Medscape: Short and long sleep duration in older individuals are both associated with impaired cognition, new research suggests.

However, imaging data reveal only short sleep is linked to greater amyloid beta (Aβ) burden. 

In a large, cross-sectional study of patients older than 64 years, Mini-Mental State Examination (MMSE) scores were .08 points lower among those with short sleep duration vs individuals with normal sleep duration, while Digit Symbol Substitution Test (DSST) scores were 1.17 points lower in the long sleep group vs the normal sleep group.

Short sleep duration was defined as 6 hours or less and long sleep duration was defined as 9 hours or more.

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