Benjamin Franklin once said, "Early to bed and early to rise makes a man wealthy, healthy and wise."

According to new research, Franklin was probably right: a new study shows that going to bed earlier means more happiness and less negative and worrisome thoughts.

The study, done by Jacob Nota and Meredith Coles at Binghamton University, found that people who go to bed late and get less sleep are often more overwhelmed by recurrent negative thoughts than those who go to bed early.

The negative thoughts Nota and Coles looked at were those that repeat in the mind and cause worry and anxiety. These thoughts are often associated with mental illness, including anxiety disorders, depression and post-traumatic stress disorder. Also, people with these thoughts often report problems with sleep.

Other studies have looked at these sort of recurring negative thoughts and their link to the amount of sleep.

But does bedtime also affect how such thoughts arise? Nota and Coles sought to find out by surveying 100 university students, asking them questions about their negative thinking, as well as having them participate in computerized tasks. They asked students about their bedtime habits, including the time they go to bed. They also asked students questions about whether they were morning people or evening people.

The surveys showed that those students with later bedtimes had more negative thoughts throughout the day than those who kept to regular bedtimes. Those who called themselves evening people also reported more negative thinking throughout the day. This is the first time researchers have linked bedtime with such thoughts that often accompany mental illnesses.

The study also suggests that problems with sleep could be due to these negative thoughts, suggesting that a way we might battle certain mental illnesses in the future is to diagnose them early and focus those patients on getting enough sleep.

"If further findings support the relation between sleep timing and repetitive negative thinking, this could one day lead to a new avenue for treatment of individuals with internalizing disorders," says Coles. "Studying the relation between reductions in sleep duration and psychopathology has already demonstrated that focusing on sleep in the clinic also leads to reductions in symptoms of psychopathology."

We already know that sleep has physical benefits, too. Not only does sleep help retain memory and boost brain functioning, but consistent lack of sleep can lead to faster brain aging and cognitive decline.

[Photo Credit: Tony Alter/Flickr]