What Researchers Did
Researchers reanalyzed data from a randomized controlled trial (RCT) of 56 male veterans with treatment-resistant PTSD who received either real HBOT or a sham treatment, to test whether achieving a certain level of improvement during treatment predicts lasting recovery three months later.
What They Found
Veterans who improved by 35% or more on PTSD symptom scores by the end of treatment continued to improve at the 3-month follow-up (p = 2×10⁻⁶), while those below this threshold did not maintain gains. Intrusive symptoms (Cluster B) showed the strongest correlation with follow-up outcomes (r = 0.74–0.80), and avoidance symptoms (Cluster C) were the best early predictor of long-term improvement.
What This Means for Canadian Patients
PTSD affects hundreds of thousands of Canadians, including veterans, first responders, and survivors of trauma, many of whom do not respond to medications or talk therapy. This study suggests that if a PTSD patient achieves at least 35% symptom improvement with HBOT, they are likely to continue improving on their own after treatment ends, a meaningful sign that HBOT may cause lasting brain-level changes. Canadian clinicians treating PTSD can use this threshold as a clinical benchmark.
Canadian Relevance
No direct Canadian connection identified.
Study Limitations
This was a post-hoc analysis of an RCT involving only male veterans, so the 35% threshold has not yet been validated in women, civilians, or other trauma populations.