Skip to content
Spiral Staircase
Buy the book
Menu

Chapter 13 of the book

Stress and the Mind

ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.3 things to start with3 popular claims graded67 works cited

How the chapter opens

At Britain's Common Cold Unit in Salisbury, volunteers came to catch colds on purpose. They lived in flats, alone or in twos and threes, and could walk the grounds as long as they stayed at least thirty feet from anyone else. Each was scored for psychological stress. Then most were given nasal drops carrying one of five cold viruses, and a few got drops of salt water.

The results climbed with the stress scores. From the least stressed to the most, the share who developed a proper cold rose from about a quarter to almost half. Smoking, drinking, exercise, diet, sleep quality and personality did not explain it. Among people already infected, stress did not make symptoms more likely. It had let more of the viruses take hold in the first place.1

What the chapter covers

The argument, the studies and the stories are in the book. Get the book.

  • ·What Your Body Expects
  • ·What It Gets Instead
  • ·When the Alarm Becomes the Problem
  • ·Calming the Alarm on Purpose

Mismatch card

The system

The stress response, fast adrenaline and slow cortisol, with the defensive emotions it drives: fear, anxiety and low mood.

What it expects

Threats that are physical, local and short, answered with the body, among allies who help solve problems.

What it gets

Uncontrollable judgment without end, low control at work, long hours, thin company and short sleep.

What happens in the gap

Alarms built to over-fire go off constantly and stop resetting; the daily cortisol rhythm flattens, tissues stop hearing it, inflammation runs on, and anxiety and low mood are common.

The handrail

Movement most days, slow breathing or a mindfulness course, trusted company and control over your hours, and treatment when symptoms persist (ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.)

Strength of evidence

ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials. Treatment effects and stress gradients rest on large trials and cohorts; the evolutionary explanations remain hypotheses, and the effect of adult stress on disease is moderate.

What you've heard

Popular claims this chapter tests, each with the book's verdict and grade.

The protocol

Each action carries the book's evidence grade. How the grades work.

Start here

  1. Move most days, in whatever form you will keep doing

    StrongEvidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.for depressive symptoms, though most trials are at high risk of bias

    How: walking or jogging, yoga, strength training or tai chi all counted in the trials. Build toward the 150 minutes a week of moderate activity that Chapter 3 sets out, and let some sessions get brisk enough to leave you breathing hard. A depressed body does not start at a runner's baseline, so begin with ten minutes out the door and build. Why: exercise produced moderate drops in depressive symptoms, and more intense sessions did somewhat more.

  2. Practice slow breathing or mindfulness for five to ten minutes a day, or take an eight-week course

    ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.

    How: breathe about six times a minute, roughly four seconds in and six out, sitting down, on most days; use a count, an app or a prayer to keep the pace. For anxiety that persists, consider an eight-week mindfulness-based stress reduction course. Why: small-to-moderate reductions in stress and anxiety in trials, and one course proved no worse than a standard drug for anxiety disorders.

  3. Talk to a clinician if low mood or anxiety lasts more than two weeks or gets in the way of work, sleep or people

    StrongEvidence grade: Strong. Multiple randomized controlled trials, or consistent large cohort studies with a well-understood mechanism.

    How: a family doctor is a fine first stop. Before the appointment, write down what you have noticed, for how long, and what it is costing you in sleep, work and time with people, because a low day in the waiting room can make a hard month sound like nothing. Ask about the options, including talking therapy; if cost or a waiting list is the barrier, say so and ask about lower-cost and online options. Why: every antidepressant tested beat placebo; the wrong chemical story never meant the treatment was wrong. If you already take a psychiatric medicine, keep taking it; any change belongs in a conversation with the person who prescribed it.

When to get help now

If you have thoughts of suicide or self-harm, or feel unsafe, do not wait two weeks. In the US, call or text 988, the Suicide and Crisis Lifeline; elsewhere, call your local emergency number or go to an emergency department.26 Chest pain, breathlessness or collapse during intense emotion is a medical emergency too.

