According to the “Sleep in the City” study, Detroit, Cleveland, and Nashville were the three worst cities for sleep, while Minneapolis, Anaheim, and San Diego were the three most well rested places.

Conducted by national research expert Bert Sperling, in partnership with prescription-strength sleep aid Ambien, the “Sleep in the City” study ranked the United States’ 50 most populous metropolitan areas using recent data from the Centers for Disease Control and Prevention, data from the Bureau of Labor Statistics, and data from the U.S. Census Bureau.

The 50 cities were ranked based on five criterion: the number of days in the past month that residents reported not getting enough sleep, the average commute time, the divorce rate, the unemployment rate, and the overall happiness index, which was derived from questions about individual’s emotional, mental, and physical health.

“Sleep has a significant effect on a person’s well-being; persistent poor sleep can cause people to feel Ôout of touch’ with what’s going on in their lives,” said Ellen Miller, MD, a clinical assistant professor of medicine at the Albert Einstein College of Medicine. “Not getting enough sleep may lead to increased irritability, risk for depression, or weight gain. Recent evidence also suggests that persistent poor sleep, left untreated, may even cause more serious conditions.”

This survey is a more crucial examination of the nation’s health than most might think. More and more public health officials are recognizing sleep as an important part of a person’s health, as sleep deficiency has been linked to motor vehicle crashes, industrial disaster, and medical and other occupational errors. In fact, a study from the AAA Foundation for Traffic Safety found that people who sleep six to seven hours a night are twice as likely to be involved in a crash as those who sleep eight hours or more. The AAA’s study also found that those who slept less than five hours increased their four to five times. This means that the best rested cities may also be some of the safest cities, too, having a lower risk of accident than other, tired cities.

According to the National Sleep Foundation’s chief executive officer Richard Gelula,”If you’ve been sleeping poorly for some time and recognize that your sleepless nights are affecting your days, it may be time to talk to a doctor.”