Stress-The International Journal on the Biology of Stress最新文献

{"title":"17β-estradiol regulates the behavioral, neuronal, and physiological responses to acute witness stress in female rats.","authors":"Brittany S Pate, Sarah E Mott, Cora E Smiley, Samantha J Bouknight, Evelynn N Harrington, Susan K Wood","doi":"10.1080/10253890.2026.2709373","DOIUrl":"10.1080/10253890.2026.2709373","url":null,"abstract":"<p><p>Females are more than twice as likely as males to develop stress-related conditions such as depression, anxiety, and PTSD, but the neural mechanisms underlying this heightened stress sensitivity are unknown. Recent evidence demonstrates that cyclical ovarian hormones may contribute to the augmented stress responses observed in females. Thus, the current experiments were designed to determine the role of estrogen in the neuronal, behavioral, and physiological responses to social stress in female rats. Adult, female, Sprague-Dawley rats underwent ovariectomy or a sham procedure and were implanted with an intravenous catheter in the right jugular vein. One week later, rats were treated with 17β-Estradiol (10 μg) or vehicle prior to observing social defeat between two male rats (witness stress, WS) or undergoing control handling. Burying behavior was assessed during WS/control, blood samples were collected immediately following WS/control for analysis of circulating epinephrine, and brains were collected two hours after WS/control for quantification of cfos in the sexually dimorphic and stress sensitive locus coeruleus (LC). WS-exposed females exhibited a distinct burying phenotype that was attenuated by ovariectomy but reinstated with 17β-Estradiol pretreatment. Similarly, plasma epinephrine and LC cfos were elevated following WS selectively in females with intact circulating ovarian hormones. These physiological responses were blunted by ovariectomy and reinstated by 17β-Estradiol treatment prior to WS. Together, these data highlight a critical role for estrogen in the biobehavioral responses to acute psychosocial stress in females.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2709373"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13536966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148801219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cardiac-brain integration and stress: a mechanistic role for the heartbeat-evoked potential?","authors":"Rania-Iman Virjee, Sarah N Garfinkel","doi":"10.1080/10253890.2026.2727608","DOIUrl":"https://doi.org/10.1080/10253890.2026.2727608","url":null,"abstract":"<p><p>The heartbeat-evoked potential (HEP) is an electrophysiological marker of cortical heartbeat processing that offers an informative index of neural interoception (i.e. the central sensing and integration of internal bodily signals). Stress is known to influence both peripheral and central physiology, and the HEP provides a metric of heart-brain integration with explanatory power beyond that of either the cardiac response or the brain alone. Emerging evidence suggests that the HEP can provide informative insight into individual differences across a range of clinical and emotional measures, with the opportunity to advance our understanding of the mechanisms underlying acute and chronic stress responses. This short communication highlights the potential of the HEP as a future neurophysiological marker in stress research and provides a roadmap for future research to advance its investigation within the field of stress.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2727608"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148892815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Activity dynamics in the NPY neuronal signaling of mPFC in response to an air puff.","authors":"Eugene Dimitrov, Ted Usdin, Janice H Urban","doi":"10.1080/10253890.2026.2666067","DOIUrl":"10.1080/10253890.2026.2666067","url":null,"abstract":"&lt;p&gt;&lt;p&gt;These studies were designed to elucidate the role of NPY in modulating the responses of mPFC to acute stress in mice. Fiberoptic photometry recorded a robust increase in the NPY fluorescent signal in the mPFC during exploration of the elevated O-maze (EOM). An application of a single air puff (stressor) increased anxiety-like behavior and was associated with a decreased NPY signal in the mPFC. Antagonism of Y1 receptors (Y1r) in the mPFC with BIBO3304 decreased time spent in the open compartments of the EOM, identifying a role for endogenous NPY in modulating anxiety-like behavior. While the chemogenetic actuation of local parvalbumin neurons (PVs) increased