Trichotillomania (hair pulling disorder) and skin picking disorder are common and often debilitating mental health conditions, grouped under the umbrella term of body focused repetitive behaviors (BFRBs). Although the pathophysiology of BFRBs is incompletely understood, reward processing dysfunction has been implicated in the etiology and sustention of these disorders. The purpose of this study was to probe reward processing in BFRBs. 159 adults (125 with a BFRB [83.2% (n = 104) female] and 34 healthy controls [73.5% (n = 25) female]) were recruited from the community for a multi-center between-group comparison using a functional imaging (fMRI) monetary reward task. Differences in brain activation during reward anticipation and punishment anticipation were compared between BFRB patients and controls, with stringent correction for multiple comparisons. All group level analyses controlled for age, sex and scanning site. Compared to controls, BFRB participants showed marked hyperactivation of the bilateral inferior frontal gyrus (pars opercularis and pars triangularis) compared to controls. In addition, BFRB participants exhibited increased activation in multiple areas during the anticipation of loss (right fusiform gyrus, parahippocampal gyrus, cerebellum, right inferior parietal lobule; left inferior frontal gyrus). There were no significant differences in the win-lose contrast between the two groups. These data indicate the existence of dysregulated reward circuitry in BFRBs. The identified pathophysiology of reward dysfunction may be useful to tailor future treatments.

拔毛癖（拔毛障碍）和抠皮障碍是常见且经常使人精神健康衰弱的疾病，属于以身体为中心的重复行为 (BFRB) 的总称。尽管 BFRB 的病理生理学尚不完全清楚，但奖励处理功能障碍与这些疾病的病因和持续存在有关。本研究的目的是探讨 BFRB 的奖励处理过程。从社区招募 159 名成年人（125 名 BFRB [83.2% (n = 104) 女性] 和 34 名健康对照 [73.5% (n = 25) 女性]），使用功能成像进行多中心组间比较（fMRI）金钱奖励任务。比较 BFRB 患者和对照组在奖赏预期和惩罚预期期间大脑激活的差异，并对多重比较进行严格校正。所有组级分析均控制年龄、性别和扫描部位。与对照组相比，BFRB 参与者的双侧额下回（岛盖部和三角部）表现出明显的过度激活。此外，BFRB 参与者在预期损失期间表现出多个区域的激活增加（右侧梭状回、海马旁回、小脑、右侧顶下小叶；左侧额下回）。两组之间的胜负对比没有显着差异。这些数据表明 BFRB 中存在失调的奖赏回路。已确定的奖赏功能障碍的病理生理学可能有助于调整未来的治疗方法。