Opioid craving does not incubate over time in inpatient or outpatient treatment studies: Is the preclinical incubation of craving model lost in translation?

Within addiction science, incubation of craving is an operational label used to describe time-dependent increases in drug seeking during periods of drug deprivation. The purpose of this systematic review was to describe the preclinical literature on incubation of craving and the clinical literature on craving measured over extended periods of abstinence to document this translational homology and factors impacting correspondence. Across the 44 preclinical studies that met inclusion criteria, 31 reported evidence of greater lever pressing, nose pokes, spout licks, or time spent in drug-paired compartments (i.e., drug seeking) relative to neutral compartments after longer periods of abstinence relative to shorter periods of abstinence, labelled as "incubation of craving." In contrast, no clinical studies (n = 20) identified an increase in opioid craving during longer abstinence periods. The lack of clinical evidence for increases in craving in clinical populations weakens the translational utility of operationalizing the time-dependent increase in drug-seeking behavior observed in preclinical models as models of incubation of "craving".

A systematic review and meta-analysis of test-retest reliability and stability of delay and probability discounting.

In this meta-analysis, we describe a benchmark value of delay and probability discounting reliability and stability that might be used to (a) evaluate the meaningfulness of clinically achieved changes in discounting and (b) support the role of discounting as a valid and enduring measure of intertemporal choice. We examined test-retest reliability, stability effect sizes (dz ; Cohen, 1992), and relevant moderators across 30 publications comprising 39 independent samples and 262 measures of discounting, identified via a systematic review of PsychInfo, PubMed, and Google Scholar databases. We calculated omnibus effect-size estimates and evaluated the role of proposed moderators using a robust variance estimation meta-regression method. The meta-regression output reflected modest test-retest reliability, r = .670, p < .001, 95% CI [.618, .716]. Discounting was most reliable when measured in the context of temporal constraints, in adult respondents, when using money as a medium, and when reassessed within 1 month. Testing also suggested acceptable stability via nonsignificant and small changes in effect magnitude over time, dz = 0.048, p = .31, 95% CI [-0.051, 0.146]. Clinicians and researchers seeking to measure discounting can consider the contexts when reliability is maximized for specific cases.

Does acute cannabidiol (CBD) use impair performance? A meta-analysis and comparison with placebo and delta-9-tetrahydrocannabinol (THC).

Cannabidiol (CBD) is widely used and believed to be non-intoxicating, lacking acute performance effects (e.g., non-impairing). However, a synthesis of data has not evaluated this. This meta-analysis synthesized data from controlled human laboratory studies that evaluated if acute CBD use impairs performance. Performance on objective and subjective measures of cognitive and psychomotor function were used as markers for potential performance changes and impairment. Studies were identified through systematic database searches. Adult clinical trials measuring acute CBD effects (within 0-8 h of administration) were included. The primary outcome was the peak mean difference in performance measures between CBD and placebo. A secondary analysis utilizing delta-9-tetrahydrocannabinol (Δ9-THC) as a positive control for comparison to CBD was completed. Pooled Hedges' g estimates were calculated using robust variance estimation (RVE) meta-regression. The omnibus RVE meta-analysis indicated a statistically significant, but small effect size (Hedge's g < 0.2) for impaired performance following acute CBD consumption compared to placebo (N = 16 trials, Hedges' g = 0.122, 95% CI: 0.023-0.221, p = 0.019). Measure type was a significant moderator with larger mean differences between CBD and placebo when subjective measures, specifically self-reported sedation, were used versus objective performance tasks (Hedges' gSubjective = 0.288 versus Hedges' gObjective = 0.048). Δ9-THC had a significantly greater magnitude of impairment compared to CBD (N = 8, Hedges' g = 0.416, 95% CI: 0.017-0.816, p = 0.043). In summary, acute CBD consumption was associated with a small increase in subjective ratings of sedation, but no difference from placebo was observed across multiple domains of objectively assessed cognitive or psychomotor performance. These findings suggest that acute CBD alone is unlikely to significantly impair daily functioning or workplace performance.

