Excessive Sleep Duration Can Impair Cognitive Function, Especially in Individuals with Depression

Recent research highlights that sleeping nine hours or more each night may negatively impact cognitive performance. Led by scientists at the University of Texas Health Science Center at San Antonio, the study examined sleep habits and mental function in 1,853 individuals from the Framingham Heart Study, aged between 27 and 85 years, with an average age of nearly 50. The findings revealed that longer sleep durations are linked to poorer overall cognitive abilities, including memory, visuospatial skills, and executive functions. This association was significantly stronger among participants experiencing depressive symptoms.

Additionally, researchers observed that those who sleep longer were more likely to report symptoms of depression, suggesting a complex relationship between sleep, mood, and cognitive health. Vanessa Young, the study’s lead author, emphasized that sleep is a modifiable risk factor for cognitive decline, especially in individuals with depression.

Existing evidence underscores the importance of maintaining a healthy sleep pattern, typically between 7 to 8 hours per night, for optimal brain health. Disruptions in sleep duration and quality can contribute to cognitive deficits and increase the risk of developing neurodegenerative conditions like Alzheimer’s disease. The global health community recommends adhering to this sleep duration to support cognitive longevity.

The study further explored whether depression influences the relationship between sleep and cognitive function. Results indicated that long sleep duration was associated with reduced cognitive performance primarily in individuals with depressive symptoms, whether they used antidepressants or not. Conversely, no significant impact was observed in participants without depressive symptoms who used antidepressants.

In conclusion, the research emphasizes that excessive sleep can pose risks to cognitive health, particularly among those experiencing depression. Addressing sleep issues and depressive symptoms could be key strategies in preserving brain function over time.

Source: https://medicalxpress.com/news/2025-05-cognitive-depression.html