Restructuring Reward Mechanisms in Nicotine Addiction: A Pilot fMRI Study of Mindfulness-Oriented Recovery Enhancement for Cigarette Smokers

Abstract

The primary goal of this pilot feasibility study was to examine the effects of Mindfulness-Oriented Recovery Enhancement (MORE), a behavioral treatment grounded in dual-process models derived from cognitive science, on frontostriatal reward processes among cigarette smokers. Healthy adult (N = 13; mean (SD) age 49 ± 12.2) smokers provided informed consent to participate in a 10-week study testing MORE versus a comparison group (CG). All participants underwent two fMRI scans: pre-tx and after 8-weeks of MORE. Emotion regulation (ER), smoking cue reactivity (CR), and resting-state functional connectivity (rsFC) were assessed at each fMRI visit; smoking and mood were assessed throughout. As compared to the CG, MORE significantly reduced smoking (d = 2.06) and increased positive affect (d = 2.02). MORE participants evidenced decreased CR-BOLD response in ventral striatum (VS; d = 1.57) and ventral prefrontal cortex (vPFC; d = 1.7) and increased positive ER-BOLD in VS (d_VS = 2.13) and vPFC (d_vmPFC = 2.66). Importantly, ER was correlated with smoking reduction (r's = .68 to .91) and increased positive affect (r's = .52 to .61). These findings provide preliminary evidence that MORE may facilitate the restructuring of reward processes and play a role in treating the pathophysiology of nicotine addiction.

Figure 1

fMRI contrast of the group × time interaction on positive ER-BOLD response. A significant group (MORE, control) × time (Pre, Post) interaction was found in left ventral striatum (VS: −9, 14, −12; F(1,22) = 12.4, d = 2.13) and right vmPFC (9, 26, −16; F's(1,22) = 19.4, d = 2.66, K_e = 1648) (p_voxel < 0.05, α = .05, Monte Carlo). Parameter estimates from the model indicate a relative increase in BOLD response from baseline to 8 weeks post-MORE relative to the control group, who evidenced a decrease in BOLD response.

Figure 2

fMRI contrast of the group × time interaction on drug CR-BOLD response. A significant group (MORE, control) × time (Pre, Post) interaction in left ventral striatum (VS: −14, 16, −15) and right vmPFC (10, 20, −10). F's(1,22) = 6.7 to 7.9 d's = 1.57 to 1.7; K_e = 765, (p_voxel < 0.05, α = .05, Monte Carlo). Parameter estimates from the model indicate a relative decrease in BOLD response from baseline to 8 weeks post-MORE relative to the control group, who evidenced an increase in BOLD response.

Figure 3

Group (MORE, control) × time (Pre, Post) interaction in right rostral ACC (rACC)-OFC (x = 26, y = 46, z = 12) resting-state functional connectivity, F(1,22) = 19.8, d = 2.69, K_e = 1330 (p_voxel < 0.05, α = .05, Monte Carlo). The rACC seed was defined by a conjunction mask from the functional ROI clusters from the significant interaction revealed in the positive ER & CR model. Among smokers in the MORE condition, rsFC between rACC and OFC strengthened from baseline to 8 weeks post-MORE, whereas the control group evidenced weaker rsFC between these regions.