research that addresses clinical or public health problems. In the behavioral and social sciences, research designs typically used in the early phases of translational research are small, underpowered "pilot" studies that may lack sufficient statistical power to test the research question of interest. While this approach is discouraged, these studies are often employed to estimate effect sizes before embarking on a larger trial with adequate statistical power to test the research hypothesis. The goal of this paper is to provide an alternative approach to early phase studies using single case designs (SCDs).

METHOD

Review basic principles of SCDs; provide a series of hypothetical SCD replication experiments to illustrate (1) how data from SCDs can be analyzed to test the effects of an intervention on behavioral and biological outcomes and (2) how sample sizes can be derived for larger randomized controlled trials (RCTs) based on clinically meaningful effects from SCDs; and review feedback between SCDs and RCTs.

RESULTS

The paper illustrates the use of SCD reversal and multiple baseline designs for early phase translational research.

CONCLUSION

SCDs provide a flexible and efficient platform for the use of experimental methods in early phase translational research. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Reinforcer pathology's alternative reinforcer hypothesis: A preliminary examination

BACKGROUND AND OBJECTIVE

The novel theory of Reinforcer Pathology states that the temporal window of integration, measured by delay discounting (DD), determines the value of reinforcers. Based on the Reinforcer Pathology theory, the valuation of alternative reinforcers is positively associated with the length of the temporal window (negatively with rates of discounting). The objective of this article is to test the Reinforcer Pathology theory by reanalyzing data from a prior report (Carr & Epstein, 2018) in order to examine the association between the reinforcing value of alternative reinforcement and the length of the measured temporal window.

METHOD

Participants (N = 250) who completed an adjusting delay discounting task and the Pleasant Events Schedule (PES) were included in the study. PES provides a measurement of a reinforcement score (a cross-product of PES measures of frequency and pleasantness) for 45 noneating alternative activities. Analysis of Variance and Spearman product-moment correlations were completed.

RESULTS

Delay discounting was significantly positively correlated with sedentary reinforcement and significantly negatively correlated with cognitively enriching activities. A significant interaction was observed in the preference for between food and cognitive-enriching context as a function ln(k) in predicting the cognitive-enriching activity class. Nonsignificant relationships were also observed with the correlation of delay discounting to the reinforcement of social and physical activities.

CONCLUSIONS

These findings provide initial support for Reinforcer Pathology theory and indicate that the temporal window over which reinforcers are integrated may be a factor contributing to a preference for some healthy or unhealthy alternative reinforcers. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Reinforcer pathology in cocaine use disorder: Temporal window determines cocaine valuation

AIMS

The Experimental Medicine Approach offers a unique perspective to determine clinical behavior change by engaging a target underlying the cause of a disorder. The present work engaged a novel target of addiction, Reinforcer Pathology, in two studies to test changes in behavior among individuals with cocaine use disorder.

METHODS

In Study 1, n = 44 participants engaged the temporal window with episodic future thinking (EFT), a positive prospection exercise. Changes in temporal view and cocaine valuation were tested using delay discounting and behavioral economic demand, respectively. Additionally, a computational model assessed the relative reliance on the near- and far-sighted systems during EFT. In Study 2, n = 71 engaged the temporal window with a negatively-valenced hurricane scenario to test the opposite effects on window length and cocaine valuation.

RESULTS

Results demonstrated systematic and symmetrical engagement of the behavioral target. Study 1 robustly replicated previous work, wherein EFT lengthened the temporal window and decreased cocaine valuation. Moreover, EFT increased the weighting of the modeled far-sighted system, increasing the relative impact of long-term discounting decisions. Study 2 produced opposite outcomes, shortened temporal window and increased cocaine valuation.

CONCLUSIONS

This approximately equal and opposite reaction to the manipulations supports reinforcer pathology theory and implicates the temporal window over which rewards are valued as a target to be pushed and pulled to produce clinically meaningful behavior change. Using the Experimental Medicine Approach as a guide, future work should identify new potential interventions to engage reinforcer pathology and use the clinically relevant outcomes as a litmus test for mechanism.

