Poor Deep Sleep May Be Fueling Anxiety in Older Adults

Overview

Many people find that as they get older, their sleep becomes lighter and more scattered. It is also a stage of life when anxiety symptoms often become more common. Scientists have known for a long time that poor sleep and anxiety are linked. But new research suggests that deep sleep may play a much bigger role than previously understood.

A new study suggests that disrupted deep sleep may help explain why anxiety tends to increase with age. The research points to a loss of "slow-wave sleep," a restorative form of non-REM sleep that seems vital for the brain's overnight emotional reset.^[1]

Here is what the researchers found—and why deep sleep may matter for emotional health as we age.

A Closer Look at Deep Sleep

Before we get into the study, it is worthwhile to review the meaning of deep sleep. Deep sleep, also known as slow-wave sleep, occurs during non-rapid eye movement (NREM) sleep. During this stage, the brain produces large, synchronized electrical oscillations known as slow waves.^[2]

These slow waves are thought to help the brain regulate emotions, quiet stress responses, and restore communication between areas involved in emotion and thinking.

Experts say slow-wave sleep is like an "overnight recalibration" for the brain when it is stressed. Studies on younger people have already shown that higher slow-wave activity is associated with lower anxiety the next day.^[3]

The new study examined whether the same process could explain why worry often worsens with age.

Why Anxiety in Older Adults Matters

Anxiety in older adults is often overlooked, with symptoms sometimes dismissed as a normal part of getting older. But anxiety in later life can have a major impact on both emotional and physical well-being. It can make it harder to sleep, remember things, be independent, and enjoy life in general. This can make daily tasks feel harder and more tiring.

Research has also linked anxiety in older adults with later cognitive decline.^[4]

Anxiety should not simply be written off as a normal part of aging. Understanding what may contribute to it could help researchers identify better ways to support emotional health in later life.

If inadequate deep sleep or other sleep problems contribute to emotional distress, then improving sleep could be a vital approach to support better aging and safeguard brain health over time.

The Slow Wave Sleep and Anxiety Study

The researchers examined 61 cognitively healthy older adults from the UC Berkeley Aging Cohort, with an average age of 74.6 years.^[1]

Each participant spent the night in the sleep laboratory, where their brain activity was monitored using polysomnography. Participants reported anxiety levels before bedtime and again the next morning.

Each participant also underwent a high-resolution MRI to assess age-related brain shrinkage in regions involved in emotion regulation, including the amygdala, insula, and cingulate cortex. Twenty-four participants returned about four years later for follow-up testing.

The Study’s Results

The pattern was clear: Participants with fewer slow waves during deep non-REM sleep tended to report more anxiety the next morning, while those with stronger slow-wave sleep tended to show less overnight anxiety, regardless of age.

Interestingly, it wasn't just about getting more sleep. What counted was the depth of the sleep. In this study, REM sleep, another stage involved in emotional processing, was not associated with anxiety as strongly as slow-wave sleep.

Brain scans also showed that participants with greater shrinkage in emotion-related regions, including the amygdala and cingulate cortex, produced fewer slow waves during sleep. In the researchers’ analysis, reduced slow-wave sleep accounted for more of the age-related increase in anxiety than brain shrinkage alone.^[1]

What the Study Found

Among the 24 participants who returned about four years later, slow-wave activity had declined by roughly 20% on average, while self-reported anxiety had increased over the same period.^[1]

Those who preserved stronger slow-wave sleep also tended to show better emotional outcomes, reinforcing the study’s link between deep sleep and anxiety across aging.^[1]

Deep Sleep Regulation & Emotional Health

The researchers propose two possible mechanisms. First, during deep sleep, the autonomic nervous system shifts away from the body’s more alert “fight-or-flight” state toward a calmer “rest-and-recover” state. This shift may help restore physiological balance and reduce next-day stress reactivity.

Second, declining slow-wave activity may be related to changes in the locus coeruleus, a small brainstem region involved in producing noradrenaline, a chemical that helps regulate alertness and arousal. Age-related changes in this region occur during the same general period of life in which slow-wave sleep declines.^[5]

Researchers therefore speculate that changes in the locus coeruleus and reductions in slow-wave sleep may be connected. If future studies confirm that relationship, slow-wave activity could potentially serve as a marker of changes in this brain region.

Implications & Next Steps

The study's findings reveal a vulnerability in the aging brain, but also a cause for optimism.^[1] Results point to the possibility that age-related anxiety may not be caused only by irreversible changes to the brain.

That makes slow-wave sleep an important target for future research into ways of supporting emotional health in older adults.

Unlike age-related brain atrophy, some aspects of sleep can potentially be improved. Researchers now want to determine whether preserving or enhancing slow-wave sleep can meaningfully reduce anxiety as people age.

Future studies may test approaches such as acoustic stimulation and other methods designed to enhance slow-wave sleep to see whether they can reduce anxiety and support healthy brain aging.

References:

Ben Simon, E., Shah, V. D., Murillo, O., Zsofia, Z., & Walker, M. P. (2026). Impaired slow-wave sleep accounts for brain aging-related increases in anxiety. Communications Psychology, 4(1), 34. https://doi.org/10.1038/s44271-026-00401-2
Roth T. (2009). Slow wave sleep: does it matter?. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 5(2 Suppl), S4–S5.https://pmc.ncbi.nlm.nih.gov/articles/PMC2824210/
Arpaci, H., Banik, N., Ersoy, P. K., Harrington, C., Kapucu, A., & Baran, B. (2025). NREM sleep oscillations are associated with anxiety and negative affect in young adults. Journal of Sleep Research, 34(5), e70050. https://doi.org/10.1111/jsr.70050.
Sinoff, G., & Werner, P. (2003). Anxiety disorder and accompanying subjective memory loss in the elderly as a predictor of future cognitive decline. International journal of geriatric psychiatry, 18(10), 951–959. https://doi.org/10.1002/gps.1004.
Liu, K. Y., Marijatta, F., Hämmerer, D., Acosta-Cabronero, J., Düzel, E., & Howard, R. J. (2017). Magnetic resonance imaging of the human locus coeruleus: A systematic review. Neuroscience and biobehavioral reviews, 83, 325–355. https://doi.org/10.1016/j.neubiorev.2017.10.023.