Post-Traumatic Stress Disorder (PTSD)

Post-traumatic stress disorder (PTSD) is a trauma- and stressor-related disorder marked by intrusive memories, avoidance, hyperarousal, and altered mood and cognition, with documented changes in brain activity and white-matter integrity.

A specific HBOT protocol has been studied as a means of inducing neuroplasticity in established, often treatment-resistant PTSD; rather than acting pharmacologically, it is proposed to drive neuroplasticity through the hyperoxic-hypoxic paradox, accompanied in trials by improved resting-state functional connectivity across the default-mode, central-executive and salience networks (2024) and increased white-matter fractional anisotropy in fronto-limbic tracts, the genu of the corpus callosum and the fornix on diffusion tensor imaging (2022).

A randomised, sham-controlled trial in 56 combat veterans (60 sessions, 90 minutes, 100% O₂ at 2 ATA) found CAPS-5 scores fell from 42.6 to 25.8 with HBOT while the sham group did not improve; an earlier randomised controlled trial in treatment-resistant PTSD showed concordant symptom and neuroimaging improvements; a 2026 systematic review and meta-analysis pooled two sham-controlled PTSD RCTs and reported a large effect while cautioning that studies are small and preliminary; and a 2026 prospective observational cohort of 50 US veterans reported reductions sustained to six months.

The investigational protocol as studied — not a clinical recommendation — comprised 60 daily sessions of 90 minutes, 100% oxygen at 2 ATA, with intermittent air breaks.

The randomised evidence originates substantially from a single research group (Sagol Center / Shamir Medical Center) — the same lineage as the Long COVID and Fibromyalgia entries — though, unlike those, there is now early independent corroboration (a US observational cohort and a meta-analysis by an unaffiliated group). Sample sizes remain small and larger multicentre randomised trials are needed. HBOT for PTSD remains investigational and is not FDA-approved.