Why Getting Enough Sleep Is Critical for Brain Health

• “A systematic review and dose-response meta-analysis of sleep duration and the occurrence of cognitive disorders,” Sleep and Breathing, September 2018. For this meta-analysis, researchers analyzed data from nine studies, which comprised more than 22,000 participants. They concluded that participants who slept 7–8 hours a night had the lowest risk of cognitive disorders. As a population study, it shows a correlation but does not prove cause and effect. Read a summary of the study. (A fee is required to access the full study.)

• “Association Between Sleep Duration and Cognitive Decline,” JAMA Network Open, September 2020. In this study, researchers analyzed more than four years of data from more than 20,000 adults ages 45 and older. They found evidence that getting four hours or less of sleep per night as well as 10 hours or more was associated with faster cognitive decline compared to getting seven hours per night. As a population study, it shows a correlation but does not prove cause and effect. Read the full study.

• “The Sleeping Brain: Harnessing the Power of the Glymphatic System through Lifestyle Choices,” Brain Sciences, November 2020. This scientific paper explores the research on the glymphatic system and how it helps to mitigate the risk of Alzheimer’s disease during sleep. Read the full paper.

• “Extended Wakefulness: Compromised Metabolics in and Degeneration of Locus Ceruleus Neurons,” Journal of Neuroscience, March 2014. Researchers examined the brains of mice after allowing them periods of normal rest, short wakefulness and extended wakefulness. Researchers found that extended periods of lack of sleep are linked to damage to the neurons that are essential for staying alert. Read the full study.

• “Sleep deprivation causes memory deficits by negatively impacting neuronal connectivity in hippocampal area CA1,” eLife, August 2016. In this mouse study, researchers found that five hours of sleep deprivation reduced connections between neurons in the hippocampus but that three hours of makeup sleep helped neuron activity return to normal. Read the full study. 

• “Connections Between Insomnia and Cognitive Aging,” Neuroscience Bulletin, January 2020. This scientific paper explores the research behind insomnia, gray matter volumes, white matter microstructure and cognition. Read a summary of the article. (A fee is required to access the full study.)

• “The role of slow wave sleep in the development of dementia and its potential for preventative interventions,” Psychiatry Research: Neuroimaging, December 2020. This scientific paper explores the research behind what happens in the brain during the deepest sleep stage, known as slow wave sleep (SWS) or non-rapid eye movement (NREM) sleep, and the implications for helping to prevent cognitive decline and Alzheimer’s disease. Read the full article.