Long Nights, Foggy Minds? Oversleeping May Be Linked to Poorer Cognition, Study Shows

New Delhi: Getting too much sleep may be detrimental to brain health, particularly for individuals with depression, according to a new study published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association. The research, led by the University of Texas Health Science Center at San Antonio, concluded that sleeping nine or more hours a night is linked to poorer cognitive performance, with the strongest negative effects observed in people experiencing depressive symptoms, regardless of whether they were on antidepressants.

The study analyzed data from 1,853 participants in the Framingham Heart Study, a long-term, community-based research initiative overseen by the National Heart, Lung, and Blood Institute. All individuals included were dementia- and stroke-free, aged between 27 and 85, with a mean age of 49.8 years. The research team investigated the interaction between sleep duration, cognitive function, and depression, a known modifiable risk factor for cognitive decline.

The study found that long sleep duration, not short sleep, was associated with poorer performance in global cognition and specific areas such as memory, visuospatial skills, and executive functions. Participants were grouped by depressive symptoms and antidepressant use. The worst cognitive outcomes were observed among long sleepers with depressive symptoms, while no significant associations were found in those using antidepressants without current symptoms.

The researchers concluded that excessive sleep may signal or contribute to cognitive vulnerability, particularly in those with mental health challenges. They called for future large-scale, longitudinal studies to better understand the timing and mechanisms linking sleep disturbances to cognitive decline.

"Also, long-sleepers were more likely to report symptoms of depression," said Vanessa Young, MS, clinical research project manager at the Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases and first author of the study. "Sleep may be a modifiable risk for cognitive decline in people with depression."

Reference: https://news.uthscsa.edu/too-much-sleep-can-hurt-cognitive-performance-especially-for-those-with-depression-ut-health-san-antonio-study-finds/