Southampton research reveals a clear link between ADHD and asthma

A University of Southampton researcher has carried out a major study aimed at assessing the relationship between the most common neurodevelopment disorder, Attention-Deficit/Hyperactivity Disorder (ADHD) and the most chronic condition in children, asthma.

The research, led by Dr Samuele Cortese at the University, has important implications for the clinical management of patients with both conditions and yields insights into the pathophysiology of ADHD, supporting a possible role of allergic mechanisms in ADHD.

The study, conducted by an international team of researchers, has been published in Lancet Psychiatry.

Dr Cortese, Associate Professor in Psychology and Medicine at the University of Southampton, said: “By combining a comprehensive analysis of available studies with a new large population-based study, we provided rigorous evidence supporting a significant association between ADHD and asthma.

“Mental health practitioners as well as clinicians involved in the care of respiratory diseases should be aware of this association, which might help to reduce delay in the diagnosis of both ADHD and asthma. Future research should aim to understand the mechanisms underlying this association, including possible common inflammatory alterations.”

To investigate the association between asthma and ADHD, researchers carried out an analysis of 49 pre-existing datasets, including a total of 210,363 participants with ADHD and 3,115,168 without, followed by a new population-based cohort study of 1,575,377 individuals (259,253 with asthma and 57,957 with ADHD) from the Swedish national registers.

Both the analysis of the 49 datasets and the population-based study concurred in highlighting a significant link between ADHD and asthma. According to the analysis of the 49 datasets, the prevalence of asthma was 16·9% in individuals with ADHD and 11·5% in those without. The prevalence of ADHD was 8·8% in individuals with asthma and 5·6% in those without.

Results were similar in the population-based study, where the prevalence of asthma was significantly higher in individuals with ADHD than in those without (24·8% vs 16·1%). Additionally, the prevalence of ADHD was significantly higher in individuals with asthma than in those without (5·5% vs 3·3%).

Awareness of the association between ADHD and asthma may lead ADHD specialists to promptly refer patients with early forms of asthma and, vice-versa, asthma specialists to promptly refer children with problems of inattention, hyperactivity, or impulsivity for appropriate assessment, reducing the diagnostic delay which is a concerning clinical and public health issue for both ADHD and asthma.

This is especially significant given that current guidelines for asthma do not mention ADHD, while available guidance on ADHD does not mention asthma.