Then, pick from this menu

  • **Bring a trusted person to the hard thing, not just the debrief (ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.).** How: ask someone to wait with you before the appointment or sit with you while you prepare for the interview. Why: among volunteers exposed to a cold virus, feeling supported blunted the extra risk that came with frequent conflict, and a best friend present while men prepared for the Trier test suppressed their cortisol response, a calming effect seen across species.27 Chapter 11 covers building the circle.

  • **Buy back control over your hours (ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.).** How: fixed start and finish times, a say in how your work gets done, and fewer weeks of fifty-five hours or more count as stress interventions even when the workload stays the same. Why: low control at work explained much of the civil-service gradient, and very long weeks went with about a third more strokes. If the job cannot change, start by fixing a time when work messages stop.

  • **Protect the night (EmergingEvidence grade: Emerging. Early, small, animal-only, or actively contested. for stress hormones).** A short night raised the next evening's cortisol by more than a third, and a sleepless one by nearly half, in a small laboratory study of young men.28 Chapter 8 holds the sleep program.

  • **Spend time somewhere green (EmergingEvidence grade: Emerging. Early, small, animal-only, or actively contested. for stress).** A park settles the alarm on its own timetable, not instantly (Chapter 10).

  • **Keep a sigh for a quick reset (EmergingEvidence grade: Emerging. Early, small, animal-only, or actively contested.).** Inhale slowly through the nose, top up with a second short inhale, then breathe out slowly through the mouth, for a minute or up to five.

  • **Skip adrenal supplements and saliva-cortisol kits (ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.).** Put the money toward a doctor's visit if you are exhausted.

If this is you

Perimenopause

tell your clinician about mood and sleep, not only hot flushes, even if you have never been depressed (Chapter 15).

Pregnant, or with a new baby

about one mother in eight to one in six has depression around pregnancy or after birth. Line up specific people and specific help before the birth, and raise low mood early (Chapter 15).29

Caring for a parent, partner or young children

this is the long, uncontrollable kind of strain. Fit your ten minutes of movement to something that already happens every day, such as the school drop-off, and bring one trusted person into the hardest part of the week (Chapter 11).

A child being assessed for ADHD

if your child was among the youngest in the class, mention it. It is one more piece of information, not a reason to dismiss the diagnosis.

An adult with ADHD weighing medication

given the registry findings, discuss it on its merits, not as a last resort.

Over 50, or stiff joints

yoga, tai chi and strength training all counted in the depression trials.

Short on time or money

ten minutes of walking and a few of slow breathing cost nothing, and can be done together. Free guided recordings are enough to keep the pace.

Night shifts

keep your hours as regular as the rota allows; Chapter 8 has the shift-work program.

Safety

Do slow breathing sitting or lying down. Never practice fast breathing or breath-holds in or near water, in the bath or while driving, where they can cause blackout and drowning; skip them if you are pregnant or have heart disease or a seizure disorder, and stop if you feel dizzy. In the sighing trial, about one participant in ten reported a negative experience; stop any drill that makes you feel worse.30 With heart disease or chest pain on exertion, get medical advice before training hard. Never stop an antidepressant or ADHD medicine suddenly without your prescriber. This chapter is not a substitute for assessment and treatment.

The skeptic's box

What could overturn this chapter, from the chapter itself.

Evolutionary psychiatry has a testability problem. The three stories about depression were fitted to observations after the fact, and such stories are cheap to build and expensive to test. The hunter-in-the-classroom evidence rests on one gene study, one online game and one natural experiment in diagnosis rates, and none of it shows ADHD traits helped most ancient foragers. The exercise trials cannot be blinded, so the size of the benefit is uncertain, though not its direction. The serotonin review drew published rebuttals of its methods, and neither side's argument bears on whether the drugs beat placebo. The stress-and-heart links are mostly observational, and the stress-to-disease effect in adults is moderate. Large, preregistered trials tracking depression or heart disease for years would show what breathing and mindfulness are worth.

Go deeper in the reference library

The research this chapter was built from, as longer reference entries: each with its own mismatch card, graded recommendations and the case against it.

