Basta M, Simos P, Vgontzas A, et al. - Using a large population-based cohort in the island of Crete, Greece (3,140 older adults aged > 60 years), researchers explored the connection between objective sleep and cognitive performance in mild cognitive impairment (MCI) individuals. For this investigation, they selected a subsample of 271 candidates with a diagnosis of probable Alzheimer disease (AD; N = 50) or (MCI; N = 121) and 100 persons who were not cognitively impaired (NI). All candidates had extensive neuropsychiatric/neuropsychological evaluation and a 3-day 24-hour actigraphy. According to results, compared with the MCI and NI groups, AD patients had significantly longer 24-hour total sleep time (TST). Findings suggested an association of long 24-hr TST with decreased performance on tasks that placed significant demands on attention and processing speed in the MCI group and the AD group. A link was found between long sleep duration in patients with multidomain subtypes of MCI and critical non-memory cognitive domains. It seems that those who sleep longer will have more severe cognitive impairment within the MCI group.