Older women who got more exercise and less television time were the least likely to be diagnosed with depression, according to a U.S. study of thousands of women-with physical activity having the biggest impact. According to findings published in the American Journal of Epidemiology on Monday, researchers found that women who reported exercising the most in recent years were about 20 percent less likely to get depression than those who rarely exercised. On the other hand, the more hours they spent watching television each week, the more their risk of depression increased. “Higher levels of physical activity were associated with lower depression risk,” wrote study author Michel Lucas, from the Harvard School of Public Health in Boston. More time spent being active might increase self-esteem and women’s sense of control, as well as the endorphins in their blood, although the study could not prove directly that watching too much television and avoiding exercise cause depression, Lucas said. Women who watched three hours or more of television a day were 13 percent more likely to be diagnosed with depression than those who hardly ever watched television, but Lucas said at least part of that link might be due to women replacing time they could be exercising with television watching. The report included close to 50,000 women who filled out surveys every two years as part of the U.S. Nurses’s Health Study, and covered the years 1992 and 2000. Participants recorded the amount of time they spent watching television each week in 1992, and also answered questions about how often they walked, biked, ran, and swam between 1992 and 2000.