Adaptation of the Monetary Choice Questionnaire to accommodate extreme monetary discounting in cocaine users

Relationship Between Delay Discounting and Clinical Diabetes Outcomes: A Systematic Review

OBJECTIVE

To evaluate the evidence on the relationship between delay discounting and clinical diabetes outcomes, identify current measures, and recommend areas for future work.

METHODS

A reproducible search using OVID Medline, PsycINFO, PubMed, Science Direct, and Scopus was conducted. Articles published from database creation up to March 2024 were searched. Medical Subject Heading (MeSH) terms and keywords representing delay discounting and diabetes were used. Outcomes included hemoglobin A1c (HbA1c), LDL, body mass index (BMI), blood pressure, quality of life (QOL), psychosocial factors, self-care behaviors, and diabetes complications.

RESULTS

A total of 15 articles met the inclusion criteria and were included for final synthesis. Overall, 14 studies included in this review found a significant relationship between delay discounting and diabetes-related outcomes, such that higher delay discounting is significantly related to worse diabetes outcomes for HbA1c, self-care behaviors, BMI, stress, and quality of life across self-reported measures of delay discounting and delay discounting tasks.

CONCLUSIONS

Evidence supports the relationship between delay discounting and diabetes-related outcomes and self-care behaviors across measures of delay discounting and type of diabetes. To understand delay discounting as a mechanism driving diabetes outcomes and to develop targeted interventions, additional work using a multidisciplinary approach is needed to validate the construct, identify pathways, and refine intervention approaches that can be tested to improve population health.

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.

Why now and not later? An exploration into the neurocognitive correlates of delay discounting in bipolar disorder

Increased delay discounting is evident in bipolar disorder, though there is minimal research on the factors that impact delay discounting in this population. We evaluated neurocognitive correlates of delay discounting among relatively euthymic participants with bipolar disorder (N = 76) with (n = 31) and without (n = 45) past-year substance use disorders. There were no significant differences in the mean delay discounting value between the bipolar disorder group and the comorbid bipolar disorder and past-year substance use disorders group (p = .082, Cohen's d = 0.41). Using multiple regression, we evaluated the most important predictors of the delay discounting value. Impairments in executive functioning (per number of categories completed on the Wisconsin Card Sorting Test) and visuospatial construction (per the Rey-Osterrieth Complex Figure Test Copy Raw Score), as well as decreased years of education (all ps < .05), offered the best neurocognitive characterization of increased delay discounting in this sample.

Effects of substance use on monetary delay discounting among people who use stimulants with and without HIV: An ecological momentary assessment study

Exploration of the real-time relationship between substance use and delay discounting may reveal potential mechanisms driving high-risk behaviors. We conducted an ecological momentary assessment (EMA) study to investigate the effects of substance use on delay discounting in a sample of people who use stimulants (HIV+: 30; HIV-: 34). Participants completed multiple EMAs throughout the day for 28 days. The EMAs collected data on delay discounting and substance use (time since last substance use and level of intoxication). Delay discounting was assessed using a brief Monetary Choice Questionnaire (MCQ). Analyses were conducted using linear mixed effects modeling. Most participants (99.1%) used cocaine as their primary stimulant. Among participants without HIV, MCQ score remained relatively stable during the first 2 hr after stimulant use, followed by an increase during 2-6 hr (p < .05), before decreasing again. For alcohol and marijuana, the MCQ score was stable during the first 4 hr after use, with a sharp increase at 4-6 hr (p < .05), before decreasing again. Among participants with HIV, there were no changes in MCQ score as a function of time since recent substance use. These findings provide evidence of a plausible connection between delay discounting and acute withdrawal that may have relevance for risky behaviors. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Brain multimodal co-alterations related to delay discounting: a multimodal MRI fusion analysis in persons with and without cocaine use disorder

BACKGROUND

Delay discounting has been proposed as a behavioral marker of substance use disorders. Innovative analytic approaches that integrate information from multiple neuroimaging modalities can provide new insights into the complex effects of drug use on the brain. This study implemented a supervised multimodal fusion approach to reveal neural networks associated with delay discounting that distinguish persons with and without cocaine use disorder (CUD).

METHODS

Adults with (n = 35) and without (n = 37) CUD completed a magnetic resonance imaging (MRI) scan to acquire high-resolution anatomical, resting-state functional, and diffusion-weighted images. Pre-computed features from each data modality included whole-brain voxel-wise maps for gray matter volume, fractional anisotropy, and regional homogeneity, respectively. With delay discounting as the reference, multimodal canonical component analysis plus joint independent component analysis was used to identify co-alterations in brain structure and function.

