Researchers led by Shai Efrati of Tel Aviv University have conducted small clinical trials that have shown that hyperbaric oxygen therapy can significantly reduce the symptoms of post-traumatic stress disorder (PTSD) in combat veterans. The double-blind, randomized, controlled trials of HBOT involved 56 veterans with a diagnosis of PTSD. Half of them received 90 minutes of hyperbaric oxygen therapy with 100 percent oxygen (with five-minute breaks for normal air every 20 minutes) and a pressure of two atmospheres five days a week (60 sessions in total), while the other half were in an oxygenator with a normal oxygen concentration and pressure (increased to 1.2 atmospheres during the first five minutes of the session). The results were published in The Journal of Clinical Psychiatry.
It was found that with the active intervention, the severity of PTSD symptoms according to the CAPS-5 scale decreased on average from 42.57 ± 9.29 at baseline to 25.8 ± 9.5 at the end of treatment (p < 0.001) and 25.08 ± 13.08 (p < 0.001) at the follow-up examination after 1–4 weeks. At the same time, with placebo procedures, this indicator increased from 45.11 ± 8.99 to 47.75 ± 11.27 (p = 0.069) and 49.22 ± 10.26 (p = 0.011), respectively. Also in the main group, there was a significant decrease in the manifestations of depression on two scales and an improvement in the functional connectivity of the networks of the passive mode of brain function, executive control and determination of significance according to functional MRI of the brain.