Staying up late for many nights without sleep can lead to anxiety and negative thoughts. A study by Birmingham University found this information and published it in a journal. Researchers at the university allowed 100 students to fill out several questionnaires. In addition to this they are allowed to do two things on the computer through which their negative thinking tendency or repetitive negative thinking (RNT) is understood. In addition, information was obtained about their sleep habits and timing. Previous studies have shown that students who say they like to wake up at night and wake up late are more likely to have negative thoughts. People who wake up in the morning and get enough sleep are less likely to have this problem. This information shows a correlation between sleep deprivation and negative thinking. But it could also be that they are losing sleep because of anxiety in the morning. This new study supports the previous study. However, this is the first time that a link has been found between repeated negative thinking and less sleep. These thoughts often lead to complications such as depression , anxiety , OCD, PTSD .