BackgroundThis meta-epidemiological study seeks to further investigate the reciprocal relationship between allergic rhinitis (AR) and attention-deficit/hyperactivity disorder (ADHD). MethodsA comprehensive search of the databases was conducted up to March 3, 2024. We performed a synthesis and meta-analysis of odds ratios and their corresponding 95 % confidence intervals using Stata 14.0. Funnel plot analysis and Egger's regression test were utilized to assess potential publication bias. ResultsEighteen articles involving 4,289,444 participants were included. AR patients had an increased risk of developing ADHD (OR: 1.83; 95 % CI: 1.37–2.43), while ADHD patients were also more likely to have AR (OR: 1.38; 95 % CI: 1.11–1.72). Subgroup analysis indicated a predisposition of AR patients to autism spectrum disorder (OR: 1.34; 95 % CI: 0.86–1.0) and a higher risk of ADHD in cohort studies (OR: 1.90; 95 % CI: 1.26–2.88). Female AR patients were more likely to develop ADHD than males (OR: 1.86; 95 % CI: 1.43–2.43), and children aged ≤8 years with AR were at greater risk for ADHD compared to older children (OR: 1.75; 95 % CI: 1.14–2.69). ConclusionsThis meta-analysis confirms a bidirectional association between AR and ADHD, indicating that they are mutually independent risk factors.