Department of Psychiatry, University Medical Center Utrecht, Utrecht, the Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands.
Department of Experimental Psychology, Utrecht University, Utrecht, the Netherlands.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2019 Nov;4(11):966-974. doi: 10.1016/j.bpsc.2019.06.014. Epub 2019 Jul 10.
Stress has a major impact on the onset and recurrence of mood episodes in bipolar disorder (BD), but the underlying mechanisms remain unknown. Previous studies have shown distinct time-dependent effects of stress on reward processing in healthy individuals. Impaired reward processing is a core characteristic of BD, and altered reward processing during recovery from stress could influence the development and course of bipolar disorder.
We investigated brain responses during reward processing 50 minutes after stress using functional magnetic resonance imaging in 40 healthy control subjects and 40 patients with euthymic BD assigned to either an acute stress test (Trier Social Stress Test) or a no-stress condition.
Acute stress increased cortisol levels in both healthy control subjects and patients with BD. Ventral striatal responses to reward outcome were increased in healthy control subjects during stress recovery but not in patients with BD. For anticipation, no differences were found between the groups following stress.
For the first time, we show altered reward processing in patients with BD during the recovery phase of stress. These data suggest reduced neural flexibility of hedonic signaling in response to environmental challenges. This may increase the susceptibility to stressful life events in the future and play a role in the development of further psychopathology in the longer term.
压力对双相情感障碍（BD）的发作和复发有重大影响，但潜在机制尚不清楚。先前的研究表明，压力对健康个体的奖励处理有明显的时变效应。奖励处理受损是 BD 的核心特征，应激恢复过程中奖励处理的改变可能会影响双相情感障碍的发展和病程。
我们使用功能磁共振成像技术，在 40 名健康对照者和 40 名处于缓解期的 BD 患者中进行了研究，这些患者被分配到急性应激测试（特里尔社会应激测试）或无应激条件下。在应激后 50 分钟，我们研究了奖励处理过程中的大脑反应。
急性应激增加了健康对照组和 BD 患者的皮质醇水平。在应激恢复期间，健康对照组的腹侧纹状体对奖励结果的反应增强，但 BD 患者没有。对于预期，应激后两组之间没有差异。
我们首次在 BD 患者的应激恢复阶段显示出改变的奖励处理。这些数据表明，对环境挑战的快感信号的神经灵活性降低。这可能会增加未来对生活压力事件的易感性，并在长期内对进一步的精神病理学发展起到一定作用。
