Asthma and Anxiety Development in Australian Children and Adolescents

This study aimed to explore the relationship between the childhood asthma and anxiety in adolescence, specifically investigating whether anxiety precedes asthma or if asthma leads to development of anxiety.

Children in Australia were randomly selected using the Medicare database and enrolled in the Longitudinal Study of Australian Children. In this study, a cohort of 4386 children born in 2004 (B cohort) and another of 4983 children in kindergarten in 2004 (K cohort) were included. Data were analyzed at age 4 to 5 years and again at age 14 to 15 years, with 3127 from B cohort and 3537 from K cohort participating at age 14 to 15 years.

Asthma was defined by using primary caregiver responses to questions about diagnosis, medication use, and wheezing. To assess anxiety, parents completed the verified Strengths and Difficulties Questionnaire. Those above the 90th percentile were considered to have anxiety. Potential confounders such as sex, socioeconomic status, parental smoking, BMI, and ethnicity were also considered. Logistic regression models were used to evaluate the direction of the association between asthma and anxiety, using adjusted models for potential confounders. Statistical analysis included weights for primary sampling units and strata, and software R was used for analysis.

A significant portion of children with asthma but not anxiety at age 4 to 5 years developed anxiety by age 14 to 15 years (22.6% in the B cohort and 21.6% in the K cohort).

Children with asthma at 4 to 5 years old had a higher risk of anxiety at 14 to 15 years old compared with children without asthma (adjusted odds ratio 1.54 for B cohort, 1.87 for K cohort). In contrast, anxiety at baseline was not associated with risk of asthma at 14 to 15 years old. Development of anxiety was more likely in females. Both asthma and anxiety were associated with low socioeconomic status.

This study found a strong association between childhood asthma and development of anxiety in the following decade, suggesting a causal role of asthma in the development of anxiety.

There is a strong relationship between childhood asthma and adolescent anxiety. Possible contributing factors include stress related to symptoms and treatments of asthma. Physiologic mechanisms such as cytokinesis theory may also partially explain the association, as inflammatory cytokines cause a change in hormones in brain regions linked to anxiety development. Children with asthma may have an inherent disposition to this disorder. For high-risk patients, support systems should be investigated and implemented to target mental health. This may help prevent the development of anxiety or assist in diagnosis and symptom management.