Staying up late could leave you unhappy the next day with cycling negative thoughts and worries. Research psychologists from Binghamton University measured just how detrimental a late bedtime can be on the mind and published their findings in the journal Cognitive Therapy and Research.

“If further findings support the relationship between sleep timing and repetitive negative thinking, this could one day lead to a new avenue for treatment of individuals with internalizing disorders,” the study’s coauthor Dr. Meredith Coles said in a statement. “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.”

Researchers surveyed 100 students on their everyday sleep habits and then put them through computerized tasks in order to gauge how often and to what degree their repetitive negative thinking (RNT) occurs. The subjects were measured on how much they worried, ruminated, or obsessed over something. What is going on inside the human brain when it's sleep deprived? Those who described themselves as night owls with a later bedtime had significantly more negative thoughts than morning people.

Morning people also slept longer, which led researchers to think it may be more of a correlation than causality. The link could mean that those who worried more during the day may have later bedtimes because they can’t sleep that well. Worriers could be distinguished by insomnia and irregular sleeping patterns, instead of less sleep causing the worrying and negative thoughts. Either way, repetitive intrusive thinking can lead to depression, anxiety, obsessive compulsive disorder, and post-traumatic stress disorder, especially if it’s chronic sleep deprivation.

"Making sure that sleep is obtained during the right time of day may be an inexpensive and easily disseminable intervention for individuals who are bothered by intrusive thoughts," the study’s coauthor Dr. Jacob Nota said in a statement.

Scientists are just starting to grasp the extent to which our health depends on the length and quality of rest we give our bodies. Sleep typically takes up about a third of every day, which means an average person who lives to be 90 years old will spend over 30 years of it asleep. Chronic sleep deprivation results in daytime sleepiness, slower reflexes, poor concentration, and increased risk of car accidents. Meanwhile, long-term problems, which pose more severe health consequences, include diabetes, high blood pressure, heart disease, stroke, and weight gain.

Source: Nota JA and Coles ME. Duration and Timing of Sleep are Associated with Repetitive Negative Thinking. Cognitive Therapy and Research. 2014.