Association Between Tic Aggravation and Methylphenidate in Youth With Attention-Deficit/Hyperactivity Disorder

OBJECTIVE: This study aimed to determine the tic aggravation event rate and cumulative incidence rate in the use of methylphenidate (MPH) treatment in attention-deficit/hyperactivity disorder (ADHD) and the factors that influence tic aggravation. METHODS: We conducted a retrospective chart review of children and adolescents aged between 6 to 15 years, who were diagnosed with ADHD from January 2017 to December 2019. A total of 121 subjects were included. The MPH dosage, psychiatric family history, comorbidity and past history of tics were assessed through chart review and the psychological examinations data were included. Collected data were analyzed using Cox regression and Kaplan-Meier survival analysis. RESULTS: Tic aggravation event rates without a past history of tics were 2.9% with MPH treatment in ADHD. Past history of tics, total MPH dosage and age were the factors associated with tic aggravation ([HR 21.46, p<0.001], [HR 0.94, p=0.023], [HR 0.79, p=0.021] for each). Cumulative incidence of tic aggravation was different between groups with or without past tic history. When treated with MPH, all tic aggravation appeared within approximately eight months but for subjects with a past history of tic, aggravation showed within approximately six months (p<0.001). CONCLUSION: Tic aggravation event rate was significantly low especially in the group without a past history of tics with the use of MPH in ADHD. However, a thorough assessment of past history of tics, and close monitoring during the first six-eight months of treatment with MPH is needed to avert a potential worsening of tics.