Effects of kratom on driving: Results from a cross-sectional survey, ecological momentary assessment, and pilot simulated driving Study.

OBJECTIVES: Despite widespread kratom use, there is a lack of knowledge regarding its effects on driving. We evaluated the self-reported driving behaviors of kratom consumers and assessed their simulated-driving performance after self-administering kratom products. METHODS: We present results from: 1) a remote, national study of US adults who regularly use kratom, and 2) an in-person substudy from which we re-recruited participants. In the national study (N = 357), participants completed a detailed survey and a 15-day ecological momentary assessment (EMA) that monitored naturalistic kratom use. For the remote study, outcomes were self-reported general and risky driving behaviors, perceived impairment, and driving confidence following kratom administration. For the in-person substudy, 10 adults consumed their typical kratom products and their driving performance on a high-fidelity driving simulator pre- and post-kratom administration was evaluated. RESULTS: Over 90% of participants surveyed self-reported driving under the influence of kratom. Most reported low rates of risky driving behavior and expressed high confidence in their driving ability after taking kratom. This was consistent with EMA findings: participants reported feeling confident in their driving ability and perceived little impairment within 15-180 min after using kratom. In the in-person substudy, there were no significant changes in simulated driving performance after taking kratom. CONCLUSIONS: Using kratom before driving appears routine, however, self-reported and simulated driving findings suggest kratom effects at self-selected doses among regular kratom consumers do not produce significant changes in subjective and objective measures of driving impairment. Research is needed to objectively characterize kratom's impact on driving in regular and infrequent consumers.

Designing and Validating a Novel Method for Assessing Delay Discounting Associated With Health Behaviors: Ecological Momentary Assessment Study.

BACKGROUND: Delay discounting quantifies an individual's preference for smaller, short-term rewards over larger, long-term rewards and represents a transdiagnostic factor associated with numerous adverse health outcomes. Rather than a fixed trait, delay discounting may vary over time and place, influenced by individual and contextual factors. Continuous, real-time measurement could inform adaptive interventions for various health conditions. OBJECTIVE: The goals of this paper are 2-fold. First, we present and validate a novel, short, ecological momentary assessment (EMA)-based delay discounting scale we developed. Second, we assess this tool's ability to reproduce known associations between delay discounting and health behaviors (ie, substance use and craving) using a convenience-based sample. METHODS: Participants (N=97) were adults (age range 18-71 years), recruited on social media. In phase 1, data were collected on participant sociodemographic characteristics, and delay discounting was evaluated via the traditional Monetary Choice Questionnaire (MCQ) and our novel method (ie, 7-item time-selection and 7-item monetary-selection scales). During phase 2 (approximately 6 months later), participants completed the MCQ, our novel delay discounting measures, and health outcomes questions. The correlations between our method and the traditional MCQ within and across phases were examined. For scale reduction, a random number of items were iteratively selected, and the correlation between the full and random scales was assessed. We then examined the association between our time- and monetary-selection scales assessed during phase 2 and the percentage of assessments that participants endorsed using or craving alcohol, tobacco, or cannabis. RESULTS: In total, 6 of the 7 individual time-selection items were highly correlated with the full scale (r>0.89). Both time-selection (r=0.71; P<.001) and monetary-selection (r=0.66; P<.001) delay discounting rates had high test-retest reliability across phases 1 and 2. Phase 1 MCQ delay discounting function highly correlated with phase 1 (r=0.76; P<.001) and phase 2 (r=0.45; P<.001) time-selection delay discounting scales. One or more randomly chosen time-selection items were highly correlated with the full scale (r>0.94). Greater delay discounting measured via the time-selection measure (adjusted mean difference=5.89, 95% CI 1.99-9.79), but not the monetary-selection scale (adjusted mean difference=-0.62, 95% CI -3.57 to 2.32), was associated with more past-hour tobacco use endorsement in follow-up surveys. CONCLUSIONS: This study evaluated a novel EMA-based scale's ability to validly and reliably assess delay discounting. By measuring delay discounting with fewer items and in situ via EMA in natural environments, researchers may be better able to identify individuals at risk for poor health outcomes.

