人类应激内分泌轴功能状态的测量

HPA轴(下丘脑?垂体?肾上腺皮质轴, hypothalamic-pituitary-adrenal cortex axis)是人类重要的应激内分泌轴, 静息与应激条件下HPA轴的机能障碍能引发应激相关疾病, 而HPA轴机能障碍的表现和原因并不明确。皮质醇作为HPA轴的终端产物能直接反映HPA轴活动, 唾液皮质醇优于其他生物样本皮质醇的特性使其成为测量HPA轴活动的最优指标, 因此寻找到合适的唾液皮质醇标识来反映静息与应激条件下的HPA轴调节变化, 能促进理解HPA轴机能障碍与疾病间的神经内分泌通路。近来研究常用的是以皮质醇觉醒反应(cortisol -awakening response, CAR)与特里尔社会应激测试(Trier social stress test, TSST)来分别表示静息与应激条件下的HPA轴活动。未来研究将结合应激反应的生理、心理指标, 进一步考察HPA轴调节的脑网络, 为应激反应提供脑-神经内分泌通路的生物基础。     

经前期综合征女性的HPA轴功能失调：一项基于皮质醇水平的元分析

HPA轴(Hypothalamic-Pituitary-Adrenal,HPA)功能失调是压力相关情绪障碍形成或者恶化的决定因素。为系统评价基线状态和面临环境挑战时经前期综合征(PremenstrualSyndrome,PMS)女性基于皮质醇水平的HPA轴功能失调,对1990年以来的32项研究(总样本量N=1280)进行了定量整合,以期为女性经前期综合征的病因和干预提供参考。结果发现：在基线研究中, PMS女性黄体期的皮质醇含量显著低于普通女性,且受到皮质醇测量时间的调节作用;PMS女性卵泡期的皮质醇含量与普通女性无显著差异。环境挑战研究的结果与基线研究类似,PMS女性黄体期的皮质醇含量显著低于普通女性,但卵泡期的皮质醇含量与普通女性无显著差异。该结果提示压力内分泌轴的持久改变和面对压力时的HPA轴反应迟钝是PMS产生的可能病理机制。未来研究应关注应激调节策略来改善PMS的不良反应。     

创伤后应激障碍患者的正念疗法

本文回顾了正念干预在创伤后应激障碍(PTSD)领域的应用进展,分析了正念疗法的核心内容、作用机制,创伤后应激障碍患者正念干预具体实施过程及身心干预效果。分析表明,作为辅助药物治疗方式可降低创伤后应激障碍患者创伤后应激症状阳性率,调节皮质醇水平,缓解疼痛与疲乏症状,改善认知功能障碍、心理健康及情绪调节,以提高PTSD患者正念水平及生存质量,目前对于单纯用药疗效差的PTSD患者,正念疗法作为辅助治疗手段来解决其PTSD是非常有益的尝试。     

应激神经成像的研究述评

HPA轴(hypothalamic-pituitary-adrenal cortex axis)是人体的重要内分泌应激系统, 大脑通过控制HPA轴活动影响机体在应激情境中皮质醇(cortisol)的分泌, 同时皮质醇分泌对大脑也具有负反馈作用, 影响着大脑边缘系统的重塑; 海马、杏仁核、前额叶皮层和脑干都参与了应激反应中的皮质醇调节; 未来研究要进一步对应激源细化分类, 并且试图找到适合事件相关电位技术的社会心理性应激实验范式。     

急性心理性应激诱发的神经内分泌反应及其影响因素

急性心理性应激源分别通过下丘脑-脑垂体-肾上腺轴(hypothalamus–pituitary–adrenal axis,HPAA)和交感神经-肾上腺髓质轴(sympathetic-adrenal medulla axis)诱发神经内分泌反应。唾液皮质醇被认为是检测急性心理性应激所诱发的HPA轴反应的稳定指标。以特里尔社会应激测试(Trier Social Stress Test,TSST)及其变式作为应激源, 以HPA轴的反应作为应激指标, 影响个体在急性心理性应激情境中发生特异性神经内分泌反应的因素主要包括人口统计学、环境和应激频率三大方面, 未来应加强急性心理性应激所诱发的神经内分泌反应的纵向研究。     

儿童受欺负与急性社会应激中应激反应的关系

研究旨在考察受欺负经历与儿童下丘脑-垂体-肾上腺轴系统应激功能的关系。根据受欺负得分挑选出52名受欺负和未受欺负儿童,考察两类儿童在特里尔社会应激测验(Trier Social Stress Test,TSST)中的皮质醇分泌及主观紧张度的特征差异。结果发现:(1)在TSST中,受欺负者的皮质醇浓度显著高于未受欺负者;(2)两类儿童在TSST中的主观紧张度不存在显著差异。研究结果与慢性应激破坏HPA轴应激功能的过程是从敏化到钝化的理论假说相一致。     

