Abstract
BACKGROUND: Sleep disturbances are common in aging, post-traumatic stress disorder (PTSD), and long COVID, often linked to neuroinflammation, autonomic dysregulation, and neurodegeneration. Hyperbaric oxygen therapy (HBOT) promotes neuroplasticity through the hyperoxic-hypoxic paradox, improving cerebral perfusion, mitochondrial function, and reducing inflammation. While HBOT benefits sleep in certain conditions, its general effects across clinical populations remain unclear. METHODS: This retrospective longitudinal study evaluated Pittsburgh Sleep Quality Index (PSQI) changes in patients undergoing 60 HBOT sessions (2.0 ATA, 100% oxygen, 90 min, 5 days/week) at the Sagol Center. Participants included individuals treated for healthy aging (n = 180), long COVID (n = 92), or PTSD (n = 123). Pre- and post-treatment PSQI total and component scores were compared using paired t-tests and Wilcoxon signed-rank test was used for PSQI components. Regression analysis identified predictors of improvement. RESULTS: Among 395 patients (mean age at baseline 57.9 ± 14.6 years, 31% female), baseline PSQI scores were highest in PTSD. Post-HBOT, total PSQI scores improved significantly in all groups (p < 0.001; Cohen's d = 0.37-0.91). Significant gains were observed in subjective sleep quality, sleep latency, and disturbances in all groups; daytime dysfunction improved in aging and long COVID but not PTSD. Medication use was unchanged. Baseline PSQI was a strong predictor of improvement (B = 0.494, p < 0.001, r = 0.46). Those with disturbed sleep (PSQI>5) showed broad, statistically significant gains, while normal sleepers exhibited minimal changes. CONCLUSION: HBOT was associated with improvement in sleep quality across diverse conditions, with greatest benefit in patients with poorer baseline sleep. Findings support HBOT's potential as a sleep-modulating therapy, warranting controlled trials to characterize the patients that can benefit the most and elucidate mechanisms.