Recent research has emphasized rumination as an important maintaining factor in various mental disorders. However, operationalization and therefore induction of rumination in experimental settings poses a major challenge in terms of ecological validity. As stress seems to play a key role in everyday situations eliciting rumination, we conducted two stress paradigms while assessing behavioral and neurophysiological measures.

Aiming to replicate previous findings on induced rumination by means of the Trier Social Stress Test (TSST) and comparing them to physiological (pain) stress, a clinical sample of patients with Major Depressive Disorder (MDD; n = 22) and healthy controls (HC; n = 23) was recruited. Cortical blood oxygenation was assessed during the stress paradigms using functional near-infrared spectroscopy (fNIRS). Further, we used ecological momentary assessment (EMA) of stress, rumination and mood to be able to correlate ruminative responses during induced stress and everyday rumination.

Our results showed that social stress but not physiological stress induced depressive rumination in MDD but not in HC. Further, rumination reactivity in response to social stress but not to physiological stress was significantly associated with rumination reactivity in everyday life as assessed with EMA. With respect to cortical oxygenation, MDD subjects showed hypoactivity in the Cognitive Control Network during the TSST, which mediated the differences between MDD and HC in post-stress rumination.

Our findings emphasize the role of negative social triggers in depressive rumination and validate the TSST as an induction method for depressive rumination. The results inform future developments in psychotherapeutic treatment for depressive rumination.

最近的研究强调沉思是各种精神障碍的重要维持因素。然而，操作化以及因此在实验环境中诱导反刍对生态有效性提出了重大挑战。由于压力似乎在引起思考的日常情况中发挥着关键作用，因此我们在评估行为和神经生理学测量时进行了两种压力范式。

旨在通过特里尔社会压力测试 (TSST) 复制先前关于诱发反刍的发现，并将其与生理（疼痛）压力、重度抑郁症 (MDD；n = 22) 患者和健康对照 (HC) 患者的临床样本进行比较；n = 23) 被招募。使用功能性近红外光谱（fNIRS）在压力范式期间评估皮质血液氧合。此外，我们使用压力、沉思和情绪的生态瞬时评估（EMA），以便能够将诱发压力和日常沉思期间的沉思反应关联起来。

我们的结果表明，社会压力而不是生理压力会导致 MDD 患者产生抑郁性沉思，而 HC 则不会。此外，根据 EMA 评估，对社会压力而非生理压力的反刍反应性与日常生活中的反刍反应性显着相关。在皮质氧合方面，MDD 受试者在 TSST 期间表现出认知控制网络的低活性，这介导了 MDD 和 HC 在应激后沉思方面的差异。

我们的研究结果强调了消极社会触发因素在抑郁性沉思中的作用，并验证了 TSST 作为抑郁性沉思的诱导方法。这些结果为抑郁沉思心理治疗的未来发展提供了信息。