Objectives: A thorough examination of the relationship of asthma severity and control with symptoms of depression is needed to identify groups of asthmatics at high risk for poor disease control outcomes. This study examines the relationship of symptoms of depression with severity and control in a well-characterized cohort of asthmatics and healthy controls.
Methods: Depressive symptoms and quality of life were assessed using the Beck Depression Inventory. Disease control was measured by a composite index incorporating symptoms, activity limitation and rescue medication use.
Results: Individuals with asthma (n = 91) reported more symptoms of depression than controls (n = 36; p < 0.001). Those with severe asthma (n = 49) reported more symptoms of depression (p = 0.002) and poorer asthma control (p < 0.0001) than those with not severe asthma. Worse asthma control was associated with more depressive symptoms in severe (r = 0.46, p = 0.002) but not in not severe (r = 0.13, p = 0.40) asthmatics. The relationship of symptoms of depression among severe asthmatics was attenuated by disease control. Exploratory analyses identified specific disease symptom characteristics, as opposed to exacerbations, as associated with symptoms of depression.
Conclusions: Among individuals with severe asthma, increased symptom burden is positively associated with risk for co-morbid depression. These findings point to a need for regular mood disorder screenings and treatment referrals among this group. Further research is warranted to examine whether treatment of comorbid depression improves treatment adherence and asthma-related quality of life.