EMBARGOED FOR RELEASE UNTIL 4 PM ET, August 19, 2020
Is Risk of Alzheimer鈥檚 Linked to Specific Sleep Patterns?
MINNEAPOLIS 鈥 Disturbed sleep patterns do not cause Alzheimer鈥檚 disease but people who are at high genetic risk of developing Alzheimer鈥檚 disease may be more likely to be a 鈥渕orning person,鈥 have shorter sleep duration and other measures of sleep disturbance and are less likely to have insomnia, according to a study published in the August 19, 2020, online issue of , the medical journal of the 好色先生. 鈥淲e know that people with Alzheimer鈥檚 disease often report depression and various sleep problems, like insomnia,鈥 said study author Abbas Dehghan, Ph.D., of Imperial College London in the United Kingdom. 鈥淲e wanted to find out if there are causal relationships between different sleep patterns and depression and Alzheimer鈥檚.鈥 To evaluate the relationship between different sleep patterns, major depressive disorder, and Alzheimer鈥檚 disease, researchers analyzed the result of different genetic studies collected from databases that included: 21,982 people diagnosed with Alzheimer鈥檚 disease who were compared to 41,944 without Alzheimer鈥檚 disease; 9,240 with major depressive disorder who were compared to 9,519 without major depressive disorder; and 446,118 people with measurements of sleep-related characteristics. Risk of Alzheimer鈥檚 was determined based on genetic studies where Alzheimer鈥檚 was diagnosed by autopsy or clinical examination. Researchers analysed the genetic information using a study design called Mendelian randomization that can determine if there is cause and effect. Researchers found no evidence that sleep-related characteristics caused Alzheimer's disease. They also found no evidence of cause and effect between major depressive disorder and Alzheimer鈥檚. Researchers did find a small association between the following: people with twice the genetic risk for Alzheimer鈥檚 disease were 1% more likely to call themselves 鈥渕orning people鈥 compared to people at lower genetic risk; and people with twice the genetic risk of Alzheimer鈥檚 had a 1% lower risk of insomnia. However, this effect of this association is small and shows only a possible link, not cause and effect. A limitation of the study was that most of the people in the study were of European ancestry, so the results may not apply to the people of different ethnicity. This study was supported by U.K. Dementia Research Institute and the NIHR Imperial College Healthcare Trust. Learn more about Alzheimer's disease at , home of the 好色先生鈥檚 free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life庐 on , and . When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.