People who go to bed late appear to have less control over their obsessive thoughts, according to results of a small study.

"That we find that there are specific negative consequences of sleeping at the wrong times, that's something to educate the public about," said Meredith Coles, Professor of Psychology at Binghamton University, State University of New York.The researchers monitored 20 individuals diagnosed with Obsessive-Compulsive Disorder (OCD) -- a common chronic disorder that leads to repetitive behaviour -- and 10 individuals with OCD-like symptoms during one week of sleep.Participants completed sleep diaries and daily ratings of perceived degree of control over obsessive thoughts and ritualised behaviours. 

The researchers found that previous night's bedtime significantly predicted participants' perceived ability to control their obsessive thoughts and compulsive behaviour on the subsequent day."We're really interested in how this kind of unusual timing of sleep might affect cognitive functioning," said Jessica Schubert from University of Michigan Medical School. "One possibility is impulse control. It might be that something about shifting the timing of your sleep might reduce your ability to control your thoughts and your behaviours," Schubert said."So it might make it more likely that you're going to have a hard time dismissing intrusive thoughts characteristic of obsessions, and it might make it more difficult for you to refrain from compulsive behaviours that are designed to reduce the anxiety caused by obsessive thoughts," Schubert added.