(PS6-C74) Predictors of Opioid Craving Among Patients Admitted into a Residential Addiction Treatment Facility: Mindfulness and Reward Probability

Background: Drug misuse and overdose rates have risen amidst the COVID-19 pandemic. In 2020, 93,331 people died from drug overdoses (CDC, 2021), a 32% increase from the year prior and the largest figure recorded in a year. Nearly 70% of these deaths were due to opioid overdoses and reflect the persistence of the opioid epidemic. To combat the opioid use disorder (OUD) epidemic, continued efforts must focus on factors relevant to resilience and putative treatment mechanisms. Reward probability and mindfulness represent two such factors relevant to illicit drug misuse. Reward probability, measured with the Reward Probability Index (RPI; Carvalho et al., 2011), quantifies the availability of, and the ability to engage in, rewarding experiences that are not substance-based. Mindfulness, measured by the Cognitive-Affective Mindfulness Scale-Revised (CAMS-R, Feldman et al., 2007), involves the awareness of the present moment through non-judgmental, nonreactive lens. Mindfulness negatively associates with frequency and quantity of substance used and positively associated with abstinence rates (Li et al., 2017). While both factors associate with drug misuse more generally, further research is needed to understand the putative role that mindfulness and reward probability plays in OUD severity. As drug craving is a core symptom of SUD, the present study tested the hypotheses that dispositional mindfulness and reward probability would predict OUD patients’ craving above and beyond prior drug use.  

Methods: The current study reflects baseline eligibility assessments collected from participants (n = 34) admitted into a residential addiction treatment program, seeking enrollment into an ongoing clinical trial. All participants had an OUD diagnosis and completed an assessment battery, which included the Opioid Craving Scale (OCS; McHugh et al., 2021), CAMS-R, RPI, and Timeline Followback (TLFB; Sobell, 1992). A two-stage hierarchical multiple regression (HMR) was run to determine if the addition of RPI factors (reward probability, environmental suppression) and mindfulness improved the prediction of craving (OCS), beyond past 30-days drug use (TLFB).

 

Results: At stage one of the HMR, the past 30 days drug use significantly contributed to the regression model, F(1, 32) = 9.57, p = 0.004, accounting for 20.7% of the variation in craving. In stage two, the RPI reward probability factor and CAMS-R accounted for an additional 4.1% of the variation in craving (statistically insignificant; F(2, 30) = 1.86, p = 0.173). The model as a whole, however, was statistically significant, F(3, 30), p = 0.009, accounting for 24.7% of the variation in craving.

 

Discussion: Results add to the literature by evaluating two constructs (reward probability and mindfulness) that have only been previously evaluated independently.  While past 30 days use accounted for most of the model’s utility, the entire model significantly accounts for variation found, despite the small sample size, warranting further exploration into the predictive utility of reward probability and mindfulness. As Data collection is underway, more robust statistical analyses on a larger sample will further clarify the relationship between RPI, mindfulness, and OUD symptoms (i.e., craving).