anxiety-like behavior, an injection of NPY into the mPFC decreased the Ca&lt;sup&gt;2+&lt;/sup&gt; signal detected from PVs in response to the stressor, an indication of NPY-mediated inhibition of PVs. Injection of NPY into the mPFC increased, while injection of BIBO3304 decreased, the Ca&lt;sup&gt;2+&lt;/sup&gt; signal detected from mPFC→BLA projections in response to the air puff stress. Viral tracing demonstrated that, while NPY neurons in the mPFC receive monosynaptic input from many brain regions, their axonal output is restricted to layers of the mPFC, with one of the targets being local PVs. These results demonstrate that ongoing inhibition of PV activity in the mPFC by NPY via Y1r influences anxiety-like activity in mice, likely through strengthening mPFC output to the BLA. Subjecting animals to an acute stress disrupts this circuitry, providing further and new support for a role of NPY in the mPFC and the modulation of stress-related behaviors. These studies were designed to elucidate the role of NPY in modulating the responses of mPFC microcircuitry to acute stress in mice. Using an NPY biosensor in the mPFC, fiberoptic photometry recorded a robust increase in the NPY fluorescent signal during exploration of the elevated O-maze (EOM). An application of a single air puff (stressor) increased anxiety-like behavior in the EOM and was associated with a decreased NPY signal in the mPFC, supporting a possible link between NPY signaling and levels of anxiety. Antagonism of Y1 receptors (Y1r) in the mPFC with BIBO3304 decreased time spent in the open compartments of the EOM, identifying a role for endogenous NPY in modulating anxiety-like behavior. The chemogenetic actuation of local parvalbumin neurons (PVs) increased anxiety-like behavior. Conversely, an injection of NPY into the mPFC decreased the Ca&lt;sup&gt;2+&lt;/sup&gt; signal detected from PVs in response to the stressor, an indication of NPY-mediated inhibition of PVs. Injection of NPY into the mPFC significantly increased, while injection of BIBO3304 decreased, the Ca&lt;sup&gt;2+&lt;/sup&gt; signal detected from mPFC→BLA projections in response to the air puff stress. Viral tracing demonstrated that, while NPY neurons in the mPFC receive monosynaptic input from many brain regions, their axonal output is restricted to layers of the mPFC, with one of the targets being loc","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2666067"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147788523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early-life stress alters adult social and coping behaviors in a sex-specific and domain-dependent manner.","authors":"Ernest Cote, Matthew Kodsi, Juan Marcos Alarcon","doi":"10.1080/10253890.2025.2611616","DOIUrl":"10.1080/10253890.2025.2611616","url":null,"abstract":"<p><p>Early Life Stress (ELS) increases the risk for mental health issues in humans, notably in major depression and anxiety disorders. ELS is frequently modeled in laboratory rodents by disrupting the early postnatal environment. Literature on ELS is expanding, yet studies on sex-specific differences remain mixed. We utilized a novel ELS protocol that subjected mouse pups of both sexes to maternal separation and removed pup-to-pup contact comfort during postnatal days 10 to 17. We hypothesized that this ELS protocol would induce depressive and anxiety-like phenotypes persisting into adulthood, with greater vulnerability in females. A second cohort reared under normal conditions until adulthood was subjected to forced swim, mimicking adult-onset stress (AS). ELS, AS, and control animals (reared under normal conditions) underwent open field, social interaction, and tail suspension tests. In open field, AS mice spent significantly less time in center than controls. Social interaction showed significant effects of treatment and sex, with stress exposure increasing familiar-mouse interaction time and reducing the sex difference observed in controls. Tail suspension testing revealed a significant decrease in latency to immobility for stress groups compared to controls. Total time immobile showed significant group and interaction effects, with stress groups showing more time immobile. Both social interaction and tail suspension revealed a sex difference in controls, eliminated in stress groups. This ELS protocol produces lasting alterations in adult social and coping-related behaviors and demonstrates multiple sex-specific outcomes.