Association between atopic dermatitis and attention deficit hyperactivity disorder in US children and adults

Background Atopic dermatitis (AD) is associated with chronic itch, allergic disease and sleep disturbance, all of which might increase the risk of attention deficit (hyperactivity) disorder (ADD/ADHD). Previous analyses have found a consistent association between AD and ADD/ADHD, although the underlying factors contributing to such an association remain underexplored. Additionally, the relationship has been underexplored in adults. Objectives To determine if childhood and adult AD and AD severity are associated with ADD/ADHD and to delineate the factors contributing to such an association. Methods We analysed data on 354 416 children aged 2-17 years and 34 613 adults age 18+ years from 19 U.S. population-based surveys, including the National Health Interview Survey 1997-2013 and the National Survey of Children's Health 2003/4 and 2007/8. Results In multivariate models adjusting for age, sex, sociodemographics, allergic disease and healthcare utilization, AD was associated with ADD/ADHD in both children [adjusted odds ratio (95% confidence interval), 1.14 (1.03-1.26)] and adults [1.61 (1.25-2.06)]. Children with both severe AD and only 0-3 nights of adequate sleep per week had much higher odds of ADD/ADHD [16.83 (7.02-40.33)] than those with 0-3 nights of adequate sleep per week [1.83 (1.47-2.26)] or mild-moderate AD alone [1.56 (1.22-1.99)]. AD was most strongly associated with severe ADHD. AD unaccompanied by other allergic disease was also associated with increased risk of ADD/ADHD in children. Among children with AD, history of anaemia, headaches and obesity were associated with even higher odds of ADD/ADHD. Asthma, insomnia and headaches increased the odds of ADHD in adults with AD, although underweight body mass index was protective. Conclusions Atopic dermatitis is associated with increased odds of ADD/ADHD in adults and children. Several factors increase the risk of ADHD in adults and children with AD.