Connections Between Insomnia and Cognitive Aging

Abstract

Insomnia is a common sleep disorder among older adults, and a risk factor for poor physical and mental health. However, the relationship between insomnia and cognitive health is not well understood. Here, we review observational studies that have investigated whether insomnia is associated with deficits in objective cognitive performance and an increased risk of dementia, magnetic resonance imaging studies that have assessed grey matter volumes and white matter microstructure, and interventional studies that have explored whether the treatment of insomnia can improve cognitive outcomes. There are inconsistent findings regarding impaired performance in objective cognitive tests and reduced grey matter volumes, and limited, emerging, evidence that suggests that insomnia is associated with an increased risk of dementia and reduced white matter integrity. Although the interventional literature is still in its infancy, there is some indication that treatment may have an impact on vigilance. Well-powered studies examining sources of heterogeneity are warranted.

The interrelation of sleep and mental and physical health is anchored in grey-matter neuroanatomy and under genetic control

“…In addition, other neuroimaging meta-analyses have implicated structural and functional abnormalities in the hippocampus, amygdala, and insula in patients with sleep apnea 30 and have indicated convergent functional brain alterations in the inferior parietal cortex and superior parietal lobule, following acute sleep deprivation 31 . Moreover, white matter integrity underlying prefrontal areas has been associated with sleep duration and sleep quality [32][33][34] . Lastly, lower prefrontal gray matter volume has been associated with greater sleep fragmentation in older individuals 35 .…”

The effect of insomnia on development of Alzheimer’s disease

“…Based on these similarities between the pathophysiology of insomnia and mechanisms that cause AD including accumulation of Aβ, inflammation, and other components which are discussed in this review, insomnia disorder can be linked to AD risk [420][421][422] and this could be a novel target for treatments or prevention AD development and/or resolve the cognitive decline in patients with AD in the future [423].…”

Sleep Well and Recover Faster with Less Pain—A Narrative Review on Sleep in the Perioperative Period

“…Prolonged sleep disturbance predisposes a person to mental disorders, such as depression, anxiety, psychosis, and alcohol abuse [ 26 ]. A wide variety of physical diseases have been recognized to be associated with insomnia, e.g., cardiovascular diseases [ 27 ], dementia and cognitive decline [ 28 , 29 ], and obesity [ 30 ]. A large cohort study found a three-fold increased mortality risk in individuals with short sleep duration and persistent symptoms of insomnia [ 31 ].…”