See also in the book

Sources behind this page

  1. 1.Cohen, S. (2021). "Psychosocial vulnerabilities to upper respiratory infectious illness: implications for susceptibility to coronavirus disease 2019 (COVID-19)." Perspectives on Psychological Science, 16(1), 161-174. https://doi.org/10.1177/1745691620942516 (Describes the Salisbury flats.) ; Cohen, S., Tyrrell, D.A., and Smith, A.P. (1991). "Psychological stress and susceptibility to the common cold." New England Journal of Medicine, 325(9), 606-612. https://doi.org/10.1056/NEJM199108293250903 (394 volunteers given one of five viruses, 26 given saline; infection rose from about 74% to 90% and clinical colds from about 27% to 47%, attributable "to increased rates of infection rather than to an increased frequency of symptoms after infection.")
  2. 12.Cadegiani, F.A., and Kater, C.E. (2016). "Adrenal fatigue does not exist: a systematic review." BMC Endocrine Disorders, 16(1), 48. https://doi.org/10.1186/s12902-016-0128-4 (58 studies.) ; Endocrine Society (2022). "Adrenal Fatigue." https://www.endocrine.org/patient-engagement/endocrine-library/adrenal-fatigue (Page last updated 25 January 2022; read September 2026.)
  3. 24.Balban, M.Y., Neri, E., Kogon, M.M., Weed, L., et al. (2023). "Brief structured respiration practices enhance mood and reduce physiological arousal." Cell Reports Medicine, 4(1), 100895. https://doi.org/10.1016/j.xcrm.2022.100895 (108 participants, mostly undergraduates; run June to September 2020 and registered retrospectively in March 2022, NCT05304000; instructional videos pre-recorded by one of the authors.)
  4. 25.Fincham, G.W., Strauss, C., Montero-Marin, J., and Cavanagh, K. (2023). "Effect of breathwork on stress and mental health: a meta-analysis of randomised-controlled trials." Scientific Reports, 13(1), 432. https://doi.org/10.1038/s41598-022-27247-y (12 trials and 785 adults for stress, effect -0.35; anxiety -0.32; depressive symptoms -0.40.)
  5. 29.Woody, C.A., Ferrari, A.J., Siskind, D.J., Whiteford, H.A., et al. (2017). "A systematic review and meta-regression of the prevalence and incidence of perinatal depression." Journal of Affective Disorders, 219, 86-92. https://doi.org/10.1016/j.jad.2017.05.003 (Pooled perinatal prevalence 11.9%.) ; Wang, Z., Liu, J., Shuai, H., Cai, Z., et al. (2021). "Mapping global prevalence of depression among postpartum women." Translational Psychiatry, 11(1), 543. https://doi.org/10.1038/s41398-021-01663-6 (17.22% across 565 studies, lower in high-income countries.)
  6. 30.Boyd, C., Levy, A., McProud, T., Huang, L., et al. (2015). "Fatal and nonfatal drowning outcomes related to dangerous underwater breath-holding behaviors: New York State, 1988-2011." MMWR Morbidity and Mortality Weekly Report, 64(19), 518-521. https://pmc.ncbi.nlm.nih.gov/articles/PMC4584570/ ; Ainslie, P.N., and Duffin, J. (2009). "Integration of cerebrovascular CO2 reactivity and chemoreflex control of breathing: mechanisms of regulation, measurement, and interpretation." American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, 296(5), R1473-R1495. https://doi.org/10.1152/ajpregu.91008.2008 (Low carbon dioxide from fast breathing narrows the brain's blood vessels.) ; Wim Hof Method (2026). What Is Shallow Water Blackout? https://www.wimhofmethod.com/what-is-shallow-water-blackout (Advises against deep-breathing practice in or over water or "when piloting a vehicle.") ; Balban et al. (2023), note 23 (10% of participants reported negative experiences).
  7. 26.988 Suicide and Crisis Lifeline. https://988lifeline.org (Call, text or chat in the US; checked September 2026.)
  8. 27.Cohen, S., Janicki-Deverts, D., Turner, R.B., and Doyle, W.J. (2015). "Does hugging provide stress-buffering social support? A study of susceptibility to upper respiratory infection and illness." Psychological Science, 26(2), 135-147. https://doi.org/10.1177/0956797614559284 (404 adults; hugs, self-reported rather than assigned, accounted for about a third of the protective effect of support.) ; Heinrichs, M., Baumgartner, T., Kirschbaum, C., and Ehlert, U. (2003). "Social support and oxytocin interact to suppress cortisol and subjective responses to psychosocial stress." Biological Psychiatry, 54(12), 1389-1398. https://doi.org/10.1016/S0006-3223(03)00465-7 (37 healthy men.) ; Hostinar, C.E., Sullivan, R.M., and Gunnar, M.R. (2014). "Psychobiological mechanisms underlying the social buffering of the hypothalamic-pituitary-adrenocortical axis: a review of animal models and human studies across development." Psychological Bulletin, 140(1), 256-282. https://doi.org/10.1037/a0032671
  9. 28.Leproult, R., Copinschi, G., Buxton, O., and Van Cauter, E. (1997). "Sleep loss results in an elevation of cortisol levels the next evening." Sleep, 20(10), 865-870. https://pubmed.ncbi.nlm.nih.gov/9415946/ (Evening cortisol 37% higher after partial and 45% higher after total sleep deprivation.)

