Mental illness cited in asthma link to suicide

NEW YORK (Reuters Health) - New research indicates that asthma is significantly linked to suicidal thoughts and suicide attempts, but after accounting for mental health conditions and smoking, the association is markedly weakened.

A number of studies have shown increased rates of suicidal ideation and suicide attempts among individuals with asthma and other respiratory diseases. Why this is so, however, has been unclear, according to the report in the Annals of Allergy, Asthma, and Immunology.

Common risk factors that may soften the association have often not been taken into account in prior studies, note Dr. Diana E. Clarke, from The Johns Hopkins School of Public Health in Baltimore, and her associates.

Their current investigation involved an analysis of data from 5692 individuals drawn from a nationally representative sample of English-speaking adults.

Overall, 8.7 percent of subjects had suicidal ideation without actual attempts at some point in their lives and 4.2 percent of subjects had ideation with attempted suicide. The prevalence of asthma was 12.0 percent.

Many of the factors that correlated with suicidal ideation were the same as those seen with asthma, including younger age, being female, current smoking, nicotine dependence, major depression, and alcohol abuse.

Asthma was significantly associated with suicidal ideation with suicide attempts but not without attempts, the researchers found. The strength of the association, however, fell with adjustment for smoking, nicotine dependence, age, sex, and race and then again after accounting for depression, panic disorder and alcohol abuse.

Nonetheless, on final analysis, asthma remained significantly associated with suicidal ideation with suicide attempts, the report shows.

"More research is needed to further elucidate the mechanism of the remaining association between asthma and suicide attempts," the authors conclude. "Modification of smoking behaviors and effective treatment of depression, anxiety, alcohol abuse, and possibly asthma are important suicide prevention strategies."

SOURCE: Annals of Allergy, Asthma, and Immunology, May 2008.