Use of preexposure prophylaxis and condom purchasing decisions.

Preexposure prophylaxis (PrEP) prevents human immunodeficiency virus (HIV) but not other sexually transmitted infections (STIs). Men who have sex with men (MSM) who take PrEP tend to report reduced condom use, but little is known about the underlying mechanisms. For this study, MSM who take PrEP (i.e., PrEP experienced; n = 88) and MSM who do not (i.e., PrEP naïve; n = 113) completed an online study, including the condom purchase task (CoPT). The CoPT assesses decisions to purchase condoms across escalating prices (range: free-$55) for sex with different types of hypothetical partners: those least likely to have an STD (least STD) and those that participants most want to have sex with (most want sex with). When condoms were free, PrEP-experienced MSM had a lower rate of condom purchasing than did PrEP-naïve MSM. For both partner types, PrEP-experienced MSM reached a price break point (i.e., would not buy condoms) at a lower price than did PrEP-naïve pariticipants. For the most-want-sex-with partner at the price at which participants elected not to buy condoms, only 23% of PrEP-experienced MSM chose to abstain from sex when not purchasing condoms versus 53% among PrEP-naïve MSM. Similar patterns were observed for the least-STD partner. The results support the potential utility of the CoPT in identifying behavioral mechanisms related to condom use and PrEP.

Knowledge, Preference, and Adverse Effects of Xylazine Among Adults in Substance Use Treatment.

This cross-sectional study evaluates aspects of xylazine adulteration of opioids among individuals entering substance use disorder treatment.

A brief measure of non-drug reinforcement: Association with treatment outcomes during initial substance use recovery.

BACKGROUND: Translational research demonstrates that drug use is inversely associated with availability and engagement with meaningful non-drug reinforcers. Evaluation of non-drug reinforcement in treatment-receiving clinical populations is limited, likely owing to the time intensive nature of existing measures. This study explores the association of non-drug reinforcers with treatment outcomes using a novel, brief measure of past month non-drug reinforcement quantifying three elements: relative frequency, access, and enjoyability. METHODS: Respondents enrolled in substance use treatment (residential, intensive outpatient, and medically managed withdrawal) in clinics across the United States (N = 5481) completed standardized assessments of non-drug reinforcement and treatment outcomes (i.e., return to use and life satisfaction) one-month after treatment discharge. Non-drug reinforcement measures (availability, engagement, enjoyability) were used as predictors of return to use and life satisfaction using generalized linear models. RESULTS: Non-drug reinforcement indices were associated with return to use and life satisfaction in unadjusted models (e.g., 12.4 % versus 58.3 % return to use for those with the highest and lowest availability, respectively). Consistent results were observed in models adjusted for sociodemographic variables and risk factors (i.e., sleep disturbance, anhedonia, stress). Comparisons by drug class generally showed lower non-drug reinforcement among patients reporting heroin or methamphetamine as their primary drug. CONCLUSIONS: Results highlight the importance of non-drug reinforcement during the first month following treatment. Rapid measurement of non-drug reinforcement in stepped care settings may illuminate critical deficits in early stages of behavior change, identify those at greatest risk for return to use, and provide targets for treatment to improve recovery trajectories.

Age moderates the association of optimism on craving during substance use disorder treatment.