RESULTS

The sample was 58% male and 78% African-American. As expected, participants with CUD had higher delay discounting compared to those without CUD. One joint component was identified that correlated with delay discounting across all modalities, involving regions in the thalamus, dorsal striatum, frontopolar cortex, occipital lobe, and corpus callosum. The components were negatively correlated with delay discounting, such that weaker loadings were associated with higher discounting. The component loadings were lower in persons with CUD, meaning the component was expressed less strongly.

CONCLUSIONS

Our findings reveal structural and functional co-alterations linked to delay discounting, particularly in brain regions involved in reward salience, executive control, and visual attention and connecting white matter tracts. Importantly, these multimodal networks were weaker in persons with CUD, indicating less cognitive control that may contribute to impulsive behaviors.

Likes and impulsivity: Investigating the relationship between actual smartphone use and delay discounting

The omnipresence of smartphones among adolescents and adults gives rise to the questions about excessive use and personality factors which are associated with heavier engagement with these devices. Previous studies have found behavioral similarities between smartphone use and maladaptive behaviors (e.g. drinking, gambling, drug abuse) in the context of intertemporal choice but mostly relied on participants’ self-reports regarding engagement with their phone. In this study, we collected actual usage data by smartphone application from 101 participants and assessed their tendency to discount future rewards, their reward responsiveness, self-control and consideration of future consequences. We found that smartphone screen time was correlated with choosing smaller immediate over larger delayed rewards and that usage of social media and gaming apps predicted delay discounting. Additionally, smartphone use was negatively correlated with self-control but not correlated with consideration of future consequences. Neither psychological variable could mediate the relationship between smartphone usage and delay discounting. Our findings provide further evidence that smartphone use and impulsive decision-making go hand in hand and that engagement with these devices needs to be critically examined by researchers to guide prudent behavior.

The delay-reward heuristic: What do people expect in intertemporal choice tasks?

Recent research has shown that risk and reward are positively correlated in many environments, and that people have internalized this association as a “risk-reward heuristic”: when making choices based on incomplete information, people infer probabilities from payoffs and vice-versa, and these inferences shape their decisions. We extend this work by examining people’s expectations about another fundamental trade-off — that between monetary reward and delay. In 2 experiments (total N = 670), we adapted a paradigm previously used to demonstrate the risk-reward heuristic. We presented participants with intertemporal choice tasks in which either the delayed reward or the length of the delay was obscured. Participants inferred larger rewards for longer stated delays, and longer delays for larger stated rewards; these inferences also predicted people’s willingness to take the delayed option. In exploratory analyses, we found that older participants inferred longer delays and smaller rewards than did younger ones. All of these results replicated in 2 large-scale pre-registered studies with participants from a different population (total N = 2138). Our results suggest that people expect intertemporal choice tasks to offer a trade-off between delay and reward, and differ in their expectations about this trade-off. This “delay-reward heuristic” offers a new perspective on existing models of intertemporal choice and provides new insights into unexplained and systematic individual differences in the willingness to delay gratification.

The delay-reward heuristic: What do people expect in intertemporal choice tasks?

Recent research has shown that risk and reward are positively correlated in many environments, and that people have internalized this association as a "risk-reward heuristic": when making choices based on incomplete information, people infer probabilities from payoffs and vice-versa, and these inferences shape their decisions. We extend this work by examining people's expectations about another fundamental trade-off-that between monetary reward and delay. In 2 experiments (total N = 670), we adapted a paradigm previously used to demonstrate the risk-reward heuristic. We presented participants with intertemporal choice tasks in which either the delayed reward or the length of the delay was obscured. Participants inferred larger rewards for longer stated delays, and longer delays for larger stated rewards; these inferences also predicted people's willingness to take the delayed option. In exploratory analyses, we found that older participants inferred longer delays and smaller rewards than did younger ones. All of these results replicated in 2 large-scale pre-registered studies with participants from a different population (total N = 2138). Our results suggest that people expect intertemporal choice tasks to offer a trade-off between delay and reward, and differ in their expectations about this trade-off. This "delay-reward heuristic" offers a new perspective on existing models of intertemporal choice and provides new insights into unexplained and systematic individual differences in the willingness to delay gratification.

Cocaine-related alterations in fronto-parietal gray matter volume correlate with trait and behavioral impulsivity

BACKGROUND

Chronic cocaine use is associated with structural brain abnormalities within prefrontal regions implicated in impulsivity. Despite high levels of impulsivity among persons who use cocaine, it is not known how reductions in gray matter volume (GMV) may relate to trait and behavioral measures of impulsivity.

