The association between tic medication therapy and psychiatric comorbidities among patients with Tourette syndrome: A national population-based study in Taiwan

Background: Tourette syndrome (TS) is often comorbid with attention deficit hyperactivity disorder, obsessive–compulsive disorder, and depression. Medications are the main treatment for TS. Relationships between TS medication therapy and psychiatric comorbidities remain unclear. This study explored the impacts of TS medication on the risk of psychiatric comorbidities using a nationally representative sample of TS in Taiwan. Methods: Data from National Health Insurance Research Database in Taiwan was used to identify 997,213 children and adolescents aged 6–18 years who had received a diagnosis of TS based on ICD-9-CM codes in 2000–2010. Cox's proportional hazard regression analysis was conducted to estimate the risk of comorbidities among subjects with and without tic medication therapy. Results: We found that in TS patients, a lower risk of psychiatric comorbidities occurred in the tic medication therapy group (p = 0.012) and the crude hazard ratio (HR) was 0.6 (95% confidence interval (CI) = 0.4–0.8, p < 0.001). After adjusting for potential confounders of gender, age, income, level of care, department visited, brain injury, and the number of suicide attempts, the risk of comorbidities was still significantly lower in the tic medication therapy group (adjusted HR = 0.5, 95% CI = 0.3–0.6, p < 0.001). Discussion: One limitation was that we did not include all mediations used to treat psychiatric comorbidities among TS patients. This study found the effectiveness of TS medications on improving psychiatric comorbidities. Conclusions: Compared to those without medication, medication therapy appears to have a benefit of decreasing the risk of psychiatric comorbidities. Strategies to improve medication regimens should be considered in clinical settings.