Adults over the age of 45 at high risk for obstructive sleep apnea (OSA) are significantly more likely to experience poor mental health and to develop new psychiatric conditions over time, according to a large longitudinal study published in JAMA Network Open. The findings reinforce growing evidence that OSA should be understood not only as a sleep or respiratory disorder, but also as a meaningful risk factor for mental illness in later life.
Study Results
The study, led by researchers from the Ottawa Hospital Research Institute, analysed data from the Canadian Longitudinal Study on Aging, a national, community-based cohort. The sample included more than 30,000 adults aged between 45 and 85 (median age 62) and nearly 28,000 at follow-up (median age 65), with an average follow-up period of just under three years.
Risk for OSA was assessed using the validated STOP questionnaire, which screens for snoring, daytime sleepiness, observed apneas, and hypertension. Mental health outcomes were measured using standardised scales for depression and psychological distress, alongside self-reported diagnoses and antidepressant use.
After adjusting for key confounding factors, adults at high risk for OSA were around 40% more likely to have depression, anxiety, or significant psychological distress at both baseline and follow-up. Among participants who had no mental health problems at baseline, high OSA risk was associated with a 20% higher likelihood of developing a new mental health condition by follow-up. Across repeated analyses, high OSA risk was linked to a 44% increase in the odds of poor mental health overall.
Links to Mood Disorders
The researchers point to plausible biological mechanisms connecting OSA and mental illness, including intermittent low oxygen levels, sleep fragmentation, and systemic inflammation. The strongest associations were seen with mood disorders and clinical depression, though links with anxiety and general distress were also consistent.
The findings highlight the need for routine mental health screening in older adults at risk of OSA. Integrating psychological assessment into sleep evaluations could support earlier identification and intervention, reframing OSA treatment not just as a way to improve sleep, but as a preventive strategy for long-term brain, mood, and cardiovascular health.
