Asthma and suicidal ideation with and without suicide attempts among adults in the United States: What is the role of cigarette smoking and mental disorders?

Background: Evidence of a respiratory diseases and suicidal ideation and suicide attempts link exists. To improve our understanding of the mechanism underlying these links, there is a need for examination of the relationship between specific respiratory disease, such as asthma, and suicidal ideation and behavior. In addition, studies need to examine many common risk factors that may play a role in the association between asthma and suicidal ideation and suicide behavior. Objective: To examine the association between asthma and suicidal ideation with and without attempts among adults in the United States, specifically investigating the role of cigarette smoking, nicotine dependence, depression, anxiety, and alcohol abuse. Methods: Data on 5,692 individuals 18 years and older were drawn from the US National Comorbidity Survey Replication. Descriptive and multivariate logistic regression analyses were conducted to examine the study objectives. Results: The estimates of lifetime prevalence for suicidal ideation without and with attempts and asthma were 8.7%, 4.2%, and 12.0%, respectively. Being a woman, a current smoker, depressed, anxious, an alcohol abuser, or nicotine dependent increased the likelihood of suicidal ideation with attempts and asthma. Asthma was significantly (P < .001) associated with suicidal ideation with but not without attempts. Adjustment for smoking, nicotine dependence, age, sex, and race/ethnicity decreased the association between asthma and suicidal ideation with attempts by 16%. Similarly, adjustment for depression, panic disorder, and alcohol abuse led to a 12.4% decrease in this relationship. Despite these adjustments, independently or combined, a statistically significant (P = .02) association remained between asthma and suicidal ideation with attempts. Conclusions: Cigarette smoking and concurrent mental health conditions may independently account for significant proportions of the association between asthma and suicidal ideation with attempts. More research is needed to further elucidate the mechanism of the remaining association between asthma and suicide attempts. Modification of smoking behaviors and effective treatment of depression, anxiety, alcohol abuse, and possibly asthma are important suicide prevention strategies.