Asthma and anxiety disorders.

In this chapter we have reviewed recent findings on the co-occurrence of asthma and anxiety disorders in youth and adults in clinical and community-based samples. We have not included a review of research on linkages between respiratory functioning and anxiety symptoms, or the linkages between asthma severity and anxiety symptoms, though several recent reviews of these areas are available [see 5, 12]. If possible, future research is needed to disentangle the relationship between asthma and anxiety disorders compared with that with other medical conditions. This may involve using samples that are unselected for either disorder of interest, including population samples where a range of severity is present. Studies that document a relationship between asthma and an increased use of emergency room services for asthma do not indicate that there is a link between asthma and anxiety disorders, but may simply reflect a relationship between mental disorders, which is well-documented, or an association being driven by a common third factor, such as low socioeconomic status, which is linked to both. There are also numerous studies that have investigated the relationship between anxiety symptoms and anxiety disorders and severity, use of treatment, and other clinical correlates of asthma and anxiety, especially panic [see 5 for a review], but a review of this literature is beyond the scope of this chapter. Results of studies to date suggest a link between asthma and anxiety disorders among both youth and adults, and in clinical and community-based samples. Still, many questions about this association remain unanswered. Future work is needed to determine the strength and specificity of the link between asthma and anxiety disorders. The temporal relationship between the onset of asthma and anxiety disorders, and relatedly, the mechanism of this association is also poorly understood. Furthermore, there is mounting evidence of a potential familial relationship between asthma and anxiety disorders, which warrants further investigation, and if replicated it will be important to uncover the mechanism of this association. Another unexplored area is common environmental factors, as emerging evidence suggests that there may be shared risk factors for both asthma and anxiety disorders in youth (e.g., urban residence, parental smoking), and future investigations into this link seem promising. In addition, studies that investigate the linkages between use of specific medications for asthma and the onset of anxiety symptoms and anxiety disorders are needed, both looking at the short- and long-term effects. As there is increasing data that use of specific medications are associated with brain changes, mood and psychotic disorders [41], and there is also emerging evidence of a link between asthma and respiratory disease and suicidal ideation and suicide attempts [42], further investigation into this area is important. Work is currently underway aimed at improving our understanding of the etiology and modifiable risk factors for onset and persistence of the co-occurrence of asthma and anxiety disorders, and the nature of the relationship between the two has the potential to lead to significant improvements in the understanding of etiology and effectiveness of treatment for both, as well as primary and secondary prevention efforts, among youth and adults in the community. The public health significance of both asthma and anxiety disorders, especially with a substantial increase in asthma, and possibly anxiety disorders [13], over the past two decades, highlights the potential import of work aimed at understanding these linkages.