Tic Disorders, Anti-Tic Medications, and Risk of Atopy.

Objective: To clarify patterns of comorbid atopic disorders in children with tic disorders compared to controls, and to evaluate whether medications commonly used for treatment of tics and attention deficit hyperactivity disorder (ADHD) are associated with differing risks of atopy. Background: Inflammatory mechanisms are increasingly recognized as playing a role in a range of neuropsychiatric disorders. The association between tic disorders, ADHD, obsessive-compulsive disorder (OCD) and atopic disorders is uncertain. Methods: We performed a retrospective cohort study using the global electronic health records database TriNetX. Using odds ratios, we compared the risk of atopy in children with tic disorder (n = 4508), ADHD (n = 83,569), and/or OCD (n = 1555) to controls (n = 758 290). To analyze the risk of developing atopy with use of different medications commonly prescribed to treat tics and ADHD, we performed a separate analysis including children with tic disorder, ADHD, and/or OCD who had initiated treatment with one of these medications. Binary logistic regression controlling for age and sex was used to calculate odds ratios. Results: Children with tic disorder, ADHD, or OCD were more likely than controls to have comorbid atopy. Children who had taken clonidine, guanfacine, methylphenidate, or dexmethylphenidate were more likely to develop an atopic disorder than controls. Conclusions: Our study suggests a link between atopic disorders and tic disorders, ADHD, and OCD. Although the underlying mechanism for this association remains unclear, medication use may play a role.