Associations between attention-deficit/hyperactivity disorder and allergic diseases: a two-sample Mendelian...

Area of Science:

• Genetics
• Psychiatry
• Immunology

Background:

• Observational studies suggest a link between attention-deficit/hyperactivity disorder (ADHD) and allergic diseases, but findings are inconsistent.
• The potential causal relationship between ADHD and various allergic conditions remains debated.

Purpose of the Study:

• To investigate the potential causal relationship between attention-deficit/hyperactivity disorder (ADHD) and allergic asthma, allergic rhinitis, pollen allergy, allergic urticaria, and allergic conjunctivitis.
• Utilize the two-sample Mendelian Randomization (MR) approach to assess causality.

Main Methods:

• Employed a two-sample Mendelian Randomization (MR) study design.
• Utilized summary statistics from large-scale Genome-Wide Association Studies (GWAS) for ADHD and allergic diseases.
• Applied multiple MR methods including Inverse Variance Weighted (IVW), MR-Egger, and Weighted Median, with sensitivity analyses to ensure robustness.

Main Results:

• The IVW method suggested a potential slight increase in allergic asthma risk associated with ADHD (OR=1.0612, p=0.0039).
• However, other MR methods (MR-Egger, Weighted Median) did not find a significant causal effect of ADHD on allergic asthma.
• No significant causal evidence was found for the association between ADHD and allergic rhinitis, pollen allergy, allergic urticaria, or allergic conjunctivitis.

Conclusions:

• The findings do not provide strong evidence that ADHD causally increases the incidence of allergic diseases.
• Further large-scale Mendelian Randomization studies or randomized controlled trials are warranted to clarify the relationship between ADHD and allergic conditions.