Causes
Although the exact cause of TS is unknown, researchers believe that is it likely caused by changes in certain areas of the brain as well as imbalances of the chemical messengers in the brain (such as dopamine, serotonin, and norepinephrine).
Genetics and family history also play a role. TS was once thought to be genetically inherited as a dominant trait, but recent studies show that the genetics of TS is much more complicated.
Children of parents with TS may not develop TS at all or may develop TS with varying degrees of severity. And some people who have TS have no family history of the condition. Boys born to a parent with TS are more likely than girls to have the condition. Girls, however, are more likely to have associated behavior conditions such as OCD.
Environmental factors may also play an important role in the development of TS.