Study compares traits of autism, schizophrenia

Autism spectrum disorder (ASD) and schizophrenia are distinct disorders with unique characteristics, but they share similarities in social dysfunction. For many years, this similarity resulted in confusion in diagnosis. Many young people with ASD were thought to have a childhood version of schizophrenia, said Dr. Noah Sasson, assistant professor in the UT Dallas School of Behavioral and Brain Sciences.

Sasson points out that clear differences exist between people diagnosed with schizophrenia and ASD. Symptoms of ASD can be seen from very early in life, while the onset of schizophrenia typically occurs in young adulthood. And individuals who have schizophrenia often experience hallucinations and delusional thoughts, which are far less common in individuals with ASD.

An overlapping problem for both clinical groups is a difficulty with social interaction. Both groups are known to be poor at recognizing social cues. They often have difficulty identifying emotion in other people, so their reactions may seem inappropriate. By not picking up on the subtle cues in interactions, adults with ASD or schizophrenia may alienate other people and have trouble making friends or getting along with classmates or co-workers.

Along with collaborators at Southern Methodist University, Sasson is conducting new research at the UT Dallas Callier Center for Communication Disorders that compares the basis for social interaction impairments between adults with ASD and adults with schizophrenia. He is attempting to understand the mechanisms that underlie their social limitations.

"Because the two disorders are different in so many ways, it is likely that the basis for their social impairments differs as well," he said. "Understanding these differences will be key for developing effective treatments. What works well for individuals with ASD might be very different than those with schizophrenia."

In previous research, Sasson and his colleagues used eye-tracking technology and found that neither adults with ASD nor adults with schizophrenia look at social information in the same way as those without either disorder. His colleagues also found that parts of the brain that process social information are underactive in those with ASD and schizophrenia. But the researchers have also found differences. Individuals with ASD do not spontaneously orient to emotional information, while individuals with schizophrenia do. While both groups show aspects of paranoia in social situations, Sasson and his colleagues are discovering that the root cause of the paranoia is different for each disorder.

"People with schizophrenia have a much higher likelihood than the general population to attribute ill will to others, and this is likely tied to their delusions," he said. "On the other hand, people with autism are more 'socially cynical.' They seem to be exhibiting fairly realistic responses to people as a result of the challenges they've faced in life because of their condition."

By differentiating between schizophrenia and autism, and by examining how patients react in social settings, Sasson said he hopes researchers can develop new ways to counteract the negative social experiences of patients. This could result in a profound improvement in their ability to navigate life successfully.