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22 papers
This paper is a meta-analysis of more than 300 studies in humans that looked at links between psychological stress and measures of the immune system. It found that very short, acute stressors (minutes) were tied to increases in some natural (innate) immune measures and decreases in some specific (adaptive) immune…
This review examines studies on how testosterone relates to anxiety and depression and how that might help explain sex differences in these disorders. About 18% of U.S. adults have an anxiety disorder each year and about 7% have major depressive disorder, and women are more than twice as likely as…
Evolution has endowed all humans with a continuum of innate, hard-wired, automatically activated defense behaviors, termed the defense cascade. Arousal is the first step in activating the defense cascade; flight or fight is an active defense response for dealing with threat; freezing is a flight-or-fight response put on hold; tonic…
This review looked at studies that measured cortisol (a stress hormone) after people visited forests, a practice called forest bathing or shinrin-yoku. The authors found that people in forest groups had lower salivary cortisol than people in urban groups, both before and after the visits. The reviewers say the change…
This randomized study tested a breathing-based meditation (Sudarshan Kriya yoga) in 21 male U.S. veterans of the Iraq or Afghanistan wars. Participants were randomly assigned to the meditation group (n = 11) or a waitlist control (n = 10). The meditation group showed reductions in self-reported PTSD symptoms, anxiety, and…
Several brain-imaging studies found that people with long-term work-related burnout showed differences in brain structure and function compared with matched healthy adults. In groups where participants had worked more than about 60–70 hours per week for several years, researchers reported larger amygdala size, thinner medial prefrontal cortex (mPFC) tissue, weaker…
The researchers repeatedly measured early-morning cortisol and self-reported depressive symptoms in a population of adolescents. Using a statistical method to find subgroups, they identified a high-risk group (17% of the sample) with both high depressive symptoms and elevated morning cortisol. Membership in this group was linked to worse autobiographical memory…
This 2022 review looks at studies linking stress, inflammation, and changes in the amygdala to depression and anxiety. It says stress can trigger inflammation in the body and brain, that inflammation can change neurons and circuits in the amygdala, and that these changes are linked to depression- and anxiety-like signs…
This 2013 review explains how physical and psychological stress change the brain and body. It describes how stress activates the HPA (hypothalamic–pituitary–adrenal) system and alters brain chemicals such as GABA, dopamine, norepinephrine and serotonin. The paper also covers short-term memory effects, animal models used to study chronic stress, and both…
Seventy-four young men walked for 15 minutes in both a forest and an urban area, with saliva taken before and after each walk. Mean salivary cortisol dropped after the forest walk (from 9.70 to 8.37 nmol/L) but hardly changed after the urban walk (from 10.28 to 10.01 nmol/L). Statistical tests…
This review looked at studies in animals and people about how stress and the balance system (the vestibular system) affect each other. In many animal experiments, vestibular damage or stimulation turns on the body's stress system (the HPA axis) and short-term stress hormones help brain circuits adjust after vestibular loss.…
This review paper brings together animal and human studies to explain how alcohol and stress hormones may change the prefrontal cortex and the body’s stress system as drinking moves from casual use toward dependence. The authors say alcohol raises stress hormones (glucocorticoids) right away, and repeated heavy use can produce…