Every work this chapter cites

The chapter's 30 notes cite 67 works, listed by note number. Each is also in the full source register.

  1. 1.Cohen, S (2021). Psychosocial vulnerabilities to upper respiratory infectious illness: implications for susceptibility to coronavirus disease 2019 (COVID-19). Perspectives on Psychological Science. 10.1177/1745691620942516Cohen, S., Tyrrell, D.A., and Smith, A.P (1991). Psychological stress and susceptibility to the common cold. New England Journal of Medicine. 10.1056/NEJM199108293250903
  2. 2.Cohen, S., Frank, E., Doyle, W.J., Skoner, D.P., Rabin, B.S., and Gwaltney, J.M (1998). Types of stressors that increase susceptibility to the common cold in healthy adults. Health Psychology. 10.1037/0278-6133.17.3.214Cohen, S., Janicki-Deverts, D., Doyle, W.J., Miller, G.E., Frank, E., Rabin, B.S., and Turner, R.B (2012). Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk. PNAS. 10.1073/pnas.1118355109Cohen (2021). , note 1, describes the Pittsburgh hotel-room quarantine.
  3. 3.Cannon, W.B (1915). Bodily Changes in Pain, Hunger, Fear and Rage: An Account of Recent Researches into the Function of Emotional Excitement. archive.orgSmith, S.M., and Vale, W.W (2006). The role of the hypothalamic-pituitary-adrenal axis in neuroendocrine responses to stress. Dialogues in Clinical Neuroscience. 10.31887/DCNS.2006.8.4/ssmithSapolsky, R.M., Romero, L.M., and Munck, A.U (2000). How do glucocorticoids influence stress responses? Integrating permissive, suppressive, stimulatory, and preparative actions. Endocrine Reviews. 10.1210/edrv.21.1.0389
  4. 4.Nesse, R.M (2005). Natural selection and the regulation of defenses: a signal detection analysis of the smoke detector principle. Evolution and Human Behavior. 10.1016/j.evolhumbehav.2004.08.002Nesse, R.M (2019). The smoke detector principle: signal detection and optimal defense regulation. Evolution, Medicine, and Public Health. 10.1093/emph/eoy034
  5. 5.Sloman, L., and Gilbert, P. (Eds.) (2000). Subordination and Defeat: An Evolutionary Approach to Mood Disorders and Their Therapy. Andrews, P.W., and Thomson, J.A (2009). The bright side of being blue: depression as an adaptation for analyzing complex problems. Psychological Review. 10.1037/a0016242Raison, C.L., and Miller, A.H (2013). The evolutionary significance of depression in Pathogen Host Defense (PATHOS-D). Molecular Psychiatry. 10.1038/mp.2012.2
  6. 6.Goudarzi, S (2007). Why Humans (and Baboons) Stress So Much. Live Science. livescience.com
  7. 7.Dickerson, S.S., and Kemeny, M.E (2004). Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research. Psychological Bulletin. 10.1037/0033-2909.130.3.355Birkett, M.A (2011). The Trier Social Stress Test protocol for inducing psychological stress. Journal of Visualized Experiments. 10.3791/3238
  8. 8.Marmot, M.G., Rose, G., Shipley, M., and Hamilton, P.J (1978). Employment grade and coronary heart disease in British civil servants. Journal of Epidemiology and Community Health. 10.1136/jech.32.4.244Marmot, M.G., Smith, G.D., Stansfeld, S., Patel, C., et al (1991). Health inequalities among British civil servants: the Whitehall II study. The Lancet. 10.1016/0140-6736(91Marmot, M.G., Bosma, H., Hemingway, H., Brunner, E., and Stansfeld, S (1997). Contribution of job control and other risk factors to social variations in coronary heart disease incidence. The Lancet. 10.1016/S0140-6736(97
