1 Inflammation and Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
2 Department of Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
3 School of Epidemiology and Public Health, University of Ottawa, Ottawa, Ontario, Canada.
4 Ottawa Methods Centre, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
5 Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
6 School of Psychology, University of Ottawa, Ottawa, Ontario, Canada.
7 Sleep Research Unit, Royal Ottawa Institute of Mental Health Research, Ottawa, Ontario, Canada.
8 Bruyere Health Research Institute, Ottawa, Ontario, Canada.
9 Department of Health, Kinesiology, and Applied Physiology, Concordia University, Montréal, Québec, Canada.
10 Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), Centre intégré universitaire de soins et services sociaux (CIUSSS) du Centre-Sud-de-l'île-de-Montréal, Montréal, Québec, Canada.
11 Department of Family Medicine and Primary Care, Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong, SAR of China.
12 Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
13 Department of Psychiatry, University of Ottawa, Ottawa, Ontario, Canada.

Importance: Despite plausible mechanisms linking obstructive sleep apnea (OSA) and mental health conditions, prospective studies from representative samples are needed to estimate temporal associations between OSA and mental health conditions during aging.

Objective: To evaluate whether high risk of OSA is associated with increased odds of concurrent and future mental health conditions among middle-aged and older adults.

Design, setting, and participants: This cohort study is a secondary analysis of the Canadian Longitudinal Study on Aging (CLSA) and used data from respondents of the CLSA Baseline Comprehensive Cohort (2011-2015) and Follow-up 1 (2015-2018) who were aged 45 to 85 years at baseline. Statistical analysis was performed October 2024. The CLSA is a national community-based prospective cohort study collecting data on the biological, medical, cognitive, psychological, social, lifestyle, and economic aspects of aging.

Exposure: Individuals with a score greater or equal to 2 on the STOP (snoring, daytime somnolence, witnessed apnea during sleep, or hypertension) questionnaire were considered at high risk of OSA.

Main outcome and measures: A composite poor mental health outcome was computed as a binary variable, defined by the presence of any of the following: (1) Center for Epidemiologic Studies Short Depression Scale score of 10 or more, (2) Kessler Psychological Distress Scale score of 20 or more, (3) self-reported physician-diagnosed mental health condition, or (4) self-reported antidepressant use. Multivariate conventional and mixed logistic regressions were used to examine associations.

Results: The study included 30 097 individuals at baseline (median age, 62 years [IQR, 54-71 years]; 50.9% women) and 27 765 individuals at follow-up (median age, 65 years [IQR, 57-73 years]; 50.9% women), with a median follow-up of 2.9 years (IQR, 2.8-3.1 years). A total of 7066 of 30 097 individuals (23.5%) at baseline and 7493 of 27 765 individuals (27.0%) at follow-up were at high risk of OSA. The composite mental health outcome was identified in 10 334 of 30 097 individuals (34.3%) at baseline and 8851 of 27 765 individuals (31.9%) at follow-up. In adjusted models, high risk of OSA was associated with an approximately 40% higher odds of the composite outcome concurrently at baseline (odds ratio [OR], 1.39; 95% CI, 1.28-1.50) and at follow-up (OR, 1.40; 95% CI, 1.30-1.50). In a repeated-measures analysis, OSA risk remained associated with a 44% higher odds (OR, 1.44; 95% CI, 1.34-1.53) of the composite outcome.

Conclusions and relevance: In this national longitudinal cohort study, middle-aged and older adults at high risk of OSA had consistently worse mental health outcomes. These findings bridge knowledge gaps on the association between OSA and mental health, highlighting the need for integrated screening and intervention strategies.