OBJECTIVE To examine whether cumulative cortisol production changes during a period of increased demands when cortisol and stress are assessed concurrently. The study also compared stress perceptions vs. cumulative stressful events on their respective association with cortisol output. Finally, it explored whether certain types of stressful events, those involving school/job performance or social-evaluative threat, were linked to cortisol levels across multiple weeks. METHOD The current study assessed cumulative cortisol production via hair sample in 56 undergraduates (88 % female) during both lower stress (summer break) and higher stress (academic term) periods. During the latter, both negative events (checklist) and stress perceptions were assessed weekly, and these reports were aggregated across the 10-weeks to minimize retrospective bias. RESULTS Cortisol levels in hair samples were significantly higher (d = 0.84) during the academic term (M = 14.24 pg/mg, SD = 11.36) compared to summer break (M = 8.00 pg/mg, SD = 4.14), suggesting greater cumulative exposure to cortisol. Although perceived stress was not associated with cortisol levels (rpartial(53) = .10, p = 0.46), exposure to more stressful events (rpartial(53) = .27, p = 0.047), particularly events involving academic demands (rpartial(53) = .37, p = 0.006), or negative evaluation/social rejection (rpartial(53) = .27, p = 0.045), was positively associated with cumulative cortisol exposure. CONCLUSIONS This study demonstrates that cortisol levels in hair may be linked to cumulative exposure to stressors when measured concurrently (3 months), and that stressful events, rather than perceptions, are reflected in HPA axis activity. Real-world stressors involving performance demands and social-evaluative threat accumulate to enhance cortisol production, consistent with their acute HPA effects in the lab. Hair samples may provide a window into the past by allowing researchers to feasibly assess cortisol production before, during, and after the onset of a chronic stressor.

中文翻译：

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在学期期间累积皮质醇暴露增加：与表现相关和社会评估压力源的联系

目的 检验当同时评估皮质醇和压力时，在需求增加的时期累积皮质醇产生是否会发生变化。该研究还比较了压力感知与累积压力事件各自与皮质醇输出的关联。最后，它探讨了某些类型的压力事件，包括学校/工作表现或社会评价威胁，是否与数周内的皮质醇水平有关。方法 当前的研究通过头发样本评估了 56 名本科生（88% 女性）在较低压力（暑假）和较高压力（学术学期）期间的累积皮质醇产量。在后者期间，每周都会评估负面事件（清单）和压力感知，并且这些报告在 10 周内汇总，以最大程度地减少回顾性偏差。结果 与暑假 (M = 8.00 pg/mg, SD = 4.14) 相比，学期期间头发样本中的皮质醇水平 (M = 14.24 pg/mg, SD = 11.36) 显着更高 (d = 0.84)，表明累积量更大暴露于皮质醇。尽管感知压力与皮质醇水平无关 (rpartial(53) = .10, p = 0.46)，但暴露于压力更大的事件 (rpartial(53) = .27, p = 0.047)，尤其是涉及学术要求的事件 (rpartial( 53) = .37, p = 0.006) 或负面评价/社会排斥（rpartial(53) = .27, p = 0.045）与累积皮质醇暴露呈正相关。结论 本研究表明，头发中的皮质醇水平可能与同时测量（3 个月）时累积暴露于压力源有关，并且压力事件而不是感知反映在 HPA 轴活动中。涉及表现要求和社会评价威胁的现实世界压力源会累积以增强皮质醇的产生，这与它们在实验室中的急性 HPA 效应一致。头发样本可以让研究人员在慢性压力源出现之前、期间和之后可行地评估皮质醇的产生，从而提供一扇了解过去的窗口。