A pilot study linking reduced fronto-Striatal recruitment during reward processing to persistent bingeing following treatment for binge-eating disorder

Abstract

Objective: The primary purpose of this study was to examine neurobiological underpinnings of reward processing that may relate to treatment outcome for binge-eating disorder (BED).

Method: Prior to starting treatment, 19 obese persons seeking treatment for BED performed a monetary incentive delay task during functional magnetic resonance imaging (fMRI). Analyses examined how the neural correlates of reward processing related to binge-eating status after 4-months of treatment.

Results: Ten individuals continued to report binge-eating (BEpost-tx ) following treatment and 9 individuals did not (NBEpost-tx ). The groups did not differ in body mass index. The BEpost-tx group relative to the NBEpost-tx group showed diminished recruitment of the ventral striatum and the inferior frontal gyrus during the anticipatory phase of reward processing and reduced activity in the medial prefrontal cortex during the outcome phase of reward processing.

Discussion: These results link brain reward circuitry to treatment outcome in BED and suggest that specific brain regions underlying reward processing may represent important therapeutic targets in BED.

Keywords: binge eating; fMRI; reward; treatment outcome.

Figure 1

Group differences on the Monetary Incentive Delay Task in frontostriatal areas in obese individuals with binge eating disorder (BED) following treatment. Brain activation maps demonstrate differences in the A2 winning phase (A2W, associated with the anticipation of winning money), the A2 losing phase (A2L, associated with the anticipation of losing money), and the outcome (OC) winning phase (OCW, associated with the receipt of a monetary reward). Maps depict differences in BED participants who reported bingeing following treatment (n = 10) contrasted with BED participants who did not report bingeing following treatment (n = 9). All contrast maps are thresholded at an uncorrected level of p < .05 two-tailed and family-wise-error-corrected at p < .05. Blue color demonstrates areas where bingeing subjects show relatively less activation and red color indicates where bingeing participants show relatively greater activation. The right side of the brain is on the right. BE_post-tx = Binge Eating Post Treatment NBE_post-tx = No Binge Eating Post Treatment