Researchers at Catania University, and University Tor Vergata, Rome, Italy studied the course of Tourette syndrome (TS) after 10 years follow-up in 100 children. Of the “pure TS” group (n=38), 58% were unchanged, whereas 42% changed to TS+OCD phenotype. Of the “TS+ADHD” group (n=48), 62% changed to pure TS, 35% to TS+OCD, and 2% to TS+ADHD+OCD. Medication was required in 65%. Patients with comorbid condition at onset had a more severe prognosis and lower quality of life scores. 
COMMENT. Patients with pure TS at onset have a favorable prognosis, whereas patients with TS and comorbid disorders, ADHD and OCD, are at risk of impaired quality of life. TS presents with a variety of clinical phenotypes that may change over time. Appropriate treatment of ADHD in children with TS may prevent behavioral problems in adulthood. Comorbidity with ADHD, occurring in 50% of TS patients, causes more disability than motor tics alone . Children with TS and ADHD have a 32% risk of learning disabilities.