Delay Discounting Mediates The Relationship Between Physical Activity And Quality Of Life In Substance Use

Individuals with Substance Use Disorders (SUD) usually present a short temporal view (i.e., the lack of ability to project themselves into the future), which often precludes maintaining abstinence. The temporal window can be indexed by delay discounting (DD; preference for smaller, sooner rewards over larger, delayed ones) and is part of the executive functions. DD is often high in individuals with SUD, which can reflect in drug-seeking behaviors to fulfill their need for immediate rewards. Thus, DD is a critical process to be targeted in this population during recovery. Physical activity (PA) has been shown to impact executive functions and decision-making processes positively. However, how these variables interact with the quality of life (QOL) of those individuals remains to be explored. PURPOSE: To examine whether PA is associated with DD and whether DD mediates the relationship between PA and domains of quality of life (social, environmental, physical, and psychological) in individuals in recovery from SUD. METHODS: Data were collected from 191 (123 women; 43.94 ± 12.49) registrants of the International Quit & Recovery Registry who reported being in recovery from SUD. Participants completed the Health Behaviors Questionnaire, a minute DD task, the World Health Organization Quality of Life-BREF questionnaire, as well as demographics and SUD questions. PA was computed by extracting the fitness domain from the Health Behaviors Questionnaire. Multivariate linear regression was used to test associations between PA with DD, and PA with each QOL domain. Based on model selection, covariates included age and remission status. Then, mediation analyses were conducted for the significant associations, where PA was the independent variable, DD was the mediator, and each QOL domain served as the dependent variables. RESULTS: PA was negatively associated with DD (p < .001) and positively with all four QOL domains (ps ≤ .014). DD mediated the relationship between PA and the psychological (p = .008), environmental (p < .001), physical (p = .002), and social (p = .002) domains of the QOL questionnaire. CONCLUSIONS: PA can be an important tool in the treatment of SUD, as it is associated with less impulsive choices (i.e. longer temporal view), which in turn contributes to improving the quality of life of those individuals.