Lung disease is associated with an increased risk of mental health problems, according to findings published in the American Journal of Epidemiology.

Dr. Renee D. Goodwin, of Columbia University, New York, and colleagues examined data from a representative sample of U.S. adults between the ages of 25 and 74 years. The subjects were enrolled in the First National Health and Nutrition Examination Survey, from 1971 to 1975.

Measurements of lung function were performed and patients received a preliminary diagnosis of restrictive lung disease or obstructive lung disease. Evaluations of mental health were also conducted.

The study included 642 subjects with restrictive lung disease, characterized by a decrease in exhaled airflow, such as asthma, emphysema or bronchitis; 68 with obstructive lung disease, a decrease in total volume of air that the lungs can hold, which can result from loss of elasticity of the lung or problems with the expansion of the chest wall during inhalation; and 4,776 with normal lung function.

Compared with individuals with normal lung function, those with obstructive or restrictive lung function were significantly more likely to have mental health problems.

Specifically, obstructive lung function was associated with significantly lower feeling of overall well-being. Restrictive lung function was associated with lower scores on feelings of overall well-being, general health, vitality and self-control, and higher depression scores.

The reason for the association between lung function and mental health problems is unclear, Goodwin’s team notes. They suggest that impaired lung function may lead to a decreased sense of well-being as a result of physical limitations associated with physical disease.

Even patients who do not have functional limitations may experience distress over poor physical health, the researchers add, and this may lead to depression and worry.

SOURCE: American Journal of Epidemiology, February 2007.