BACKGROUND: Optimism, characterized by a positive expectancy toward future outcomes, has garnered attention for its potential role in influencing well-being and may be a protective factor in substance use disorder (SUD) treatment. This study evaluated the relationship of optimism and craving among those in substance use disorder SUD treatment. METHODS: Drawing from a cohort of 4201 individuals in residential SUD treatment programs, this study used both cross-sectional and longitudinal assessment to examine tonic (steady-state) and cue-induced (phasic) cravings across individuals primarily using eight classes of substances. Previous research established that optimism increases during adulthood and peaks during an individual's 50s. This study sought to establish if the association between optimism and craving is moderated by age during the first week of treatment and if that relationship changes over the course of treatment both within and between-person. RESULTS: This study found a negative correlation between optimism and craving intensity. Elevated optimism scores correlated with substantially reduced levels of both tonic (ß = -0.31, p < 0.001) and cue-induced (ß = -0.29, p < 0.001) cravings. Age was a significant moderator of the relationship between optimism and craving such that as individuals age, the potency of optimism in mitigating cravings gradually attenuates (interaction for tonic craving: ß = 0.06, p < 0.001; interaction for cue-induced craving: ß = 0.05, p < 0.001). Reflected in the fact that in older individuals' cravings tended to converge toward lower or moderate levels, regardless of their optimism scores. CONCLUSIONS: By delineating the contemporaneous association between high optimism and lower cravings, the study suggests that interventions aimed at fostering optimism may represent an avenue to improve the effectiveness of SUD treatment, especially in emerging adults.

Careless responding in online studies is associated with alcohol use: A mega-analysis.

OBJECTIVE: The prevalence of research conducted online in the addiction field has increased rapidly over the past decade. However, little focus has been given to careless responding in these online studies, despite the issues it may cause for statistical inference and generalizability. Our aim was to examine whether alcohol use is associated with careless responses. METHOD: Raw data were requested from online studies examining alcohol use and related problems which also addressed careless responding. We obtained 13 data sets of 12,237 participants (Mage = 42.16, SD = 15.65, 50.5% female). The sample had an average Alcohol Use Disorders Identification Test (AUDIT) score of 10.88 (SD = 7.77). Predictors included demographic information (age, gender) and AUDIT total scores. The primary outcome was whether an individual was classed as a careless responder, for example, by failing an explicit attention check question. RESULTS: AUDIT total scores were associated with careless responding (OR = 1.07, 95% CI [1.06, 1.08], p < .001). Hazardous drinking or worse was associated with 2.21 greater odds (OR = 2.21, 95% CI [1.81, 2.71] of careless responding, whereas harmful drinking or worse was associated with 3.43 greater odds (OR = 3.43, 95% CI [2.83, 4.17]) and probable dependence was associated with 3.63 greater odds (OR = 3.63, 95% CI [2.95, 4.48]). CONCLUSIONS: Alcohol use and related problems are positively associated with careless responding in online research. Removal of individuals identified as careless responders may lead to issues of generalizability, and more care should be taken to identify and handle careless responder data. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Using behavioral economics to optimize safer undergraduate late-night transportation.

Many universities sponsor student-oriented transit services that could reduce alcohol-induced risks but only if services adequately anticipate and adapt to student needs. Human choice data offer an optimal foundation for planning and executing late-night transit services. In this simulated choice experiment, respondents opted to either (a) wait an escalating delay for a free university-sponsored "safe" option, (b) pay an escalating fee for an on-demand rideshare service, or (c) pick a free, immediately available "unsafe" option (e.g., ride with an alcohol-impaired driver). Behavioral-economic nonlinear models of averaged-choice data describe preference across arrangements. Best-fit metrics indicate adequate sensitivity to contextual factors (i.e., wait time, preceding late-night activity). At short delays, students preferred the free transit option. As delays extend beyond 30 min, most students preferred competing alternatives. These data depict a policy-relevant delay threshold to better safeguard undergraduate student safety.

Adverse childhood experiences and early initiation of substance use: A survival analysis.

