WASHINGTON (CBSDC) - A new study shows poor sleep patterns can play a major contributing role in the development of Alzheimer’s and other mental deficiencies.

Health Day News says that too much sleep or not enough sleep can equal to that of two years of aging to the brain, according to one study.

Another study shows that people suffering from sleep apnea are more than twice as likely to develop mild thinking problems, such as dementia, than people who get regular, unimpaired sleep.

A third study conducted shows that excessive daytime sleepiness may give a glimpse into a future that holds deteriorated memory and thinking skills, better known as cognitive decline.

One of the studies followed 15,000 women over the course of 14 years in the U.S. Nurses’ Health Study, confirmed that those who slept either five hours a day or less, or nine hours a day or more, were left with lower average mental functioning than the participants who slept a seven hour day regularly. Lack of sleep or oversleeping equaled to mental aging of two years.

The results are only considered preliminary at this point because they have yet to be peer-reviewed and published in a medical journal.