What Chronic Stress Does to Your Brain, and a Five Minute Breathing Practice Worth Trying

Checked against primary sources by the Editorial Team. Every figure in this article was traced to the study it came from, including the ones that contradict what we previously published. How we review.

Chronic stress feels like a mood problem. Researchers who study it describe something wider: a body that stays on alert, and a brain that adapts to that alert state. Here is what the research literature says, how far it goes, and what one small trial found when it tested a short daily breathing practice.

What researchers report about stress and the brain

Sonia Lupien, Bruce McEwen, Megan Gunnar, and Christine Heim reviewed how stress hormone exposure affects the brain across the lifespan. They describe stress linked to memory problems and reduced hippocampal volume, particularly in aging. The hippocampus is a region involved in forming memories.

The same review describes stress causing dendritic hypertrophy, an increase in the branching of neurons, in the amygdala. The amygdala helps detect threat. The authors connect this to heightened anxiety responses.

Amy Arnsten reviewed how stress affects the prefrontal cortex, the region behind planning, focus, and impulse control. She reports that even mild, acute, uncontrollable stress can rapidly impair prefrontal cognitive abilities, and that prolonged stress leads to structural changes in prefrontal neurons while strengthening amygdala function.

What these reviews do not say

A few cautions matter here. Much of the structural evidence in these reviews comes from animal studies, and the authors discuss different effects at different life stages. A previous version of this article stated that chronic stress shrinks the hippocampus, enlarges the amygdala through high cortisol, and suppresses prefrontal activity, as if all of that were settled for every adult. The reviews support a more careful version: stress is linked to these changes, the details depend on timing and duration, and the findings are not a diagnosis for any one person.

None of this means your brain is damaged. The authors describe processes that can shift with context, which is the reason researchers test interventions at all.

The trial behind the five minute claim

The most cited recent test of short breathing practices is a randomized trial by Melis Yilmaz Balban, David Spiegel, Andrew Huberman, and colleagues, published in Cell Reports Medicine in January 2023. The authors enrolled 108 people, and 100 completed the study. Participants were assigned to one of four daily five minute practices for 28 days, delivered remotely: mindfulness meditation, cyclic sighing, box breathing, or cyclic hyperventilation with retention.

Cyclic sighing means a double inhale through the nose, a shallow one followed by a deeper one, then a long, slow exhale through the mouth.

The authors report that all groups improved. Breathwork produced a greater improvement in mood than meditation, and cyclic sighing showed the largest gains in positive affect, which grew with how consistently people practiced. Both breathwork and meditation reduced state anxiety and negative affect.

Where our earlier version went too far

We previously wrote that cyclic sighing beat mindfulness meditation, box breathing, and unguided relaxation at reducing anxiety. The paper does not say that. Mindfulness meditation was the comparison group. Box breathing was another breathing arm, and no unguided relaxation arm appears in the study design we read. The mood advantage belonged to breathwork overall, with cyclic sighing strongest for positive affect. On anxiety, both approaches helped.

Limits the authors acknowledge

• Group sizes were small, which limits the power to compare one practice against another. Only 24 completers were in the meditation group.
• The study ran remotely, so the researchers had less control over how people did the exercises.
• Follow up ran for four weeks, with no long term data.
• Adherence relied on self report.
• The participants were mostly undergraduates, so the findings may not carry over to a stressed 50 year old.

The trial also did not test whether five minutes is better than two or twenty. It used five minutes. It did not show that five minutes is the minimum that works, or the best amount.

How the wider evidence looks

Guy Fincham, Clara Strauss, Jesus Montero Marin, and Kate Cavanagh pooled randomized trials of breathwork in Scientific Reports in 2023. For stress, their main outcome, they analyzed 12 trials with 785 adults and report a small to medium effect (effect size g of minus 0.35). They also report small to moderate reductions in anxiety and depression across more studies. They note that most trials carried a moderate risk of bias, and they warn of a miscalibration between hype and evidence.

Mindfulness has a larger research base. Madhav Goyal and colleagues reviewed 47 randomized trials with 3,515 participants in JAMA Internal Medicine in 2014. They report moderate evidence that mindfulness meditation programs improve anxiety and depression, and low evidence for stress and distress compared with active controls. They also report that meditation was not better than established treatments such as drugs or exercise. Those programs were typically structured courses, not five minute daily sessions.

Taken together, the authors support a modest claim. Slow, structured breathing and mindfulness both appear to help some people feel better, and the effects are small to moderate.

A reasonable way to act on this

Based on those findings, one way to act on them is to try the breathing practice the Balban trial used and see how you feel after a few weeks. It costs nothing, it needs no equipment, and the authors report improvements in mood in the group that practiced it. If you prefer silence and attention training, the mindfulness research gives you a reason to try that instead. The Balban participants who did meditation improved as well.

If stress stays heavy for weeks despite a daily practice, or it interferes with sleep, work, or relationships, a daily breathing habit is not meant to carry that load alone. That is a good time to talk with a doctor or a licensed therapist. If you are in crisis, call or text 988.