Around one in five children with Tourette syndrome, a neurological disorder characterized by involuntary movements and vocalizations, met criteria for autism in a study headed by UC San Francisco. But this prevalence may be more a reflection of similarity in symptoms than actual autism, according to the study’s researchers.
Researchers tested 535 children and adults with Tourette’s for autism, using a self-reporting test called the Social Responsiveness Scale. Among the 294 children tested, 22.8 percent reached the cutoff for autism, versus 8.7 percent of the 241 adults. In contrast, autism is estimated to affect between 0.3 and 2.9 percent of the general population, according to studies cited in the paper.
The Social Responsiveness Scale Second Edition is a 65-item quantitative measure of autism symptoms that assesses the ability to engage in “emotionally appropriate reciprocal social interactions.” It evaluates levels of social awareness, social cognition, social communication, social motivation, and restrictive interests and repetitive behavior. Its threshold for autism compares favorably with the diagnostic gold standard, the Autism Diagnostic Interview, the researchers noted.