OBJECTIVE: Early adversity, such as adverse childhood experiences (ACEs), is a risk factor for the development of substance use disorder (SUD). ACEs are associated with earlier initiation of substance use. This study examined the relationship between ACEs and age of initiation of substance use using survival analysis. It is hypothesized that individuals with higher ACEs will have an earlier age of initiation. METHOD: Participants were recruited from the University of Kentucky's Laboratory for Human Behavioral Pharmacology. Participants were 18 years or older, English speaking, and actively engaged in substance use. Participants were not in substance abuse treatment nor were they seeking treatment. ACE scores were calculated, and age of substance use initiation was recorded. A Cox proportional hazard model was used to examine the effect of ACE score on age of substance use initiation. RESULTS: A total of 107 participants completed the study. An average number of 2.3 ACEs (SD = 2.2) were endorsed with 24% of participants reporting 4 or more ACEs. Higher ACE scores were associated with cigarette smoking and non-medical prescription opioid use onset ( hazard ratio (HR) = 1.14, 95% CI=1.02-1.28, p = 0.02, and HR=1.19, 95% CI = 1.04-1.37, p = 0.01, respectively. CONCLUSIONS: A significant association was found between higher ACE scores and earlier initiation of cigarette and non-medical prescription opioid use, consistent with prior research. Primary prevention of ACEs, screening for ACEs during childhood, and interventions for ACEs if detected, may help to reduce the risk of substance use/SUD in adulthood.

Effect of nicotine expectancy and nicotine dose reduction on cigarette demand, withdrawal alleviation, and puff topography.

BACKGROUND: Current FDA plans include proposed nicotine reduction mandates by the end of 2023. Most research on reduced nicotine cigarettes has been dose-blinded, while a mandate would be known to the public. Few laboratory studies have examined specifically how low nicotine content labeling impacts behavioral response. The purpose of this within-subject, balanced-placebo, human laboratory study was to evaluate the main and interactive effects of nicotine dose expectancy and dose reduction on cigarette reinforcement, withdrawal alleviation, and puff topography. METHODS: Participants who smoke daily (N=21; 9 female) completed one practice and four experimental sessions in which expectancy (labeled "average" versus "very low" nicotine) and nicotine dose (0.80mg versus 0.03mg yield) were manipulated. Participants in acute withdrawal sampled experimental cigarettes followed by withdrawal alleviation and puff topography measures. Cigarette demand was measured using an incentivized purchase task. Analyses evaluated main and interactive effects of expectancy and nicotine dose. RESULTS: Nicotine dose manipulation produced expected physiological effects (e.g., heart rate increases) and both reduced nicotine dose and expectation manipulations reduced perceived nicotine content. Expectation of reduced nicotine alone or in combination with reduced nicotine dose did not alter demand, withdrawal alleviation, or topography. Effective withdrawal alleviation was observed in all conditions. CONCLUSIONS: These data inform nicotine regulation policy by suggesting limited compensatory harms caused by reduced nicotine expectations. The minimal acute effects of reduced nicotine expectancy or exposure on demand suggests that reduced nicotine standards are likely to generate their greatest public health benefit through the slowing of newly initiating cigarette smoking.

Double-Blind Comparison of the Two Hallucinogens Dextromethorphan and Psilocybin: Experience-Dependent and Enduring Psychological Effects in Healthy Volunteers.

