Zefferman Matthew R, Baumgarten Michael D, Trumble Benjamin C, Mathew Sarah
Department of Defense Analysis, Naval Postgraduate School, Monterey, CA, 93943, USA.
Institute of Human Origins, Arizona State University, Tempe, AZ, 85281, USA.
Evol Med Public Health. 2025 Feb 17;13(1):77-91. doi: 10.1093/emph/eoaf004. eCollection 2025.
Research in industrialized populations suggests that posttraumatic stress disorder (PTSD) may be associated with decreased cortisol or testosterone sensitivity, resulting in a blunted diurnal rhythm. However, the evolutionary implications of this association are unclear. Studies have primarily been conducted in Western industrialized populations, so we do not know whether hormonal blunting is a reliable physiological response to PTSD or stems from factors unique to industrialized settings. Furthermore, existing studies combine PTSD from diverse types of traumas, and comparison groups with and without PTSD differ along multiple dimensions, making it hard to know if PTSD or other life factors drive the blunted cortisol response. We conducted a study among = 60 male Turkana pastoralists, aged between about 18-65 years in Kenya, exposed to high levels of lethal inter-ethnic cattle raiding. 28% of men in this area have PTSD symptom severity that would qualify them for a provisional PTSD diagnosis. Saliva samples were collected at three points to compare the cortisol and testosterone profiles of Turkana warriors with and without PTSD. Contrary to existing work, our preregistered analysis found little evidence for a difference in the hormonal profiles of warriors with high versus low PTSD symptom severity. Our results imply that the relationship between PTSD and hormonal diurnal variation may vary across populations and ecologies or that the association documented in Western populations stems from other correlated life factors. Studies in a wider range of populations and ecological contexts are needed to understand the evolutionary underpinnings of hormonal responses to trauma.
对工业化人群的研究表明，创伤后应激障碍（PTSD）可能与皮质醇或睾酮敏感性降低有关，从而导致昼夜节律减弱。然而，这种关联的进化意义尚不清楚。相关研究主要在西方工业化人群中进行，所以我们不知道激素水平降低是对PTSD的一种可靠生理反应，还是源于工业化环境特有的因素。此外，现有研究将来自不同类型创伤的PTSD合并在一起，有PTSD和没有PTSD的对照组在多个维度上存在差异，这使得我们很难确定是PTSD还是其他生活因素导致了皮质醇反应减弱。我们对肯尼亚60名年龄在18至65岁之间、遭受高水平致命族际牲畜劫掠的图尔卡纳牧民男性进行了一项研究。该地区28%的男性PTSD症状严重程度符合初步PTSD诊断标准。在三个时间点采集唾液样本，以比较有和没有PTSD的图尔卡纳勇士的皮质醇和睾酮水平。与现有研究结果相反，我们预先登记的分析几乎没有发现高PTSD症状严重程度与低PTSD症状严重程度的勇士在激素水平上存在差异的证据。我们的结果表明，PTSD与激素昼夜变化之间的关系可能因人群和生态环境而异，或者西方人群中记录的这种关联源于其他相关的生活因素。需要在更广泛的人群和生态环境中进行研究，以了解激素对创伤反应的进化基础。