  9. 9.Sapolsky, R.M., and Share, L.J (2004). A pacific culture among wild baboons: its emergence and transmission. PLoS Biology. 10.1371/journal.pbio.0020106Sapolsky, R.M (2005). The influence of social hierarchy on primate health. Science. 10.1126/science.1106477
  10. 10.Kivimäki, M., Nyberg, S.T., Batty, G.D., Fransson, E.I., et al (2012). Job strain as a risk factor for coronary heart disease: a collaborative meta-analysis of individual participant data. The Lancet. 10.1016/S0140-6736(12Kivimäki, M., Jokela, M., Nyberg, S.T., Singh-Manoux, A., et al (2015). Long working hours and risk of coronary heart disease and stroke: a systematic review and meta-analysis of published and unpublished data for 603,838 individuals. The Lancet. 10.1016/S0140-6736(15Kivimäki, M., and Steptoe, A (2018). Effects of stress on the development and progression of cardiovascular disease. Nature Reviews Cardiology. 10.1038/nrcardio.2017.189Leor, J., Poole, W.K., and Kloner, R.A (1996). Sudden cardiac death triggered by an earthquake. New England Journal of Medicine. 10.1056/NEJM199602153340701
  11. 11.Kumari, M., Shipley, M., Stafford, M., and Kivimaki, M (2011). Association of diurnal patterns in salivary cortisol with all-cause and cardiovascular mortality: findings from the Whitehall II study. Journal of Clinical Endocrinology and Metabolism. 10.1210/jc.2010-2137Adam, E.K., Quinn, M.E., Tavernier, R., McQuillan, M.T., et al (2017). Diurnal cortisol slopes and mental and physical health outcomes: a systematic review and meta-analysis. Psychoneuroendocrinology. 10.1016/j.psyneuen.2017.05.018Kiecolt-Glaser, J.K., Marucha, P.T., Malarkey, W.B., Mercado, A.M., and Glaser, R (1995). Slowing of wound healing by psychological stress. The Lancet. 10.1016/S0140-6736(95Marucha, P.T., Kiecolt-Glaser, J.K., and Favagehi, M (1998). Mucosal wound healing is impaired by examination stress. Psychosomatic Medicine. 10.1097/00006842-199805000-00025
  12. 12.Cadegiani, F.A., and Kater, C.E (2016). Adrenal fatigue does not exist: a systematic review. BMC Endocrine Disorders. 10.1186/s12902-016-0128-4Endocrine Society (2022). Adrenal Fatigue. endocrine.org
  13. 13.World Health Organization (2026). Anxiety disorders. who.int
  14. 14.Hidaka, B.H (2012). Depression as a disease of modernity: explanations for increasing prevalence. Journal of Affective Disorders. 10.1016/j.jad.2011.12.036
  15. 15.Salk, R.H., Hyde, J.S., and Abramson, L.Y (2017). Gender differences in depression in representative national samples: meta-analyses of diagnoses and symptoms. Psychological Bulletin. 10.1037/bul0000102McLean, C.P., Asnaani, A., Litz, B.T., and Hofmann, S.G (2011). Gender differences in anxiety disorders: prevalence, course of illness, comorbidity and burden of illness. Journal of Psychiatric Research. 10.1016/j.jpsychires.2011.03.006Freeman, E.W., Sammel, M.D., Lin, H., and Nelson, D.B (2006). Associations of hormones and menopausal status with depressed mood in women with no history of depression. Archives of General Psychiatry. 