<b>Effect of comorbid allergic diseases on attention-deficit hyperactivity disorder symptoms and sleep</b>

Objective: To investigate the effect of comorbid allergic on symptoms and sleep in children with ADHD. Methods: This was a cross-sectional study, 222 ADHD children (aged 6-14 years) were enrolled in, of whom 93 had allergic diseases and 129 without allergic diseases. Collected all ADHD symptom severity and functional impairment scales, including: Swanson, Nolan and Pelham (SNAP) scale, Integrated Visual and Auditory Continuous Performance Test (IVA-CPT), Conners Parents Symptom questionnaire (PSQ) and Weiss Functional Impairment Rating Scale-Parent Form (WFIRS-P). Every guardian of children diagnosed with ADHD is required to complete the Children’s Sleep Habits Questionnaire (CSHQ). Results: Compared to ADHD children without allergic diseases, we observed significantly higher hyperactivity and impulsivity scores on the SNAP-IV, higher hyperactivity index and impulsivity index on the PSQ, and higher risky activities on the WFIRS-P in ADHD children with comorbid allergic diseases (all p&lt; 0.05). CSHQ total score and sleep disordered breathing were particularly prominent in ADHD children with comorbid allergic diseases (all p&lt; 0.05), and changes in CSHQ correlate with ADHD symptoms and functional impairment. Further analyses revealed that ADHD symptoms and sleep did not worsen with increasing number of comorbid allergic diseases (all p&gt; 0.05). The primary influence on ADHD symptoms and sleep was the type of allergic diseases, where food allergies predominantly influence ADHD symptoms, including attention deficit disorder and hyperactivity disorder (all p&lt; 0.05); allergic rhinitis notably impacts parasomnias, sleep disordered breathing (all p&lt; 0.05); and allergic asthma significantly affects sleep anxiety, daytime sleepiness, and sleep disordered breathing in children with ADHD (all p&lt; 0.05). Conclusion: The presence of comorbid allergic diseases affects both the hyperactivity and impulsivity symptoms of ADHD and sleep disordered breathing, predominantly influenced by the type of the allergic diseases.