The study appeared in the journal Current Biology.
People with excessive drowsiness during the day were almost three times as likely to have a brain marker for Alzheimer's.
Researchers at UCLA studied the largest surveys available examining rates of progression of Alzheimer’s.
Losing just one night of sleep led to an immediate increase in beta-amyloid, researchers say.
Researchers have developed a blood test that can diagnose Alzheimer’s with 90 percent accuracy.