There can be confusion regarding the difference between autism and Tourette Syndrome. They are different types of disorders that do have similarities but considerable differences. Autism is a disorder characterized by repetitive behavior and impaired communication and social interaction. Whereas, Tourette Syndrome ("TS") is a disorder evident by the presence of multiple physical tics and at least one vocal tic, such as repetitive eye blinking or throat clearing.
Autism is one of the five pervasive developmental disorders, which include Asperger syndrome and Rett syndrome. These disorders are characterized by abnormalities in social interaction and communication, highly repetitive behavior, and severely restricted interests. TS is not in this group.
Tics are sudden, involuntary, repetitive, non–rhythmic body movements or vocalizations. Tics are also a feature of the autism spectrum of disorders, which also includes Asperger syndrome. This can make distinguishing between the Autism and TS disorders challenging for physicians. Furthermore, on rare occasion, a patient may have both autism and TS.
Signs and symptoms of autism typically occur prior to children with TS. The signs of autism begin in children before age three and diagnosis may occur at age two. Most children with TS are not diagnosed until age five or later. Autism symptoms also typically have longer lasting effects. Most children with autism continue to be affected by the disorder in adulthood, preventing them from living independently.
Autism also has significantly greater impact on communication that Tourette's. Nearly half of individuals with autism to not develop enough natural speech to communicate effectively. Individuals with TS do not have inability to communicate.
Some autistic individuals show unusual abilities in memorization, famously displayed in the 1988 movie Rain Man starring Dustin Hoffman and Tom Cruise. This savantism is not seen in TS. Many people with autism have superior skill in attention and perception, relative to the general population.
Other differences are that individuals with autism are much more likely to self–:injure than individuals with TS. Eye poking and skin picking are rare behaviors in a person with TS but more common with an autistic child. Autistic children also typically exhibit unusual eating behavior, which is not seen with TS.