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2611616"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145901730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association between allostatic load and thyroid function in U.S. adults: a cross-sectional study based on NHANES data.","authors":"Dai Zhuolin, Huang Chun, Xinliang Su","doi":"10.1080/10253890.2026.2653858","DOIUrl":"10.1080/10253890.2026.2653858","url":null,"abstract":"<p><p>Chronic stress may contribute to endocrine dysregulation. The allostatic load (AL), an indicator of cumulative physiological burden across multiple systems, has unclear associations with thyroid function. We analyzed 5525 adults (2678 men and 2847 women) from NHANES 2007-2010. The participants were categorized into allostatic load score (ALS) quartiles: Q1 (<i>n</i> = 2582), Q2 (<i>n</i> = 1394), Q3 (<i>n</i> = 1003), and Q4 (<i>n</i> = 546). The ALS was constructed from eight cardiovascular, metabolic, and inflammatory biomarkers. Thyroid function was assessed (TSH, FT3, FT4, TgAb, and TPOAb) and categorized as thyroid dysfunction. Survey-weighted multivariable linear and logistic models estimated associations; trend tests and restricted cubic splines (RCS) assessed linearity. Subgroup and interaction analyses examined effect modification, and sensitivity analyses evaluated robustness. ALS was positively associated with higher TSH (<i>β</i> = 0.038, 95% CI: 0.019-0.057, <i>p</i> = 0.001) and FT3 (<i>β</i> = 0.005, 95% CI: 0.003-0.008, <i>p</i> < 0.001). No significant associations were observed for FT4, TPOAb, or TgAb. TSH increased linearly across ALS quartiles (<i>p</i>-trend < 0.001). Restricted cubic splines indicated no overall departure from linearity; in sex-stratified analyses, the association was linear in women and nonlinear in men. Significant interactions with age and race (<i>p</i> < 0.05) indicate that the ALS-TSH association differs by demographics. The results were consistent across the subgroup and sensitivity analyses. Our study suggested a significant positive association between AL and TSH levels. Further research is needed to clarify the mechanisms linking stress and thyroid function.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2653858"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147629223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vicarious stress-induced emotional contagion drives sex-dependent behavioral and neurochemical alterations in mice.","authors":"N Martínez-Álvarez, E Hernández-Hernández, I Erkizia-Santamaría, A M Erdozain, J J Meana, J E Ortega","doi":"10.1080/10253890.2026.2686638","DOIUrl":"10.1080/10253890.2026.2686638","url":null,"abstract":"<p><p>Vicarious stress (VS), defined as exposure to stressed peers without direct stress experience, represents a form of purely emotional stress with potential translational relevance. Here, we investigated the behavioral and neurochemical consequences of VS in male and female mice. Behavioral assessments consisted of the open field test (OFT) and elevated plus maze (EPM) for anxiety-like behavior, the Barnes maze (BM) for visuospatial learning and cognitive flexibility, and the social preference test (SPT) for social behavior. VS did not significantly alter anxiety-like measures in either sex. In contrast, learning-curves were significantly affected during BM acquisition, although this effect did not reach statistical significance in reversal learning or test phases. Social behavior was consistently disrupted in both male and female VS mice, highlighting social avoidance as a robust outcome of emotional stress. Neurochemical analyses revealed region- and sex-dependent alterations in monoaminergic systems. Serotonin concentrations increased in both brain cortex and hippocampus, while dopamine and noradrenaline concentrations showed region- and sex-dependent alterations respectively. These findings suggest that VS engages monoaminergic circuits implicated in emotion regulation, with distinct sex-specific patterns. Overall, our results demonstrate that indirect exposure to stressed peers is sufficient to modulate learning, social behavior, and monoaminergic signaling, even in the absence of direct stress experience. These findings underscore the relevance of emotional contagion in stress research and highlight the importance of controlling environmental and social factors to improve reproducibility in preclinical stress models.