The fundamental questions left unanswered: response to commentary on the 'problems with delay discounting'

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.

Smoking Dependence, Time-Discounting, and Sustained Cessation Behavior: A Longitudinal Study of Predominantly Light Smokers

INTRODUCTION

This study aimed to assess whether two established psychosocial predictors of smoking abstinence, nicotine dependence and time-discounting, also apply to a population of predominantly cigarette light smokers, which is the dominant pattern of smoking in countries like Mexico. Relatively infrequent smoking is increasingly prevalent, yet still harmful, making it important to understand the predictors of cessation in this population.

AIMS AND METHODS

Mexican adult smokers recruited from an online consumer panel were surveyed every 4 months between November 2018 and July 2020. We considered respondents who reported a quit attempt in between surveys (n = 1288). Dependence was measured with a 10-item version of the Wisconsin Inventory of Smoking Dependence Motives (WISDM). Time-discounting was assessed with five branching questions about hypothetical reward scenarios. Logistic models regressed sustained quit attempts (≥30 days of abstinence) at time t + 1 on study variables at time t.

RESULTS

We found strong interitem reliability (α = 0.92) and intraindividual consistency of our brief WISDM (ρ = 0.68), but moderate intraindividual consistency of the time-discounting measure (ρ = 0.48). Forty-eight percent of the sample reported sustained quit attempts, and 79% were non-daily or light daily smokers (≤5 cigarettes per day). Smokers with higher WISDM-10 had lower odds of sustained quitting and this result remained when controlling for smoking frequency and the Heaviness of Smoking Index (adjusted odds ratio [AOR] = 0.768). Time-discounting was unassociated with sustained quitting.

CONCLUSIONS

Our findings suggest that a brief, 10-item multidimensional measure of dependence is useful for predicting sustained quitting in a context of relatively light smoking; time-discounting appears less relevant, although our results are not conclusive because of the low test-retest reliability of our measure.

IMPLICATIONS

Given the increase in non-daily and light daily cigarette smoking in many countries, including in Mexico, and the health risks this still poses, it is important to understand the predictors of cessation among relatively light smokers. The WISDM-10 multidimensional measure seems to be a good instrument to assess dependence and predict successful quitting in this population, and possibly more appropriate than physical dependence measures. As such, it could help design and target more suitable cessation treatments for non-daily and daily light cigarette smokers. While this study did not find time-discounting to be a relevant predictor of smoking abstinence, future studies should explore other measures.