A new study has found that getting a good night's sleep, which is defined as 7-9 hours, can prevent dementia.

The Mayo Clinic defines insomnia as a common sleep disorder that can make it hard to fall asleep or stay asleep. It also can cause you to wake up too early and not be able to get back to sleep.

For the study, researchers ran brain scans and sleep assessments on nearly 3,000 people over five years. They found those with insomnia faced a 40% higher chance of cognitive decline.

People who improved their sleep either by taking medication or making lifestyle changes did not have the same risks.

"We can have the medication helping us, but we still have a part we need to play to make this work by exercising, having a healthy diet and making sure we have proper and adequate sleep." Dr. Paul Wright, chair of the Nuvance Health Neuroscience Institute.

Wright says when people sleep, their brains go into what he describes as "cleanup mode" to clear out metabolic waste including neurotoxins, amyloid and tau proteins, all hallmarks of Alzheimer's.

People in need of a good rest, which is essential for memory and emotional health, should establish a bedtime, limit caffeine, alcohol and screen time plus regularly exercise.

For those who have tried all of those suggestions and still feel that they are not getting sufficient sleep, it's recommended they work with a sleep specialist.