Rationale: N-methyl-D-aspartate receptor-mediated dissociatives and serotonergic hallucinogens are being increasingly used in therapeutic interventions that involve nonordinary states of consciousness and may represent a unique mental health paradigm wherein pharmacologically induced experiences are conducive to psychological well-being. Objective: The aim of this study was to further understand how the phenomenological and health-promoting effects of high-dose dextromethorphan (DXM) compared to psilocybin in the same participants when administered under experimental conditions that are typical of therapeutic psychedelic trials. Methods: Single, acute oral doses of DXM (400 mg/70 kg), psilocybin (10, 20, 30 mg/70 kg), and inactive placebo were administered under double-blind and psychologically supportive conditions to 20 healthy participants with histories of hallucinogen use. Ratings of personal meaning, spiritual significance, psychological challenge, and psychological insight attributed to acute drug experiences were assessed 7 h (at session end) and 1 week after each drug administration. Persisting psychological effects were assessed 1 week after each drug administration. Results: High-dose DXM and psilocybin produced similar increases over placebo in ratings of drug experience that was predictive of psychological benefit at 1 week, even when expectancy effects were minimized. These effects tended to favor psilocybin in a dose-dependent manner and were limited by poor physical tolerability for DXM. Conclusions: This analysis suggests the utility of exploring clinical applications of dissociatives that occur within the supportive contexts that are characteristic of psychedelic research and that prioritize the optimization of psychologically valuable drug experiences. This study was registered with ClinicalTrials.gov (NCT02033707).

Bystander preference for naloxone products: a field experiment.

BACKGROUND: Bystander administration of naloxone is a critical strategy to mitigate opioid overdose mortality. To ensure bystanders' willingness to carry and administer naloxone in response to a suspected overdose, it is critical to select products for community distribution with the highest likelihood of being utilized. This study examines bystanders' preference for and willingness to administer three naloxone products approved by the FDA for bystander use and identify product features driving preference. METHODS: The population was a convenience sample of individuals who attended the Kentucky State Fair, August 18-28, 2022, in Louisville, Kentucky. Participants (n = 503) watched a standardized overdose education and naloxone training video, rated their willingness to administer each of three products (i.e., higher-dose nasal spray, lower-dose nasal spray, intramuscular injection), selected a product to take home, and rated factors affecting choice. RESULTS: After training, 44.4% chose the higher-dose nasal spray, 30.1% chose the intramuscular injection, and 25.5% chose the lower-dose nasal spray. Factors most influencing choice on a 10-point Likert scale were ease of use (9 [7-10]), naloxone dose (8 [5-10]), and product familiarity (5 [5-9]). CONCLUSIONS: Bystanders expressed high willingness to administer all studied formulations of naloxone products. Product choice preference varied as a function of product features. As the number and variety of available products continue to increase, continuous evaluation of formulation acceptability, in addition to including individuals with lived experience who are receiving and administering overdose reversal agents, is critical to support adoption and save lives.

Naturalistic psilocybin use is associated with persisting improvements in mental health and wellbeing: results from a prospective, longitudinal survey.

Introduction: The classic psychedelic psilocybin, found in some mushroom species, has received renewed interest in clinical research, showing potential mental health benefits in preliminary trials. Naturalistic use of psilocybin outside of research settings has increased in recent years, though data on the public health impact of such use remain limited. Methods: This prospective, longitudinal study comprised six sequential automated web-based surveys that collected data from adults planning to take psilocybin outside clinical research: at time of consent, 2 weeks before, the day before, 1-3 days after, 2-4 weeks after, and 2-3 months after psilocybin use. Results: A sample of 2,833 respondents completed all baseline assessments approximately 2 weeks before psilocybin use, 1,182 completed the 2-4 week post-use survey, and 657 completed the final follow-up survey 2-3 months after psilocybin use. Participants were primarily college-educated White men residing in the United States with a prior history of psychedelic use; mean age = 40 years. Participants primarily used dried psilocybin mushrooms (mean dose = 3.1 grams) for "self-exploration" purposes. Prospective longitudinal data collected before and after a planned psilocybin experience on average showed persisting reductions in anxiety, depression, and alcohol misuse, increased cognitive flexibility, emotion regulation, spiritual wellbeing, and extraversion, and reduced neuroticism and burnout after psilocybin use. However, a minority of participants (11% at 2-4 weeks and 7% at 2-3 months) reported persisting negative effects after psilocybin use (e.g., mood fluctuations, depressive symptoms). Discussion: Results from this study, the largest prospective survey of naturalistic psilocybin use to date, support the potential for psilocybin to produce lasting improvements in mental health symptoms and general wellbeing.

