Tourette syndrome is characterized by motor and vocal tics, with a prepubertal age of onset, a waxing and waning course, and improvement in symptoms in adulthood.
Several studies have shown that Clonidine, an α (2)-adrenoceptor agonist, is effective in relieving tics, and the mechanism of action is thought to be linked to clonidine's effect on inhibitory learning resulting from reduced noradrenergic activity.