Stress and reward processing in bipolar disorder: a functional magnetic resonance imaging study
Stress and reward processing in bipolar disorder: a functional magnetic resonance imaging study
复制标题
DOI：
10.1111/bdi.12444
复制
发表时间：
2016-11-01
影响因子：
5.4
通讯作者：
Pizzagalli, Diego A.
中科院分区：
文献类型：
--
作者：
Berghorst, Lisa H.;Kumar, Poornima;Pizzagalli, Diego A.
目的：负面生活压力与双相情感障碍（BD）情绪发作之间的联系已经确立，但这种联系背后的过程尚不清楚。越来越多的证据表明，压力会对奖励处理和相关的神经生物学基质产生负面影响，这表明失调的奖励系统可能提供了部分解释。方法：13名身心健康或轻度抑郁双相障碍患者和15名对照者在无压力和压力（包括不良表现反馈和金钱扣减威胁的负面心理社会压力源）条件下接受功能磁共振成像，进行货币激励延迟（MID）任务。结果：在假设驱动的兴趣区域分析中，在奖励预期期间，杏仁核中出现了显著的组-条件相互作用。与对照组相比，当预期潜在奖励时，双相障碍受试者在无应激条件下的杏仁核过度激活，而在应激条件下的杏仁核活性降低。此外，与对照组相比，双相障碍患者的杏仁核体积明显更大。在控制结构差异后，应激对杏仁核功能的影响仍然存在，而在无应激条件下，各组不再存在差异。在奖励消费过程中，由于双相障碍参与者在压力下对奖励的反应增加了壳核的激活，壳核中出现了一种组-条件相互作用，但在对照组中则相反。结论：总的来说，研究结果强调了双相障碍患者在使用奖励预测线索进行适应性目标导向行为时可能存在的障碍，并结合了压力诱导的对奖励消费的超敏反应。讨论了潜在的临床意义。
Objectives: A link between negative life stress and the onset of mood episodes in bipolar disorder (BD) has been established, but processes underlying such a link remain unclear. Growing evidence suggests that stress can negatively affect reward processing and related neurobiological substrates, indicating that a dysregulated reward system may provide a partial explanation. The aim of this study was to test the impact of stress on reward-related neural functioning in BD.Methods: Thirteen euthymic or mildly depressed individuals with BD and 15 controls performed a Monetary Incentive Delay (MID) task while undergoing functional magnetic resonance imaging during no-stress and stress (negative psychosocial stressor involving poor performance feedback and threat of monetary deductions) conditions.Results: In hypothesis-driven region-of-interest analyses, a significant group-by-condition interaction emerged in the amygdala during reward anticipation. Relative to controls, while anticipating a potential reward, subjects with BD were characterized by amygdalar hyperactivation in the no-stress condition but hypoactivation during stress. Moreover, relative to controls, subjects with BD had significantly larger amygdala volumes. After controlling for structural differences, the effects of stress on amygdalar function remained, whereas groups no longer differed during the no-stress condition. During reward consumption, a group-by-condition interaction emerged in the putamen due to increased putamen activation in response to rewards in participants with BD during stress, but an opposite pattern in controls.Conclusions: Overall, findings highlight possible impairments in using reward-predicting cues to adaptively engage in goal-directed actions in BD, combined with stress-induced hypersensitivity to reward consumption. Potential clinical implications are discussed.