Taking longer to get to deep sleep or REM sleep can disrupt memory consolidation and emotional processing, affecting overall rest and cognitive health. And now a recent study makes a shocking link between delayed REM sleep and Alzheimer's disease.

A delay in getting to the rapid eye movement (REM) stage of sleep may be linked to Alzheimer's disease and related dementias, a new study indicates.

However, some research suggests that poor sleep could raise your risk of Alzheimer’s. A study published in November found that 35 percent of people who were considered poor sleepers (and felt excessively tired during the day as a result) went on to develop motoric cognitive risk syndrome (MCR), which is considered a precursor to dementia.