Study shows that a nightly sleep duration of six to nine hours is associated with higher ratings for quality of life and lower ratings for depression.

American Academy of Sleep Medicine, June 14, 2011

http://www.eurekalert.org/pub_releases/2011-06/aaos-tgl060911.php

DARIEN, IL – Getting six to nine hours of sleep per night is associated with higher ratings for quality of life and lower ratings for depression, suggests a research abstract that will be presented Tuesday, June 14, in Minneapolis, Minn., at SLEEP 2011, the 25th Anniversary Meeting of the Associated Professional Sleep Societies LLC (APSS).

Results show that people with a "normal" sleep duration of six to nine hours per night had higher self-reported scores for quality of life and lower scores for depression severity compared to short and long sleepers. These differences were statistically significant in all comparisons. Among patients who reported having perfect health, there were a higher percentage of normal sleepers, who also had significantly lower scores for depression severity compared to short and long sleepers with perfect health.