10.1001/archpsyc.63.4.375Robertson, E., Grace, S., Wallington, T., and Stewart, D.E (2004). Antenatal risk factors for postpartum depression: a synthesis of recent literature. General Hospital Psychiatry. 10.1016/j.genhosppsych.2004.02.006Liu, J.J.W., Ein, N., Peck, K., Huang, V., Pruessner, J.C., and Vickers, K (2017). Sex differences in salivary cortisol reactivity to the Trier Social Stress Test (TSST): a meta-analysis. Psychoneuroendocrinology. 10.1016/j.psyneuen.2017.04.007Kuehner, C (2017). Why is depression more common among women than among men? Lancet Psychiatry. 10.1016/S2215-0366(16
  16. 16.Moncrieff, J., Cooper, R.E., Stockmann, T., Amendola, S., et al (2022). The serotonin theory of depression: a systematic umbrella review of the evidence. Molecular Psychiatry. 10.1038/s41380-022-01661-0
  17. 17.Cipriani, A., Furukawa, T.A., Salanti, G., Chaimani, A., et al (2018). Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis. The Lancet. 10.1016/S0140-6736(17
  18. 18.Noetel, M., Sanders, T., Gallardo-Gómez, D., Taylor, P., et al (2024). Effect of exercise for depression: systematic review and network meta-analysis of randomised controlled trials. BMJ. 10.1136/bmj-2023-075847Singh, B., Olds, T., Curtis, R., Dumuid, D., et al (2023). Effectiveness of physical activity interventions for improving depression, anxiety and distress: an overview of systematic reviews. British Journal of Sports Medicine. 10.1136/bjsports-2022-106195
  19. 19.Goyal, M., Singh, S., Sibinga, E.M., Gould, N.F., et al (2014). Meditation programs for psychological stress and well-being: a systematic review and meta-analysis. JAMA Internal Medicine. 10.1001/jamainternmed.2013.13018Hoge, E.A., Bui, E., Mete, M., Dutton, M.A., Baker, A.W., and Simon, N.M (2023). Mindfulness-based stress reduction vs escitalopram for the treatment of adults with anxiety disorders: a randomized clinical trial. JAMA Psychiatry. 10.1001/jamapsychiatry.2022.3679
  20. 20.Faraone, S.V., Banaschewski, T., Coghill, D., Zheng, Y., et al (2021). The World Federation of ADHD International Consensus Statement: 208 evidence-based conclusions about the disorder. Neuroscience and Biobehavioral Reviews. 10.1016/j.neubiorev.2021.01.022Eisenberg, D.T.A., Campbell, B., Gray, P.B., and Sorenson, M.D (2008). Dopamine receptor genetic polymorphisms and body composition in undernourished pastoralists: an exploration of nutrition indices among nomadic and recently settled Ariaal men of northern Kenya. BMC Evolutionary Biology. 10.1186/1471-2148-8-173Barack, D.L., Ludwig, V.U., Parodi, F., Ahmed, N., et al (2024). Attention deficits linked with proclivity to explore while foraging. Proceedings of the Royal Society B. 10.1098/rspb.2022.2584
  21. 21.Layton, T.J., Barnett, M.L., Hicks, T.R., and Jena, A.B (2018). Attention deficit-hyperactivity disorder and month of school enrollment. New England Journal of Medicine. 10.1056/NEJMoa1806828
  22. 22.Li, L., Zhu, N., Zhang, L., Kuja-Halkola, R., et al (2024). ADHD pharmacotherapy and mortality in individuals with ADHD. JAMA. 10.1001/jama.2024.0851Lichtenstein, P., Halldner, L., Zetterqvist, J., Sjölander, A., et al (2012). Medication for attention deficit-hyperactivity disorder and criminality. New England Journal of Medicine. 10.1056/NEJMoa1203241
