The science

The Library

The practices at Halcyon are old. The research on them is newer, and growing. These are the studies we read and return to, each with a short note in plain language and a link to the original paper. We share them to inform, not to promise, and none of it is medical advice.

5 studies

Breathwork

Breathwork Interventions for Adults with Clinically Diagnosed Anxiety Disorders: A Scoping Review

Banushi B, Brendle M, Ragnhildstveit A, et al.

Brain Sciences · 2023

This scoping review looked for clinical studies that used breathwork on its own, without other treatments, for adults formally diagnosed with an anxiety disorder under DSM-5 criteria. From 1,081 articles found in three databases, 16 studies were included. Across a range of breathing techniques, the studies reported meaningful improvements in anxiety symptoms. The authors note that dysfunctional breathing is a hallmark of anxiety, yet standard treatments rarely address it, and they discuss protocols that are feasible and accessible for patients. Results on the role of hyperventilation were contradictory in a few studies. As a scoping review, it maps the available research rather than pooling results statistically or rating study quality in depth, so it shows where evidence exists more than how strong it is.

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Breathwork

The Effect of Diaphragmatic Breathing on Attention, Negative Affect and Stress in Healthy Adults

Ma X, Yue ZQ, Gong ZQ, et al.

Frontiers in Psychology · 2017

Forty healthy adults were randomly assigned either to a diaphragmatic breathing program or to a control group that did not receive the training. The breathing group completed 20 sessions over eight weeks, using a real-time feedback device and breathing at about four breaths per minute. Everyone completed attention and mood tests before and after, and gave saliva samples to measure cortisol, a stress hormone. After training, the breathing group showed less negative affect, better sustained attention, and lower cortisol levels, while the control group showed no change in cortisol. The authors see diaphragmatic breathing as a mind-body practice with value for health promotion in healthy people. Limitations: the sample was small, and the control group received no alternative activity, so some of the benefit could come from attention or expectation rather than the breathing itself.

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Breathwork · Consciousness

How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing

Zaccaro A, Piarulli A, Laurino M, et al.

Frontiers in Human Neuroscience · 2018

This systematic review asked what actually happens in the body and brain when healthy people slow their breathing to fewer than ten breaths per minute. From 2,461 abstracts, 15 studies met the criteria. Across them, slow breathing was linked with higher heart rate variability, a marker of parasympathetic (rest and digest) activity, along with shifts in brain activity such as more alpha and less theta power on EEG. People also reported feeling more comfortable, relaxed, pleasant, vigorous and alert, with less anxiety, anger and confusion. The authors propose two possible mechanisms, one involving awareness of internal body states and one involving nasal breathing and the olfactory system. A clear limitation is the small evidence base: only 15 studies qualified, and the brain imaging findings rest on a single fMRI study.

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Breathwork

Effect of breathwork on stress and mental health: A meta-analysis of randomised-controlled trials

Fincham GW, Strauss C, Montero-Marin J, et al.

Scientific Reports · 2023

This meta-analysis pooled randomised controlled trials that compared breathwork, meaning deliberate control of the breath, with non-breathwork control conditions. For the main outcome, self-reported stress, the authors combined 12 trials with 785 adults. Breathwork was associated with lower stress than control conditions, a small-to-medium effect. Secondary analyses of anxiety (20 trials) and depressive symptoms (18 trials) showed effects of a similar size. The authors conclude that breathwork may help with stress and mental health, but they explicitly urge caution so that public enthusiasm does not run ahead of the evidence. The honest limitation is in the studies themselves: most were judged to be at moderate risk of bias, and results varied between trials, so better-designed research is still needed.

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Breathwork · Meditation

Brief structured respiration practices enhance mood and reduce physiological arousal

Balban MY, Neri E, Kogon MM, et al.

Cell Reports Medicine · 2023

Researchers at Stanford ran a remote randomized controlled trial comparing three daily five-minute breathing exercises with five minutes of mindfulness meditation, practiced every day for one month. The breathing styles were cyclic sighing, which stretches out the exhale; box breathing, with equal inhale, hold and exhale; and cyclic hyperventilation with breath retention. The team tracked mood, anxiety and physiological arousal, including breathing rate, heart rate and heart rate variability. Breathwork overall, and especially exhale-focused cyclic sighing, produced a greater improvement in mood and a larger drop in resting breathing rate than mindfulness meditation. The authors describe daily cyclic sighing as a promising stress management exercise. One honest limitation: the abstract reports the comparison against meditation rather than against a no-practice group, and the study ran for a single month, so longer-term effects remain open.

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