Abstract
RATIONALE: Dysregulated reward processing is a hallmark feature of drug addiction; however, scant research has evaluated restructuring reward processing in the context of addiction treatment. OBJECTIVES: We examined effects of Mindfulness-Oriented Recovery Enhancement (MORE) on reward responsiveness (RR) and opioid cue-reactivity in a sample of chronic pain patients with opioid use problems. We previously reported that MORE decreased pain, opioid misuse, and craving relative to a social support control group (SG). Here, we examined whether these outcomes were linked to changes in RR in a subset of participants. METHODS: Participants were chronic pain patients (71 % women, age 46.6 ± 13.9) who received MORE (n = 20) or SG (n = 29). RR was measured before and after 8 weeks of treatment via heart rate (HR) and heart rate variability (HRV) responses during a dot probe task that included opioid-related, pain-related, and natural reward stimuli, as well as craving ratings. RESULTS: The MORE group, who reported decreased opioid misuse and opioid craving during treatment, evidenced less subjective opioid cue-reactivity, greater HR decelerations, and greater increases in HRV to all cues after treatment compared to the SG; HR and HRV effects were most pronounced for natural reward cues. Within the MORE group, HR deceleration to natural reward cues was correlated with increased subjective arousal to the cues, whereas HR deceleration to opioid cues was correlated with decreased subjective arousal. Effects of MORE on craving were mediated by enhanced RR. CONCLUSIONS: Results suggest that during treatment with MORE, cardiac-autonomic responsiveness to non-drug reward increases, while reactivity to opioid reward decreases. Studies are needed to discern whether changes in RR were a result or a determinant of reductions in opioid misuse and craving. RR may play a role in addiction treatment.