0842 The Age Paradox: PAP Therapy and Depression in OSA

Abstract Introduction Depression affects nearly 40% of older adults with obstructive sleep apnea (OSA), yet treatment outcomes remain poorly understood in this population. While positive airway pressure (PAP) therapy improves depression in middle-aged patients, no systematic review has examined age-specific effects. We investigated whether PAP therapy reduces severe depression outcomes and improves depression symptoms in adults aged ≥65 years compared to younger populations. We addressed a critical gap in geriatric sleep medicine. Methods We searched four databases (MEDLINE, Embase, PsycINFO, Cochrane Library) through August 2024 for studies examining PAP therapy's effect on depression in OSA patients. Primary outcomes were severe depression events: self-harm, emergency department visits, and psychiatric hospitalizations. Secondary outcomes included validated depression scales (HADS-D, PHQ-9, BDI, CES-D). Studies were stratified by age: elderly (≥65 years) versus mixed-age (< 65 years). Two independent reviewers extracted data and assessed bias using Cochrane tools. Random-effects meta-analysis pooled elderly-specific trials. Evidence quality followed GRADE methodology. Results Nine studies (40,240 participants) met inclusion criteria. In mixed-age adults (n=37,459, mean age 50.9 years), PAP adherence dramatically reduced self-harm events by 20% (p< 0.001), emergency visits by 27% (p< 0.001), and psychiatric hospitalizations (p=0.019). Strikingly, four high-quality RCTs in elderly patients (n=553, age ≥65 years) showed zero improvement in depression scales, despite robust improvements in sleepiness (Epworth -2.1 points, p< 0.0001) and quality of life (p< 0.004). This paradox persisted in the largest trial (n=278, 12-month follow-up). Meta-analysis confirmed null effect on depression symptoms (pooled effect -0.12, 95% CI: -0.48 to 0.24, p=0.52, I²=0%). Conclusion Age fundamentally alters PAP therapy's effect on depression in OSA. While PAP prevents severe depression crises in younger adults, it fails to improve depression symptoms in elderly patients, despite clear benefits for sleepiness and function. Clinicians should adjust expectations when treating older patients and consider adjunctive depression management. This finding reveals an urgent need to understand why aging confers treatment resistance and develop age-appropriate interventions. Support (if any)