As many as 50%–80% of children with Tourette's disorder
have some symptoms of attention
/hyperactivity disorder(ADHD), including a short attention span, restlessness, poor concentration, and diminished impulse control. On average, ADHD will manifest two and a half years before the tics appear. A dual diagnosis of ADHD and tic disorder is associated with more severe tics and greater social impairment than for tic disorder by itself.