  23. 23.Bernardi, L., Sleight, P., Bandinelli, G., Cencetti, S., et al (2001). Effect of rosary prayer and yoga mantras on autonomic cardiovascular rhythms: comparative study. BMJ. 10.1136/bmj.323.7327.1446Laborde, S., Allen, M.S., Borges, U., Dosseville, F., et al (2022). Effects of voluntary slow breathing on heart rate and heart rate variability: a systematic review and a meta-analysis. Neuroscience and Biobehavioral Reviews. 10.1016/j.neubiorev.2022.104711Goessl, V.C., Curtiss, J.E., and Hofmann, S.G (2017). The effect of heart rate variability biofeedback training on stress and anxiety: a meta-analysis. Psychological Medicine. 10.1017/S0033291717001003
  24. 24.Balban, M.Y., Neri, E., Kogon, M.M., Weed, L., et al (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine. 10.1016/j.xcrm.2022.100895
  25. 25.Fincham, G.W., Strauss, C., Montero-Marin, J., and Cavanagh, K (2023). Effect of breathwork on stress and mental health: a meta-analysis of randomised-controlled trials. Scientific Reports. 10.1038/s41598-022-27247-y
  26. 26.988 Suicide and Crisis Lifeline. 988lifeline.org
  27. 27.Cohen, S., Janicki-Deverts, D., Turner, R.B., and Doyle, W.J (2015). Does hugging provide stress-buffering social support? A study of susceptibility to upper respiratory infection and illness. Psychological Science. 10.1177/0956797614559284Heinrichs, M., Baumgartner, T., Kirschbaum, C., and Ehlert, U (2003). Social support and oxytocin interact to suppress cortisol and subjective responses to psychosocial stress. Biological Psychiatry. 10.1016/S0006-3223(03Hostinar, C.E., Sullivan, R.M., and Gunnar, M.R (2014). Psychobiological mechanisms underlying the social buffering of the hypothalamic-pituitary-adrenocortical axis: a review of animal models and human studies across development. Psychological Bulletin. 10.1037/a0032671
  28. 28.Leproult, R., Copinschi, G., Buxton, O., and Van Cauter, E (1997). Sleep loss results in an elevation of cortisol levels the next evening. Sleep. pubmed.ncbi.nlm.nih.gov
  29. 29.Woody, C.A., Ferrari, A.J., Siskind, D.J., Whiteford, H.A., et al (2017). A systematic review and meta-regression of the prevalence and incidence of perinatal depression. Journal of Affective Disorders. 10.1016/j.jad.2017.05.003Wang, Z., Liu, J., Shuai, H., Cai, Z., et al (2021). Mapping global prevalence of depression among postpartum women. Translational Psychiatry. 10.1038/s41398-021-01663-6
  30. 30.Boyd, C., Levy, A., McProud, T., Huang, L., et al (2015). Fatal and nonfatal drowning outcomes related to dangerous underwater breath-holding behaviors: New York State, 1988-2011. MMWR Morbidity and Mortality Weekly Report. pmc.ncbi.nlm.nih.govAinslie, P.N., and Duffin, J (2009). Integration of cerebrovascular CO2 reactivity and chemoreflex control of breathing: mechanisms of regulation, measurement, and interpretation. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology. 10.1152/ajpregu.91008.2008Wim Hof Method (2026). What Is Shallow Water Blackout? wimhofmethod.comBalban et al (2023). , note 23 (10% of participants reported negative experiences).

The full source register

This page carries the chapter's apparatus. The chapter itself, and the fifteen others, are in the book.

Get the bookThe 30-day protocolAll sixteen chapters