Factors Associated with High-Risk Substance Use in Persons Receiving Psychiatric Treatment for a Primary Trauma- and Stressor-Related Disorder Diagnosis.

OBJECTIVE: Although mental health disorders and high-risk substance use frequently co-occur, they are typically investigated independently. Clinical trials focused on treatment for individuals with trauma- and stressor-related disorders often exclude individuals with high-risk substance use. Little is also known about the role of gender in the relationship between trauma- and stressor-related disorders and high-risk substance use. We examined the relationship between trauma- and stressor-related disorders, high-risk substance use, and gender. METHODS: Using the Mental Health Client-Level Data dataset, we examined 15,772 adults receiving treatment in psychiatric hospitals in the United States from 2013 to 2019. RESULTS: A logistic regression model showed that for men, relative to women, having multiple mental health diagnoses and having a serious mental illness or serious emotional disturbance was associated with greater odds of high-risk substance use. CONCLUSIONS: This study underscores the value of comprehensive gender-centered treatment for people with trauma- and stressor-related disorders engaging in high-risk substance use.

Response-contingent cocaine increases the reinforcing effectiveness of social contact.

Epidemiological studies report a high concordance rate of drug use within groups, suggesting an interplay between drug reinforcement and social cohesion. Preclinical studies reveal that (a) contingent access to a social partner increases cocaine intake and (b) experimenter-delivered cocaine increases the reinforcing effects of social contact. The purpose of this study was to determine if response-contingent cocaine increases the reinforcing effectiveness of social contact. Male rats were implanted with intravenous catheters and trained on a fixed ratio (FR1) schedule for 30-s access to a social partner. The reinforcing effectiveness of social contact was then determined using a progressive ratio (PR) schedule. After the PR test, rats were divided into two groups in which each response on an FR1 schedule produced social access and either response-contingent cocaine (0.5 mg/kg/infusion) or saline. After 9 days, the reinforcing effectiveness of social contact in the absence of infusions was determined again on the PR schedule. The cocaine and saline reinforcers were then switched between groups and the latter procedures were repeated. Recent exposure to response-contingent cocaine increased the reinforcing effectiveness of social contact on the PR schedule. This effect was transient, and the reinforcing effectiveness of social contact returned to baseline levels once response-contingent cocaine was replaced with saline. These data indicate that recent exposure to response-contingent cocaine transiently increases the reinforcing effectiveness of social contact and suggest that cocaine use may strengthen social cohesion by increasing the reinforcing effects of social contact with other individuals. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The endowment effect and temporal discounting of drug and non-drug commodities.

OBJECTIVES: Despite a rich history of behavioral economic research on substance use there remains a need for further exploration of behavioral mechanisms that may underlie the etiology or persistence of substance use disorder. The purpose of this study was to measure the association between delay discounting and the endowment effect in people who smoke cigarettes, use cocaine, and controls, using online crowdsourcing. METHODS: Participants were categorized to a cocaine group (n = 36), cigarette group (n = 48), or control group (n = 47) based on recent reported drug use. Based on group, participants completed up to three delay discounting tasks (i.e., money, cigarettes and cocaine), an endowment effect task for multiple commodities, and other questionnaires. RESULTS: Participants in the cocaine and cigarette group demonstrated an increased rate in discounting for money compared to controls. Participants in the cocaine group had a less pronounced endowment effect for beer, compared to controls, as suggested by willingness to accept less to sell beer. A significant negative association was found between endowment ratios for non-drug commodities and delay discounting for cigarettes, but not monetary or cocaine delay discounting, indicating an inconsistent relationship between the two measures. CONCLUSIONS: These results support prior research demonstrating a relationship between cocaine and cigarette use and delay discounting and extend that work by measuring the association between delay discounting and the endowment effect. Future research should include both loss aversion and endowment effect tasks and compare their relationship with delay discounting among people that use drugs.