Unsparing self-critique strengthens the field, but Bailey et al. overstate the 'problems with delay discounting'

Delay discounting of rewards and losses, alcohol use, and the influence of socioeconomic factors: A cross-sectional online study in frequent drinkers

BACKGROUND

Delay discounting describes the devaluation of future outcomes over time and is a popular behavioral construct in addiction research. Prior studies show modest yet consistent associations between problematic alcohol use and delayed reward discounting (DRD). However, the potential confounding influence of socioeconomic status (SES, e.g., income and education) is rarely addressed. In this study, we aimed to investigate the robustness of DRD as a predictor of alcohol use after controlling for socioeconomic and demographic variables. Additionally, we aimed to test the association between delayed loss discounting (DLD) and alcohol use in a sufficiently large sample.

METHODS

We collected data from 341 moderate-to-heavy-drinking participants (27.92 ± 21.12 g alcohol/day, 43.48 ± 11.90 years old, 49.9% female, UK residents) in a cross-sectional online study. DRD and DLD were measured using an intertemporal choice task. Questionnaires encompassed alcohol use (AUDIT, weekly alcohol consumption), education and income, subjective measures of past and present socioeconomic status, and impulsivity.

RESULTS

DRD, but not DLD, was significantly associated with AUDIT scores (r = 0.15) and weekly alcohol consumption (r = 0.12). DRD remained a significant yet weak predictor of AUDIT scores when controlling for education and income, but not when controlling for education and age.

CONCLUSIONS

We replicated a small but robust association between alcohol use and DRD, but not DLD. This association appeared to be confounded by education and age, but not by income. We conclude that socioeconomic and demographic variables should systematically be accounted for in future studies investigating DRD and alcohol use.

Delay discounting is associated with addiction and mental health measures while controlling for health behaviors and health barriers in a large US sample

Background

Excessive discounting of future rewards [delay discounting (DD)] may be a transdiagnostic process and treatment target underlying behavioral health outcomes, including trauma, depression, anxiety, and problematic substance use. However, multiple health behaviors and barriers are also related to these outcomes, including social media usage, adverse childhood experiences (ACEs), sleep quality, healthcare access, housing status, and exercise. To extend research examining DD as transdiagnostic process, we recruited a large, heterogenous sample to examine the association between DD, problematic substance use, and mental health outcomes while controlling for certain health behaviors and health barriers.

Method

In a cross-sectional online survey of 3992 US residents, we administered validated measures of PTSD, depression, anxiety, and problematic alcohol, stimulant, and opioid use. Using linear or ordinal logistic models, scores for each outcome were regressed onto DD while controlling for demographics, health behaviors, and health barriers.

Results

Including only DD and demographics, DD was associated with each outcome at low effect sizes (ƒ2 = .013, OR range = 1.08-1.16). Except for opioid ASSIST scores, these relationships held when controlling for social media usage, sleep, housing status, healthcare access, ACEs, physical exercise, and demographic variables (ƒ2 = .002, OR range = 1.03-1.12), increasing confidence that DD concurrently and directly relates to four of these five clinical outcomes.

Discussion

These findings support the conceptualization of DD as a transdiagnostic process underlying certain psychopathologies and suggest targeting DD in co-occurring substance use disorder and/or mental health treatments may result in clinically significant outcomes.

Posttraumatic stress and delay discounting: a meta-analytic review

Delay discounting-the extent to which individuals show a preference for smaller immediate rewards over larger delayed rewards-has been proposed as a transdiagnostic neurocognitive process across mental health conditions, but its examination in relation to posttraumatic stress disorder (PTSD) is comparatively recent. To assess the aggregated evidence for elevated delay discounting in relation to posttraumatic stress, we conducted a meta-analysis on existing empirical literature. Bibliographic searches identified 209 candidate articles, of which 13 articles with 14 independent effect sizes were eligible for meta-analysis, reflecting a combined sample size of N = 6897. Individual study designs included case-control (e.g. examination of differences in delay discounting between individuals with and without PTSD) and continuous association studies (e.g. relationship between posttraumatic stress symptom severity and delay discounting). In a combined analysis of all studies, the overall relationship was a small but statistically significant positive association between posttraumatic stress and delay discounting (r = .135, p < .0001). The same relationship was statistically significant for continuous association studies (r = .092, p = .027) and case-control designs (r = .179, p < .001). Evidence of publication bias was minimal. The included studies were limited in that many did not concurrently incorporate other psychiatric conditions in the analyses, leaving the specificity of the relationship to posttraumatic stress less clear. Nonetheless, these findings are broadly consistent with previous meta-analyses of delayed reward discounting in relation to other mental health conditions and provide further evidence for the transdiagnostic utility of this construct.

Delay discounting and alcohol consumption correlate with dorsal anterior insula activation during choice in nontreatment-seeking heavy drinkers

BACKGROUND

The anterior insular cortex (AIC), a prominent salience network node, integrates interoceptive information and emotional states into decision making. While AIC activation during delay discounting (DD) in alcohol use disorder (AUD) has been previously reported, the associations between AIC activation, impulsive choice, alcohol consumption, and connectivity remain unknown. We therefore tested AIC brain responses during DD in heavy drinkers and their association with DD performance, alcohol drinking, and task-based connectivity.

METHODS

Twenty-nine heavy drinkers (12 females; mean (SD) age=31.5 ± 6.1 years; mean (SD)=40.8 ± 23.4 drinks/week) completed a DD task during functional MRI. Regions activated during DD decision making were tested for correlation with DD behavior and alcohol drinking. Psychophysiological interaction (PPI) models assessed the task-dependent functional connectivity (FC) of activation during choice.

RESULTS

Delay discounting choice activated bilateral anterior insular cortex, anterior cingulate cortex, and left precentral gyrus. Right dorsal (d) AIC activation during choice negatively correlated withdiscounting of delayed rewards and alcohol consumption. PPI analysis revealed FC of the right dAIC to both the anterior and posterior cingulate cortices-key nodes in the midline default mode network.

CONCLUSIONS

Greater dAIC involvement in intertemporal choice may confer more adaptive behavior (lower impulsivity and alcohol consumption). Moreover, salience network processes governing discounting may require midline default mode (precuneus/posterior cingulate cortex) recruitment. These findings supporta key adaptive role for right dAIC in decision making involving future rewards and risky drinking.