Asthma affects approximately 4.4 million U.S. children,1 and accounts for 2.9 million annual pediatric visits.2 A disproportionate number of children and adolescents with asthma are affected by depression and anxiety, compared to non-asthmatic controls.3 Asthma in youth is also linked with increased risk of suicide.4
In their article entitled “Asthma and Mental Health Among Youth: Etiology, Current Knowledge, and Future Directions,” Goodwin et al review the relationship between asthma and psychiatric disorders in youth, analyzing psychosocial and biochemical factors of causality, cigarette smoking, and medication side effects. [Goodwin et al, 2012]
Having a chronic health condition with distressing and disruptive symptoms can result in feelings of hopelessness and discouragement, leading to depression, the authors suggest. Additionally, living with a life-threatening condition might result in anxiety or post-traumatic stress. There may also be an indirect connection: Depression has been associated with poor medication adherence in an array of chronic diseases, and this may be the case in asthma as well.
Family dysfunction (eg, parental criticism or family conflict) is known to play a significant role in childhood asthma and general mental health problems in youth.6 The authors note that optimal understanding of childhood asthma and depression might be achieved using a combination of family and psychobiological mechanisms.
The Role of Cigarette Smoking
The authors state that cigarette smoking plays a role in asthma in patients of all ages. There is an association between smoking exposure and conduct disorders, attention-deficit/hyperactivity disorder, and depressive and anxiety disorders in children and adolescents. Youth who are depressed and/or anxious are more likely to smoke; smoking, in turn, can trigger or exacerbate asthma. However, the authors add, the exact pathways through which smoking, mental health problems, and asthma reciprocally influence one another remain unclear.
Asthma is known to be an inflammatory disease in which the airways are infiltrated by T-helper cells, leading to the release of proinflammatory cytokines.7 There is also association between depression and inflammation.8 The authors list four pathways through which localized inflammation or peripheral circulating cytokines might influence brain signaling and induce depression—direct stimulation of primary afferent nerves, stimulation of Toll-like receptors on macrophages residing in the circumventricular organs; cytokine transporters on the blood-brain barrier, and IL-1 receptors on cells within the brain venules. [Goodwin et al, 2012]
Given a common link between depression and asthma and a link between both depression and asthma and inflammation, it is possible that inflammation may play a mediating role in the relationship between depression and asthma.