METHODS

The sample included 39 active cocaine users (COC+) and 40 controls with no history of cocaine use (COC-). Participants had a brain scan on a 3 T MRI machine and completed out-of-scanner measures of trait impulsivity and delayed reward discounting. Whole-brain voxel-based morphometry was used to compare GMV between COC+ and COC-. Within regions that differed between groups, voxelwise correlations were conducted to examine the relationship between GMV and impulsivity.

RESULTS

In a whole-brain analysis, COC+ had broad reductions in GMV compared to COC- in bilateral frontal, parietal, occipital, and cerebellar regions. Lower GMV correlated with trait impulsivity in lateral prefrontal regions and with delayed reward discounting in medial prefrontal regions, while lower GMV correlated with both measures in the posterior parietal cortex. COC+ demonstrated significantly higher impulsivity than COC- on all measures, but the nature of the correlation with GMV was similar in both groups.

CONCLUSIONS

Reflecting the multi-faceted nature of impulsivity, these results show that trait and behavioral measures of impulsivity map differentially onto altered brain morphology. While the brain-behavior patterns were similar in COC+ and COC-, suggesting that impulsivity varies on a continuous spectrum, cocaine-related abnormalities in frontal-parietal brain systems may contribute to heightened impulsivity.

Reward and executive control network resting-state functional connectivity is associated with impulsivity during reward-based decision making for cocaine users

BACKGROUND

Cocaine addiction is related to impulsive decision making that is mediated by brain circuitry involved in reward processing and executive functions, such as cognitive control and attentional salience. Resting-state functional connectivity between reward and executive control circuitry is altered among cocaine users, with concomitant deficits in impulsivity and learning. Prior research has examined how select brain regions interact to influence impulsive decision making for drug users; however, research examining interactions between large-scale brain networks and impulsive behavior is limited.

METHODS

The current study compared reward and executive control network resting-state functional connectivity and its relationship to impulsive decision making between cocaine users (n = 37) and non-cocaine using control participants (n = 35). Participants completed computerized decision-making tasks and a separate resting-state functional magnetic resonance imaging scan. Data underwent independent component, dual regression, and linear regression moderation analyses.

RESULTS

Higher impulsivity on the Balloon Analogue Risk Task (BART) was associated with inverse resting-state connectivity between the left cognitive control and subgenual anterior cingulate extended reward networks for cocaine users, while the opposite was found for controls. Less impulsivity on the monetary choice questionnaire was associated with stronger positive resting-state connectivity between the attentional salience and striatal core reward networks for controls, while cocaine users showed no association between impulsivity and resting-state connectivity of these networks.

CONCLUSIONS

Cocaine users show aberrant associations between reward-executive control resting-state network coupling and impulsive decision making. The findings support the conclusion that an imbalance between reward and executive control circuitry contributes to impulsivity in drug use.

Cocaine dependence modulates the effect of HIV infection on brain activation during intertemporal decision making

BACKGROUND

Both HIV infection and chronic cocaine use alter the neural circuitry of decision making, but the interactive effects of these commonly comorbid conditions have not been adequately examined. This study tested how cocaine moderates HIV-related neural activation during an intertemporal decision-making task.

METHODS

The sample included 73 participants who differed on cocaine and HIV status (18 COC+/HIV+, 19 COC+/HIV-, 19 COC-/HIV+, 17 COC-/HIV-). Participants made choices between smaller, sooner and larger, delayed rewards while undergoing functional MRI. Choices varied in difficulty based on subjective value: hard (equivalently valued), easy (disparately valued), and control choices. A mixed-effects model controlling for education and smoking identified main and interactive effects of HIV and COC during hard relative to easy choices (difficulty contrast).

RESULTS

COC+ status was associated with lower activation in bilateral frontal gyri and right insular and posterior parietal cortices. HIV+ status was associated with higher activation in the visual cortex, but lower activation in bilateral prefrontal cortices and cerebellum and left posterior parietal cortex. COC moderated the effects of HIV in several clusters centered in the bilateral prefrontal cortices and cerebellum. In post-hoc analyses, there were significant effects of HIV status on activation for COC+, but not COC-, participants; interaction effects remained after controlling for polysubstance use.

CONCLUSION

Cocaine use may diminish the compensatory neural activation often seen among HIV+ samples during decision making. Our results highlight the importance of examining the neuropsychiatric effects of comorbid medical conditions to identify potential neural targets for cognitive remediation interventions.