Anxiety but not depression symptoms are associated with greater perceived dyspnea in asthma during bronchoconstriction

Objective:

To determine whether anxiety and depression are associated with greater respiratory discomfort in asthma.

Methods:

Adults with asthma (n = 230) underwent methacholine (Mch) challenge. Anxiety and depression, asthma control, and quality of life were evaluated at study entry by using the Hospital Anxiety and Depression Scale, Asthma Control Test, and Asthma Quality of Life Questionnaire, respectively. Qualitative descriptors of breathlessness, dyspnea intensity (modified Borg scale and visual analog scale [VAS]), and other respiratory symptoms were evaluated before and after Mch challenge.

Results:

Patients were classified as neither anxiety nor depression (NAD), anxiety only, depression only (D), or both anxiety and depression (AD) according to the Hospital Anxiety and Depression Scale score. Asthma Control Test and Asthma Control Test, and Asthma Quality of Life Questionnaire scores were lowest in the AD group (both p < 0.001). VAS scores for dyspnea and wheezing before Mch challenge were highest in the AD group (both p < 0.05). The increase in the modified Borg scale score after Mch challenge was higher in the AD group (mean [standard deviation] 2.5 ± 2.0) than in the NAD (1.5 ± 1.5) and D (0.8 ± 0.9) groups (p = 0.006 and p = 0.003, respectively). Most descriptors of breathlessness were more prevalent in the anxiety only, D, and AD groups than in the NAD group. Multivariable logistic regression models indicated that anxiety increased the risk of dyspnea (odds ratio 1.10, p < 0.001 for the Borg score; odds ratio 3.84, p = 0.032 for the VAS score) but not for other respiratory symptoms.

Conclusions:

Anxiety but not depression was associated with greater perceived dyspnea intensity but not other measures of respiratory discomfort in individuals with asthma. Anxiety may shape the quality and intensity of dyspnea at a given respiratory load.