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2686638"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148279887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intensity-dependent associations of physical activity and cardiorespiratory fitness with hair cortisol concentrations in the context of lifetime air pollution exposure.","authors":"Veronika Cibulcova, Steriani Elavsky, Lukas Cipryan, Marta Jackowska, Tomas Dostal, Vitezslav Jirik, Daniel Jandacka, Vera Kr Jandackova","doi":"10.1080/10253890.2026.2721526","DOIUrl":"https://doi.org/10.1080/10253890.2026.2721526","url":null,"abstract":"<p><p>Hair cortisol concentration (HCC) is used as a biomarker of chronic stress. While evidence linking HCC to physical activity is mixed, associations with cardiorespiratory fitness remain unexplored, and the contribution of long-term ambient air pollution is unclear. This study examined associations of HCC with objectively and subjectively assessed moderate and vigorous physical activity, cardiorespiratory fitness, and estimated lifetime ambient air pollution exposure. Data were obtained from a subsample of adults (<i>N</i> = 133; 87% women) participating in the Healthy Aging in an Industrial Environment-Programme 4 study (4HAIE). HCC was quantified from 3-cm hair segments using liquid chromatography-tandem mass spectrometry, reflecting cortisol exposure over approximately 3 months. Physical activity was assessed using the Leisure-Time Exercise Questionnaire (LTEQ) and 14-day Fitbit monitoring, and cardiorespiratory fitness by peak oxygen uptake (VO₂peak). Lifetime exposure to particulate matter (PM_2.5 and PM₁₀) and nitrogen dioxide (NO₂) was estimated from residential histories and historical air pollution models. Associations were examined using multiple linear regression and hierarchical models. Vigorous physical activity was positively associated with HCC in both self-reported (LTEQ: B = 0.010, <i>p</i> = 0.042) and objectively measured data (Fitbit: B = 0.006, <i>p</i> = 0.044). VO₂peak was initially associated with higher HCC (B = 0.019, <i>p</i> = 0.041), but this association was attenuated after inclusion of vigorous physical activity. Neither moderate physical activity nor lifetime air pollution exposure was significantly associated with HCC. These findings suggest that vigorous physical activity may contribute to higher HCC, highlighting the importance of considering physical activity intensity when interpreting HCC as a biomarker of chronic stress.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2721526"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148931888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The association between hair cortisol levels, Epstein-Barr virus infections and chronic fatigue in adolescents.","authors":"Berit Elise Bergem Kongsnes, Tarjei Tørre Asprusten, Vegard Bruun Bratholm Wyller, Maria Pedersen","doi":"10.1080/10253890.2026.2638303","DOIUrl":"10.1080/10253890.2026.2638303","url":null,"abstract":"<p><p>Chronic fatigue after Epstein-Barr virus (EBV) infection is a significant health problem among adolescents, yet its underlying mechanisms remain unclear. This study investigated whether preinfection hair cortisol levels predict chronic fatigue following acute EBV infection and examined the associations between hair cortisol and concurrent fatigue during acute infection, six months postinfection, and in healthy controls. This study is part of the CEBA project (Chronic Fatigue following Acute Epstein-Barr Virus Infection in Adolescents). Hair samples for cortisol measurements were obtained from 192 adolescents aged 12-20 years during acute EBV infection and again six months later, and from 66 age- and sex-matched healthy controls. Fatigue was measured by the total score on the Chalder Fatigue Questionnaire. Group comparisons were performed using nonparametric tests, and associations were examined with linear regression analyses. Adolescents with EBV infection had significantly higher preinfection hair cortisol levels (median 5.12, IQR: 3.27-8.76) compared with healthy controls did (median 3.90, IQR: 2.61-6.19) and with their own levels six months later (median 3.74, IQR: 2.46-6.52). A trend toward a positive association between preinfection hair cortisol and fatigue during acute infection, became significantly negative six months later. No associations were found among controls. Preinfection hair cortisol concentration did not predict chronic fatigue six months after acute EBV infection. Elevated preinfection hair cortisol may reflect stress-related vulnerability to infection, and the shifted from a positive to a negative association over time, suggests that HPA-axis alterations are more likely a consequence rather than a cause of chronic fatigue.