Researchers studying a link between asthma and obesity have found that childhood depression may be an important piece of the puzzle. A recent issue of the International Journal of Obesity featured a study of 600 men and women with asthma. It was found that those who had asthma symptoms at age 20 were more than 3 times as likely to be obese by age 40 as people who did not have asthma symptoms. A common thread in many of these cases appeared to be childhood or adolescent depression, which may contribute to subsequent excessive weight gain. Previous studies differed over which appeared first—asthma or obesity. It is possible that asthma medications may cause their users to put on weight, or that an inability to exercise may be the cause—although the study participants' activity levels did not reflect this inability. Gregor Hasler, MD, of the University Hospital Zurich in Switzerland, speculated that the link between early depression and a subsequent asthma-obesity combination may be that the early depression signals a stressful family life, and psychological stress is a risk factor for both asthma and obesity. He said that all 3 disorders are marked by widespread inflammation in the body, and perhaps genes that regulate this inflammation also may contribute to depression, asthma, and obesity.

Ms. Farley is a freelance medical writer based in Wakefield, RI.