Episodic future thinking reduces chronic pain severity: A proof of concept study

BACKGROUND

Chronic pain is a major public health challenge in the United States and around the world. Current treatments including opioid analgesics and cognitive behavioral therapy possess harmful side effects or limited efficacy, respectively. Chronic pain is associated with a variety of unhealthy behaviors including opioid misuse. Moreover, individuals who suffer from chronic pain exhibit excessive discounting of delayed rewards, suggesting a constricted temporal window of valuation. Reductions in the excessive discounting of delayed rewards has been achieved with Episodic Future Thinking (EFT; vividly imagining realistic future events). EFT has also been associated with reductions in a variety of unhealthy behaviors. In this study, the effects of EFT on delay discounting and levels of pain were investigated in individuals reporting chronic pain.

METHODS

Individuals reporting chronic pain (N = 250; 42.4 % female) were recruited through the Amazon Mechanical Turk platform. Measures of delay discounting and pain were collected at baseline and again after randomization to EFT (N = 128) or Control Episodic Thinking (CET) (N = 122).

RESULTS

EFT significantly reduced delay discounting relative to baseline (p < 0.001) and EFT reduced pain scores in a baseline dependent manner (p = 0.001) when compared to CET; that is, those with the greatest reports of pain experienced the greatest reduction. Furthermore the reduction in delay discounting fully mediated the reduction in pain.

CONCLUSIONS

These findings suggest that Episodic Future Thinking, by widening the temporal window, may reduce pain in those reporting chronic pain and therefore represents a potential novel therapeutic.

Targeting cognitive and emotional regulatory skills for smoking prevention in low-SES youth: A randomized trial of mindfulness and working memory interventions

Research to date provides striking evidence that youth from low socio-economic status (SES) households are at an increased risk for smoking. Converging evidence from developmental studies, psychopathology studies, intervention studies, and basic research on self-control abilities have identified working memory and distress tolerance as potential crucial modifiable risk factors to prevent smoking onset in this cohort. To confirm the value of these mechanistic targets, this randomized trial was designed to evaluate the influence of working memory and distress tolerance interventions on risk of smoking initiation. Recruiting primarily from low-income community afternoon programs, we randomized 93 adolescents to one of three intervention conditions, all of which were a prelude to a smoking-prevention informational intervention: (1) a working memory intervention, (2) a mindfulness training intervention to target distress tolerance, and (3) a wellness-focused control condition. Despite a number of adherence efforts, engagement in treatment was limited, and under these conditions no significant evidence was found either for differential efficacy for smoking prevention or for intervention effects on mechanistic targets. However, working memory capacity and distress tolerance were found to be negatively related to smoking propensity. As such, our mechanistic targets-working memory and distress tolerance--may well be processes undergirding smoking, despite the fact that our interventions did not adequately engage these targets.

A Reinforcer Pathology perspective on relapse

The Reinforcer Pathology theory proposes conditions under which drugs emerge as excessively preferred reinforcers compared to other available reinforcers among drug users. The theory highlights 2 key variables as important determinants of drug preference: (a) excessive preference for immediate rewards (high discounting of future rewards); and (b) excessive valuation for addictive reinforcers (e.g., drugs). Two iterations of the Reinforcer Pathology theory exist with the latest iteration (i.e., Reinforcer Pathology 2.0) specifying that the temporal window of reinforcer integration (measured by delay discounting) is a determinant of reinforcer value. The 2 iterations of the Reinforcer Pathology theory are described. A novel insight and understanding of abstinence and relapse from a Reinforcer Pathology perspective, limitations, and future directions are discussed. The Reinforcer Pathology theory continues the long-standing efforts to scientifically understand and better define novel concepts and methods to further translational research and improve treatment outcomes. Exploring the complementary relation between the Reinforcer Pathology perspective and other current approaches could have a valuable effect.