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2638303"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147345635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of heat exposure on pulse wave dynamics using pulse rate variability.","authors":"Kumari Akanksha, José Javier Reyes-Lagos, Yogender Aggarwal, Rakesh Kumar Sinha","doi":"10.1080/10253890.2026.2643515","DOIUrl":"10.1080/10253890.2026.2643515","url":null,"abstract":"<p><p>Heat stress is a well-known stressor that causes heat illnesses. Heat stress causes significant cardiovascular changes needed for temperature control through vasodilation and sweating. Therefore, the objective was to assess photoplethysmogram (PPG)-derived pulse rate variability (PRV) characteristics for predicting heat stress in a preclinical model. Ten male Wistar rats (10-12 weeks old) were divided into control (<i>n </i>= 5) and experimental (<i>n </i>= 5) groups. The subjects were exposed to 38 ± 1 °C and 24 ± 1 °C for 30 minutes daily for five consecutive days. The rectal temperature, electrocardiogram (ECG), and PPG signals were recorded after the 5th day of exposure. Pulse rate variability (PRV) was analyzed using time-domain, frequency-domain, and nonlinear metrics derived from PPG signals. Pulse arrival time (PAT) was estimated from synchronized ECG-PPG recordings and used to compute pulse wave velocity (PWV). A Naive Bayes classifier was trained using selected PRV features to distinguish heat stress from control conditions. The core body temperature increased by 0.5 °C (<i>p</i> < 0.05) under elevated heat stress for five consecutive days. The results also indicated a reduction in PRV under heat stress, suggesting increased sympathetic and withdrawal of parasympathetic activity, highlighting the physiological alterations induced by heat stress. A slight increase in pulse wave velocity (PWV) was also observed, revealing minimal heat-related changes in arterial stiffness. Further, the PRV parameters-based Naive Bayes algorithm demonstrated an accuracy of 94.58% in the prediction of the heat stress event. The findings highlighted the withdrawal of parasympathetic activity and the potential of PPG-derived parameters as a modality for predicting heat stress events.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2643515"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147500485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-week essential oil inhalation treatment modulates the cortisol awakening response and improves self-reported symptoms in stressed adults.","authors":"Mark Moss, Anna Balen, Gavin Cowper, Sophie Swinburne, Anna Turner, Mark Wetherell","doi":"10.1080/10253890.2026.2684156","DOIUrl":"10.1080/10253890.2026.2684156","url":null,"abstract":"<p><p>We investigated the impact of the inhalation of a blended essential oil aroma on markers of chronic stress in otherwise healthy adults. The \"Stressless™\" essential oil blend employed is a proprietary product designed and created by the International Federation of Aromatherapists as a treatment for stress. Seventy-five adults took part in the balanced placebo-controlled design study. Fifty participants with self-reported stress were randomly allocated to undergo two-weeks of an aroma inhalation protocol balanced with two-weeks of perceptible placebo inhalation. A no intervention control group provided data on the variables across the same study period. The dependent variables were the cortisol awakening response (CAR) and subjective measures of stress and associated symptoms assessed at four time points. Data analysis revealed that in stressed individuals exhibiting a suppressed CAR at basal levels, \"Stressless™\" aromatherapy normalized this physiological parameter to control group levels. However, this modulatory effect was found to be limited to the intervention period and did not show persistence after application. In contrast, the continued improvement in the subjective stress and anxiety scores after the intervention suggested that the effect of aroma on psychological well-being is more resistant. In conclusion, the \"Stressless™\" essential oil blend may be considered an effective non-invasive tool for stress management in otherwise healthy individuals. These observed effects are discussed within the framework of the regulatory mechanisms of olfaction on the limbic system and the hypothalamic-pituitary-adrenal (HPA) axis.</p>","PeriodicalId":51173,"journal":{"name":"Stress-The International Journal on the Biology of Stress","volume":"29 1","pages":"2684156"},"PeriodicalIF":3.7,"publicationDate":"2026-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148207052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}