NEW YORK (Reuters Health) – The presence and severity of mental illness are associated with an increased risk of asthma, according to study findings in the December issue of Chest. Further research, however, is needed to determine the nature of the relationship and the underlying mechanisms.

“The relationship of asthma with psychological factors has been known for centuries, and recently there has been a resurgence of interest in this topic,” Dr. Thomas H. Chun, from Brown University, Providence, Rhode Island, and colleagues point out.

The researchers reexamined the relationship in a representative sample of the US population, using data from 355,710 subjects who participated in the 2006 Behavioral Risk Factor Surveillance System survey. To the authors’ knowledge, this is the largest investigation of the asthma/mental health nexus.

Self-reported poor mental health was directly related to the odds of current asthma, the authors found. Moreover, as the number of self-reported poor mental health days increased, so did the risk of current asthma.

Specifically, the prevalence of asthma was 6.2% among respondents with no mental health issues, 8.7% among those with 1-7days of poor mental health, climbing to 10.0%, 12.8%, and 21.6% for those with 8-14 days, 15-21 days and 22 days or more of poor mental health, respectively.

By contrast, the association between poor mental health and past asthma was less clear.

The findings also confirmed that age, sex, race, smoking, marital status, overall health, exercise, obesity, and socioeconomic status were key correlates of asthma risk.

Agreeing with the authors that more research is needed, editorialist Dr. David M. Mannino, from the University of Kentucky, Lexington, comments that “in the end, this analysis does not really differentiate whether the observed nexus is merely a linkage between two common problems, or indicative of a pathway where one problem is central to the development of the other.”

Reference:
Chest 2008;134:1116-1117,1176-1182.