Department of Psychology, University of Westminster, London, UK.
Psychoneuroendocrinology. 2011 Jul;36(6):816-23. doi: 10.1016/j.psyneuen.2010.11.003. Epub 2010 Dec 9.
This study compared the daily pattern of free salivary cortisol secretion in winter and in summer between two groups; participants with self-assessed seasonal affective disorder (SAD) and age- and sex-matched healthy controls. Fifty-two participants completed the study with an equal number in each group. The diurnal pattern of cortisol secretion was assessed across two consecutive weekdays in summer, and two in winter, with conditions being counterbalanced. On each study day participants collected multiple saliva samples in the domestic setting to capture the cortisol awakening response (CAR) and declining levels across the day. In addition, perceived stress, anxiety, depression, state stress and state arousal were assessed using validated questionnaires. There was no evidence for any seasonal changes in psychological data or cortisol pattern for the healthy control population. In summer, self-assessed SAD and control participants had similar psychological and cortisol profiles. In winter however, SAD participants reported greater depression, stress and anxiety, and lower levels of arousal. Furthermore, the CAR was significantly attenuated in SAD participants during winter months. There was no difference in cortisol levels during the rest of the day between controls and SAD participants in winter. In line with the above findings and previous research, there was an inverse relationship between the increase in cortisol following awakening and a measure of seasonality in winter. Furthermore in winter, a general dysphoria construct correlated inversely with the CAR, indicating that participants reporting greater depression, stress and anxiety and lower arousal, exhibited lower CARs. In conclusion, during the shortened photoperiod in winter, the cortisol response to awakening is attenuated in participants with self-assessed SAD in comparison to controls. These findings contribute to the understanding of the physiology of SAD.
本研究比较了两组人群在冬季和夏季的自由唾液皮质醇分泌的日常模式；一组是自我评估为季节性情感障碍（SAD）的患者，另一组是年龄和性别匹配的健康对照者。共有 52 名参与者完成了研究，每组各有 26 人。在夏季和冬季，分别连续两天评估皮质醇分泌的昼夜模式，条件相互平衡。在每个研究日，参与者在家庭环境中采集多个唾液样本，以捕捉皮质醇觉醒反应（CAR）和全天的下降水平。此外，使用经过验证的问卷评估感知压力、焦虑、抑郁、状态压力和状态唤醒。健康对照组的心理数据或皮质醇模式没有任何季节性变化的证据。在夏季，自我评估的 SAD 和对照组参与者具有相似的心理和皮质醇特征。然而，在冬季，SAD 参与者报告了更大的抑郁、压力和焦虑，以及更低的唤醒水平。此外，SAD 参与者在冬季的 CAR 明显减弱。在冬季，对照组和 SAD 参与者在其余时间的皮质醇水平没有差异。与上述发现和以前的研究一致，觉醒后皮质醇的增加与冬季季节性的变化呈负相关。此外，在冬季，一般的烦躁不安与 CAR 呈负相关，表明报告有更大的抑郁、压力和焦虑以及更低的唤醒的参与者，其 CAR 较低。总之，在冬季短的光周期期间，与对照组相比，自我评估为 SAD 的参与者的觉醒后皮质醇反应减弱。这些发现有助于理解 SAD 的生理学。
