Polysubstance use: Delay discounting in relationship to remission

BackgroundRemission from substance use disorders (SUDs) is typically conceptualized as an all-or-none phenomenon. Here, we present a novel construct: proportion of remission (PrR; i.e., the proportion of substances an individual is in remission from relative to lifetime SUD history), a continuous construct that may better capture progress towards recovery in polysubstance use. MethodsIndividuals (n= 2,417) in recovery from SUDs were recruited from International Quit and Recovery Registry (IQRR). Individuals completed a $1000 adjusting amount delay discounting (DD) task, and questions about current and past substance use over the past 12 months and lifetime. We estimated a series of single-level binomial regressions models using PrR as the independent variable and DD, maximum time in recovery, and maximum quit time as dependent variables. In addition, we performed a moderated mediation analysis to understand the relationship between PrR and recovery variables. ResultsWe report that DD, maximum time in recovery, and maximum quit time significantly predicted PrR in individuals with a history of polysubstance use. Further, we found that the relationship between maximum time in recovery and PrR was mediated by the maximum quit time across substances and differed by varying levels of DD. ConclusionResults suggest that longer quit time of any substance is related to improved recovery outcomes, particularly for individuals with low discounting rates. Together, interventions that focus on harm reduction and/or those that modulate DD may lead to improved clinical outcomes (including quit time and PrR) in individuals with a history of polysubstance use.