"Although depression is treatable, its impact on longitudinal asthma outcomes is not clear." Dr. Mark D. Eisner, of the University of California, San Francisco, and colleagues write in the medical journal Annals of Allergy, Asthma, and Immunology.

The researchers examined the impact of depressive symptoms on outcomes and frequency of emergency health care use in 743 adult asthmatics. The subjects were recruited after being hospitalized for asthma and were followed for longer than 2 years.

The researchers documented depression in 18 percent of the participants.

After accounting for age, sex, race/ethnicity, education, and smoking, depressive symptoms were linked to greater severity-of-asthma scores.

Depression was also associated with poorer asthma-specific quality of life, poorer physical health status, more frequent emergency department visits and more additional hospitalizations.