Sleep Duration and Psychological Distress as Key Drivers of EDS, Study Shows

A cross-sectional analysis published in the Journal of Sleep Research found that excessive daytime sleepiness (EDS) is a multifactorial condition strongly associated with sleep duration, quality, and psychological distress. The analysis included anthropometric, lifestyle, socioeconomic, somatic disease, and psychological distress factors, underscoring the need for integrated strategies targeting both sleep and mental health to reduce daytime sleepiness at a population level.¹

Led by Jenny Theorell-Haglöw, PhD, associate professor in respiratory sleep medicine the Department of Medical Sciences at Uppsala University in Sweden, the study utilized clinical and questionnaire data from the Swedish CArdioPulmonary bioImage Study (SCAPIS) cohort. The analysis included 27,976 participants (14,436 women) aged 50–64 years enrolled between 2013 and 2018, using logistic regression to evaluate excessive daytime sleepiness, defined as an Epworth Sleepiness Scale score of 11 or greater, as the primary endpoint.

All told, results showed that shorter sleep duration was associated with progressively higher odds of EDS compared with 8 hours per night, even after adjustment for potential confounders. Both short sleep (no more than 5 hours per night; OR 1.9; 95% CI, 1.4–2.5; P < 0.001) and long sleep (no less than 10 hours per night; OR 3.02; 95% CI, 2.15-4.26; P < 0.001) were associated with the highest odds of EDS. In addition, poor sleep quality, insomnia symptoms, nocturnal gastroesophageal reflux, and snoring were all significantly associated with increased daytime sleepiness.

Psychological distress also demonstrated a strong association with EDS. Factors most prominently linked to increased odds included sadness or depression (OR, 1.2; 95% CI, 1.1–1.3), stress ranging from intermittent to chronic (up to OR, 1.7; 95% CI, 1.3–2.2), and low self-rated “control in life” (lowest quartile: OR, 1.7; 95% CI, 1.6–2.0).

“Our study demonstrated that excessive daytime sleepiness was highly prevalent in the middle‐aged population,” noted study authors.¹ “We confirmed our hypothesis that sleep duration, especially short sleep duration, was independently associated with excessive daytime sleepiness. However, on the population level, modifiable risk factors for EDS such as self‐rated high stress level and lack of life control were almost equally important to sleep duration. Preventive measures of EDS may need to focus equally on sleep health and on psychological health.”¹

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Study authors acknowledged several limitations of the analysis, including the fact that the cohort comprised only middle‐aged adults, limiting generalizability to other age groups. In addition, information on shift work, hypersomnia diagnosis, non-cardiovascular medications, and recent infections was not available. Because the data were cross‐sectional, causality could not be established, nor could changes over time, incidence rates, or longitudinal trends be assessed. Finally, all measures were self-reported.

Previous studies have pointed toward EDS carrying broader health implications than previously recognized by researchers. In a journal article published in Heart, EDS was analyzed in the role it plays in causing cardiovascular risk compared to non-sleepy patients. The investigation aimed to highlight evidence that EDS increases cardiovascular risk in the presence of sleep disorders such as obstructive sleep apnoea, narcolepsy and idiopathic hypersomnia and to propose the notion that EDS may also increase cardiovascular risk in the absence of known sleep disorders, as supported by some epidemiological and observational data.²

Investigators highlighted preliminary evidence in the previous study suggesting systemic inflammation, which could be attributable to dysfunction of the gut microbiome and adipose tissue, as well as deleterious epigenetic changes, that may promote EDS while increasing cardiovascular risk. Researchers also note that these pathways may be reciprocal or circumstantial, and gaps within the literature are noted followed by directions for future research.²

REFERENCES
1. Theorell-Haglöw J, Ulander M, Brandberg J, et al. What are the important risk factors for excessive daytime sleepiness in a population-based cohort?. J Sleep Res. 2025;34(4):e14449. doi:10.1111/jsr.14449
2. Bock J, Covassin N, Somers V. Excessive daytime sleepiness: an emerging marker of cardiovascular risk. Heart. 2022;108(22):1761-1766. doi:10.1136/heartjnl-2021-319596