Get stressed in traffic jams? Be warned. It could harm your mental health years later As most of us know only too well, even at the best of times they're just plain infuriating. But being stuck in one queue or traffic jam too many could spark more than simply a foul mood - it can lead to severe mental disorder, a study claims. Everyday irritations such as waiting in traffic can build up over time and cause mental problems later in life, psychologists found. And learning to keep a cool head in the face of modern life's daily stresses is as essential as a healthy diet and an exercise routine, they said. Susan Charles, a professor of psychology and social behaviour, led the study to find out whether everyday irritations add up to make the straw that breaks the camel's back, or whether they make us stronger. Using data from two national surveys, researchers found negative responses to daily stresses such as arguments with a partner, conflicts at work, standing in long queues or sitting in traffic led to psychological distress or anxiety and mood disorders ten years later. The results, based on data from the Midlife Development in the United States project and the National Study of Daily Experiences, from men and women aged 25 and 74, show mental health problems are not affected by just major life events, but also by seemingly minor emotional experiences. The findings echo the premise of the 1993 Michael Douglas film Falling Down, in which his character "snaps" while waiting in LA traffic. Speaking of the findings, published in the journal Psychological Science, Professor Charles said: "How we manage daily emotions matters to our overall mental health. It's important not to let everyday problems ruin your moments. Professor Charles, of the University of California, Irvine, added: "Unfortunately, people don't see mental health problems as such until they become so severe that they require professional attention." ■ Middle managers are under the most stress in the workplace, a study claims. This is because they face more challenges from above while having to maintain authority over lower-ranking workers. In the study, experts at the universities of Manchester and Liverpool monitored stress hormones in monkeys. Among the findings, which they said could be applied to human hierarchies, was that monkeys in the middle order had the highest levels of stress hormones. They are involved with conflict from those below as well as from above. Katie Edwards, from Liverpool's Institute of Integrative Biology, said: "People in middle management might have higher levels of stress hormones compared to their boss at the top or the workers they manage."