高唤醒对创伤后应激障碍形成发展的影响及其神经机制

高唤醒是创伤后应激障碍(PTSD)的主要症状之一, 对创伤后应激障碍的形成与发展起核心作用。急性应激期产生的高唤醒可以预测其后PTSD的回避与麻木、再体验等症状的形成, 在创伤后早期, 降低唤醒程度可以减轻PTSD相关的症状表现。下丘脑-垂体-肾上腺轴异常变化会导致去甲肾上腺素(NE)、促肾上腺皮质激素释放因子(CRF)过度释放, 同时皮质醇(酮)水平下降, 这二者是高唤醒产生与维持的主要原因。另外, 5-羟色胺(5-HT)系统的高度激活也影响了高唤醒的形成。食欲素神经肽与NE、CRF与5-HT系统有密切的神经联系, 可能参与高唤醒的调节, 是近年来研究的一个热点。     

表观遗传修饰在应激诱发抑郁症中的作用

应激可以对个体的生理和行为产生负面影响, 甚至导致抑郁症, 但病因机制尚不清楚。近年来许多研究发现应激导致的表观遗传修饰变化影响抑郁症的发生。表观遗传是指DNA序列不发生变化, 但基因表达却发生了可遗传的改变。应激引起的HPA轴、单胺类递质、BDNF三个方面的表观遗传修饰的变化, 在抑郁症发生中发挥重要作用。最后提出了目前表观遗传机制研究的局限性和未来研究热点。     

灾后孤儿创伤后应激障碍的发生发展及其认知神经机制

灾后孤儿亲历双重重大创伤, 是创伤后应激障碍(post-traumatic stress disorder, PTSD)的高发群体; 同时, 巨大创伤对其认知功能和行为模式也带来一定程度的影响。本研究拟以灾后孤儿这一特殊群体为研究对象, 考察“PTSD发生发展及其认知神经机制”, 具体如下：(1) 采用序列研究设计, 展开灾后孤儿PTSD流行病学调查, 描述其PTSD发生发展、变化的轨迹和时程特点; (2) 展开横断研究, 考察灾后孤儿认知发展特点, 并通过结构方程模型, 揭示其PTSD发生发展的心理行为机制; (3) 采用眼动和脑电技术展开比较研究, 考察罹患PTSD孤儿的认知神经机制。本研究的研究结果将对今后的灾后孤儿安置及心理援助提供科学建议; 为有针对性地提供心理干预、制定心理干预的总体规划提供科学依据; 力争为今后孤儿的创伤心理的诊断、干预效果评估提供科学客观的指标和方法。     

PTSD个体对创伤相关刺激的情绪标识效应研究

采用三因素混合实验设计,结合情绪标识范式考察创伤后应激障碍（PTSD）个体对创伤相关图与负性情绪面孔的情绪标识效应。结果发现：PTSD组的情绪标识任务抑制了创伤相关图对之后奇偶判断任务的干扰,表现出显著的情绪标识效应;而对负性情绪面孔的情绪标识效应不显著。该研究表明将谈话疗法用于PTSD患者的心理危机干预是有效的。     

The neuroendocrinology of posttraumatic stress disorder: new directions

Studies of the hypothalamic-pituitary-adrenal (HPA) axis in persons with posttraumatic stress disorder (PTSD) have produced variable findings. This review focuses on the factors likely to have affected the outcome of these studies, including population characteristics and experimental design. Also discussed is a possible role for the adrenal neurosteroid dehydroepiandrosterone (DHEA) as a mediator of HPA axis adaptation to extreme stress and the psychiatric symptoms associated with PTSD. The antiglucocorticoid properties of DHEA may contribute to an upregulation of HPA axis responses as well as mitigate possible deleterious effects of high cortisol levels on the brain in some PTSD subpopulations. The neuromodulatory effects of DHEA and its metabolite DHEAS at gamma-aminobutyric acid and N-methyl-D-aspartate receptors in the brain may contribute to psychiatric symptoms associated with PTSD. The possible importance of other neurohormone systems in modulating HPA axis and symptom responses to traumatic stress is also discussed. Understanding the complex interactions of these stress-responsive neurosteroid and peptide systems may help explain the variability in patterns of HPA axis adaptation, brain changes, and psychiatric symptoms observed in PTSD and lead to better targeting of preventive and therapeutic interventions.     

皮质醇日常节律与儿童问题行为及心理社会因素的关系

HPA轴(下丘脑?垂体?肾上腺皮质轴, hypothalamic-pituitary-adrenal cortex axis)是人体应对压力的重要神经内分泌系统, 其终产物皮质醇常作为测量压力的生物学指标。目前的研究多通过皮质醇日常节律表示静息状态下HPA轴的活动, 而日常节律因其较高的稳定性和可靠性成为儿童生理健康评估的最佳指标。儿童期迅速发育的神经内分泌系统与儿童的行为相互作用, 并受到多种心理社会因素的影响。以往研究主要关注皮质醇日常节律与儿童问题行为及心理社会因素的关系, 未来研究应讨论逆境条件下影响儿童成长的危险性因素和保护性因素, 并探索环境对儿童行为影响可能存在的内分泌机制。     

