Slow breathing / device-guided breathing (DGB)
Introduced with the Weng et al. (2021) ingest, and notable for being the wiki’s first body-directed intervention that does not go through awareness at all.
Every other intervention in the applications and methods folders — mindfulness-meditation, interoceptive-exposure, mabt, somatic-experiencing — changes how a person attends to, appraises or tolerates bodily sensation. bioelectronic-medicine bypasses the person entirely by putting current into a nerve. Slow breathing sits in between and is the awkward case: the person performs it voluntarily, but the mechanism as stated is pure reflex physiology, and nothing in it requires them to notice a single sensation.
The mechanism as given
Rate down (~5 breaths/min) → tidal volume up → cardiopulmonary stretch receptors activated → reflex reduction in sympathetic nervous system activation → blood pressure down. Slow breathing additionally improves arterial baroreflex control of SNS activity.
The clinical rationale is sympathetic overactivity, which characterizes chronic kidney disease and PTSD, both of which carry elevated cardiovascular risk, and for which the drug options are poorly tolerated.
The evidence, as reviewed
- DGB acutely reduced blood pressure and muscle sympathetic nerve activity (MSNA) and improved arterial baroreflex sensitivity in veterans with PTSD (Fonkoue et al. 2018) — a group with documented augmented SNS reactivity to mental stress and impaired baroreflex sensitivity (Park et al. 2017).
- 8 weeks of daily DGB reduced sympathetic reactivity to mental stress in PTSD patients (Fonkoue et al. 2020) — the only durable-exposure result here.
- Slow breathing improves baroreflex sensitivity in chronic heart failure (Bernardi et al. 2002) and essential hypertension (Joseph et al. 2005).
- An RCT of mindfulness-based stretching with deep breathing reduced PTSD symptom severity in women with subclinical PTSD (Kim et al. 2013) — with the review’s own caveat that “the exact interoceptive mechanisms are unclear.”
The comparison that matters
In CKD patients, a single mindfulness session including breathing awareness lowered MSNA and blood pressure versus a health-education control; the meditation also lowered respiratory rate, but slow breathing alone did not produce the same reductions (Park et al. 2014).
This is the wiki’s only direct test separating the respiratory manipulation from the attentional one, and it comes out against the manipulation. One study, single session, small sample — but it is exactly the design the wiki has been asking for elsewhere (see the trans-therapeutic null on mindfulness-interoceptive-training), and it cuts the opposite way. Both results are now recorded side by side.
Is this interoception?
Worth asking plainly, because the review files it under interoceptive interventions and the wiki should not simply inherit that. The case for: it manipulates an interoceptive channel, it works via interoceptive afferents (stretch receptors, baroreceptors), and it changes an interoceptive system’s state. The case against: no interoceptive representation, attention, appraisal or awareness is involved or measured; by the same standard, exercise and antihypertensives are interoceptive interventions.
The wiki records it as a manipulation of an interoceptive pathway rather than of interoception — the same distinction drawn on bioelectronic-medicine, and the reason respiratory-interoception exists as a page.
The unmeasured dose (added with the Allen 2026 ingest)
“Device-paced delivery makes dose and adherence unusually well defined” is listed above as a strength, and on inspection it is an assumption rather than a measurement. The pacer defines the prescribed dose. Nothing in any study here records what the participant’s chest actually did — whether they hit 5 breaths/min or drifted to 8, whether tidal volume rose as the mechanism requires, whether compliance decayed over an 8-week home-practice protocol where nobody is watching.
This matters because the mechanism is specific about the physiology: rate down → tidal volume up → stretch receptors → sympathetic withdrawal. If a participant slows their rate without deepening the breath, the causal chain never starts, and they would be scored as fully dosed.
respyra (Allen 2026) supplies the missing instrument almost incidentally: it scores continuous tracking error against a prescribed sinusoidal target at exactly the frequency this literature uses (0.1 Hz / 6 breaths per minute), and logs depth alongside rate. Allen names this application himself — quantifying “how accurately individuals can implement prescribed breathing patterns.”
Two consequences if it were used:
- Fidelity becomes a covariate rather than an assumption. Non-response in a slow-breathing trial currently cannot be distinguished from non-compliance.
- The Park et al. (2014) comparison becomes interpretable. That result — mindfulness lowered MSNA and blood pressure while slow breathing alone did not, though the meditation also slowed breathing — is the wiki’s only direct separation of the respiratory manipulation from the attentional one, and it cuts against the manipulation. But with no fidelity measure, “slow breathing alone did not work” and “the slow-breathing group did not slow their breathing as well as the meditators did” are indistinguishable readings of the same null. Held open.