Women, people with lower income and people with less education are the most stressed in the United States, researchers found. Sheldon Cohen and Denise Janicki-Deverts of Carnegie Mellon University used telephone survey data from 1983 that polled 2,387 U.S. adults, and online surveys in 2006 and 2009 that polled 2,000 American adults each. All three surveys used the Perceived Stress Scale, a measure created by Cohen to assess the degree to which situations in life are perceived as stressful. The study, published in the Journal of Applied Social Psychology, found Americans experience less stress as they age and retirees consistently reported low levels of stress -- indicating retirement is not experienced as an adverse event. However, Cohen and Janicki-Deverts found those most negatively affected by the 2008-2009 economic downturn were white, middle-aged men with college educations and full-time jobs. \"We know that stress contributes to poorer health practices, increased risk for disease, accelerated disease progression and increased mortality,\" Cohen said in a statement. \"Differences in stress between demographics might be important markers of populations under increased risk for physical and psychological disorders.\" It\'s clear that stress is still very much present in Americans\' lives, putting them at increased risk for diseases such as cardiovascular, asthma and autoimmune disorders, Cohen added.pe