Background: Asthma is a common, chronic disease that can have a negative impact on patients. Although there have been advances in the treatment and understanding of its pathology, most patients with asthma do not adequately manage the disease. Increased bronchodilator use, functional impairment, symptom exacerbation, and reduced pulmonary function are characteristics of poor control. Managing asthma depends on behavioral factors (e.g., treatment adherence, self-monitoring), which may be negatively influenced by chronic negative mood states. Other studies have shown that psychiatric disorders, especially depressive and anxiety disorders, are approximately six times more prevalent in patients with asthma compared with the general population. However, the impact these chronic negative mood states can have on asthma control and quality of life has not been studied. Lavoie and colleagues assessed the effects of depressive and anxiety disorders on asthma control and quality of life.

The Study: A consecutive sample of adult patients treated at an asthma clinic was enrolled. Patients were excluded if they had comorbidities that could negatively impact their asthma, such as chronic obstructive pulmonary disease, the presence of a severe psychological disorder, or a history of substance abuse. Sociodemographic information and the patient's medical history were evaluated, including the frequency of rescue bronchodilator use and the patient's alcohol consumption within the previous week. This was followed by a structured psychiatric interview to detect the most common disorders listed in the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV). The patients also completed an Asthma Control Questionnaire and an Asthma Quality of Life Questionnaire during the visit, then underwent spirometry to measure pulmonary function.

Results: Of the 504 patients included in the study, 31 percent met the criteria for one or more psychiatric disorders. Eight percent had only a depressive disorder, 12 percent had only an anxiety disorder, and 11 percent had both types of disorders. Patients who had only a depressive disorder had significantly worse control of their asthma compared with those who did not have a psychiatric disorder or those with only a anxiety disorder. This result was independent of age, sex, or the severity of the patient's asthma. Depressive and anxiety disorders had a significant negative impact on the Asthma Quality of Life Questionnaire. Those with a depressive disorder had score differences of 0.64 when compared with those without the disorder, which was considered to be clinically significant. Patients with an anxiety disorder tended to use their bronchodilators more often compared with patients without an anxiety disorder; however, there were no such effects for having a depressive disorder.

Conclusion: Asthma patients with depressive disorders had less asthma control compared with those without a psychiatric disorder or those with an anxiety disorder. However, depressive and anxiety disorders had a significant negative impact on the quality of life for patients with asthma. Therefore, when evaluating asthma control, physicians should include an assessment for chronic negative mood states.