Adolescent Personality: Associations With Basal,Awakening, and Stress‐Induced Cortisol Responses

The purpose of the present study was to investigate the associations between personality facets and hypothalamic‐pituitary‐adrenal (HPA) axis functioning. Previous studies have mainly focussed on stress‐induced HPA‐axis activation. We hypothesized that other characteristics of HPA‐axis functioning would have a stronger association with personality based on the neuroendocrine literature. Data (n = 343) were used from the TRacking Adolescents' Individual Lives Survey (TRAILS), a large prospective cohort study of Dutch adolescents. We studied the association between facets of Neuroticism, Extraversion, and Conscientiousness and basal cortisol, the cortisol awakening response (CAR), and four measures of stress‐induced HPA‐axis activity. Basal cortisol levels were related to facets of all three personality traits. The CAR and stress‐induced cortisol were not related to personality. Possibly due to its more trait‐like nature, basal cortisol seems more informative than stress‐induced cortisol when investigating trait‐like characteristics such as personality facets.     

Response of the pituitary-adrenal axis in terms of type a behaviour,hostility and vital exhaustion in healthy middle-aged men

Abstract

Pituitary-adrenal axis was studied in terms of Type A behaviour, hostility and vital exhaustion among 69 healthy middle-aged men. The results showed that psychological factors could explain a significant proportion of the biologically manipulated responses of HPA axis, but they worked in different ways. Type A behaviour was related to a high level of mean basal ACTH and a low level of cortisol response to ACTH stimulation after dexamethasone suppression; hostility was related to a high level of mean basal cortisol and a high cortisol in cortisol/ACTH ratio, while vital exhaustion was characterized by a low level of mean basal ACTH and a decreased ACTH in relation to cortisol. The adrenocortical patterns, i.e. a high ACTH-low cortisol; a high cortisol; and a low ACTH-low mean basal cortisol, as related to Type A behaviour, hostility and exhaustion, respectively, are in line with the traditional physiological stress model and suggest that different adrenocortical responses might be able to identify different mental stress processes. Sense of control has been suggested to be a key concept for psychological understanding of this finding.     

Effortful control and parenting: Associations with HPA axis reactivity in early childhood

While activation of the hypothalamic‐pituitary‐adrenal (HPA) axis is an adaptive response to stress, excessive HPA axis reactivity may be an important marker of childhood vulnerability to psychopathology. Parenting, including parent affect during parent–child interactions, may play an important role in shaping the developing HPA system; however, the association of parent affect may be moderated by child factors, especially children's emerging self‐regulatory skills. We therefore tested the relationship between parent affectivity and 160 preschoolers’ cortisol reactivity during a laboratory visit, examining children's effortful control (EC) as a moderator. Greater parent negative affectivity was related to greater initial and increasing cortisol over time, but only when children were low in EC. Higher parent positive affectivity was related to a higher baseline cortisol for children with low EC and lower baseline cortisol for children with high EC. Results indicate that children's EC moderates the extent to which parent affect shapes stress reactive systems in early childhood.     

Cortisol Response Following Exposure Treatment for PTSD in Rape Victims

This study examined changes in salivary cortisol levels pre- to posttreatment in adult female rape victims diagnosed with posttraumatic stress disorder (PTSD) randomly assigned to be treated with either prolonged exposure therapy or eye movement desensitization and reprocessing. Salivary cortisol was collected at baseline, Session 3, and Session 9. A significant decrease in salivary cortisol levels was observed in individuals classified as treatment responders in both treatment conditions. Findings suggest that successful exposure-based treatments for PTSD that result in trauma-related and depressive symptom reduction may impact the action of the hypothalamic–pituitary–adrenal axis as measured by changes in level of salivary cortisol from pre- to posttreatment.     

Gender differences in cardiovascular and hypothalamic-pituitary-adrenal axis responses to psychological stress in healthy older adult men and women

Gender differences in the neuroendocrine and cardiovascular response to psychological stress may contribute to the gender differences in the prevalence of diseases associated with hypothalamic-pituitary-adrenal (HPA) axis reactivity such as cardiovascular disease (CVD), diabetes and hypertension. We measured plasma ACTH, cortisol, heart rate (HR), and blood pressure (BP) responses in 8 men and 8 women (55-75 years) exposed to the Matt Stress Reactivity Protocol (MSRP), a psychological challenge. The MSRP elicited significant increases in HR, systolic-, and diastolic BP, ACTH and cortisol (all p<0.01). Men had significantly greater cortisol and diastolic BP responses compared to women (p<0.05). Additionally, a positive correlation between the ACTH and cortisol responses was only found in the males (r=0.71, p<0.05). There were no group differences in HR, systolic BP, or ACTH responses. We conclude, that among older adults, men respond to psychological stress with greater increases in cortisol, compared to women. This greater activation of the HPA axis could translate into an elevated risk for CVD, diabetes and hypertension and may be related to the higher prevalence of these diseases in males. Gender differences in brain structures and/or cognitive processes may be responsible for these sexually dimorphic stress responses.