People who sleep for shorter periods of time and go to bed very late at night are often overwhelmed with more negative thoughts than those who keep more regular sleeping hours, a new study has found.

People are said to have repetitive negative thinking when they have bothersome pessimistic thoughts that seem to repeat in their minds.

Previous studies have linked sleep problems with such repetitive negative thoughts, especially in cases where someone does not get enough shut eye.

Jacob Nota and Meredith Coles of Binghamton University in the US, set out to determine if there is a link between repetitive negative thoughts and the actual time when someone goes to bed.

They asked 100 young adults at Binghamton University to complete a battery of questionnaires and two computerised tasks.

In the process, it was measured how much the students worry, ruminate or obsess about something – three measures by which repetitive negative thinking is gauged.

The researchers found that people who sleep for shorter periods of time and go to bed later often experience more repetitive negative thoughts than others. This was also true for those students who described themselves as evening types.

The findings also suggest that sleep disruption may be linked to the development of repetitive negative thinking.

The findings appear in Springer’s journal Cognitive Therapy and Research.