Daytime Napping Tied to Dementia Risk in Older Adults

A study of Medicare beneficiaries suggests frequent and unintentional naps may signal early cognitive decline independent of nighttime sleep quality. RT’s Three Key Takeaways: Frequent Sleep Association : Older adults who nap most days or every day face a 48% higher risk of developing dementia compared to those who rarely or never nap, according to a study by researchers at the Johns Hopkins Bloomberg School of Public Health.

Unintentional and Brief Naps : Falling asleep unintentionally was tied to a 39% increased risk of dementia, and napping for 30 minutes or less was linked to a 40% higher risk after adjusting for confounding variables. Potential Clinical Marker : Investigators noted daytime napping patterns may reflect early neurodegenerative changes in wakefulness-regulating brain centers, offering an accessible indicator to identify patients at elevated risk.

How often, how intentionally, and how long older adults nap during the day may be linked to their risk of developing dementia, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health. Published in The Journal of Gerontology: Medical Sciences , the study evaluated 995 US Medicare beneficiaries aged 65 and older who were dementia-free at baseline in 2013, according to the organization.

Using data from the National Health and Aging Trends Study (NHATS), the research team followed participants for up to 10 years. The findings showed that individuals who napped frequently—defined as most days or daily—had a 48% higher risk of developing dementia than those who rarely or never napped, according to the study.

This association remained significant even after adjusting for demographic variables, existing health conditions, and nighttime sleep parameters, including total sleep duration, daytime sleepiness, and measures of obstructive sleep apnea (OSA) risk. Nap Duration and Intentionality The analysis also explored the intentionality and duration of daytime sleep episodes.

Unintentional napping, defined as falling asleep without planning to, was associated with a 39% increased risk of dementia, according to the researchers. Additionally, napping for 30 minutes or less was linked to a 40% higher risk of dementia, an effect that persisted after controlling for potential confounders.

In contrast, the association between dementia risk and naps lasting longer than 30 minutes weakened once nighttime sleep factors were included in the models, the authors reported. “More frequent napping could be a marker of changes in the brain, rather than a cause of brain changes that lead to dementia,” said Adam Spira, PhD, MA, senior author of the paper and professor in the Bloomberg School’s Department of Mental Health.

A Bidirectional Relationship The investigators emphasized a probable bidirectional relationship between daytime sleep habits and cognitive decline. While altered napping behavior may represent a risk factor, early degeneration in the brain regions responsible for regulating wakefulness may also drive the urge to nap more often during the day, according to the study.

To evaluate whether napping merely reflected preclinical dementia, the researchers conducted a sensitivity analysis excluding participants diagnosed with dementia within the first five years of follow-up. According to the news release, the associations for frequent and unintentional napping remained consistent, indicating that changes in daytime sleep habits may meaningfully precede clinical cognitive impairment.

“Monitoring napping behaviors could serve as an early and accessible marker to help identify older adults at higher risk for dementia and guide targeted interventions for dementia prevention,” said Kening Jiang, PhD, first author of the paper and postdoctoral fellow in the Bloomberg School’s Department of Mental Health, in a news release.

Clinical Considerations for Healthcare Providers Prior research evaluating napping and cognitive performance has produced mixed results across literature, with some analyses indicating increased risk and others suggesting cognitive preservation from short naps, according to the researchers.

The authors noted that variations in study methodologies, including reliance on self-reporting versus wearable actigraphy, along with regional and cultural attitudes toward napping, contribute to these discrepancies. The authors cautioned that their findings are observational and cannot establish direct causality between daytime napping and incident dementia.

Furthermore, napping data were self-reported, which introduces potential recall bias, and dementia cases were identified through a validated algorithmic classification rather than in-person clinical examinations, according to the report. The study authors concluded that future research utilizing objective, continuous measures of both nighttime sleep quality and daytime napping is needed to confirm the pathophysiological link and determine whether clinical interventions targeting sleep architecture can delay or mitigate dementia onset in aging populations.