Autism and schizophrenia share certain symptoms, such as a reduced capacity for communication and social interaction, Young says. But autism appears very early in life and schizophrenia generally doesn’t emerge until adulthood.
In addition, people with ASDs do not exhibit the psychotic symptoms characteristic of schizophrenia, which can include delusions, paranoia, and hallucinations. According to the latest version of the DSM, children with a diagnosis of Asperger’s syndrome or “pervasive developmental disorder not otherwise specified”—two types of ASD—cannot, by definition, also meet the criteria for schizophrenia.
The new study may spur doctors to look anew at the links between schizophrenia and ASDs, Sullivan says. In the future, he adds, a better understanding of the overlap between the two conditions could open the door to more precise diagnoses, and therefore more targeted treatment.
That scenario is still a long way off, however. Although scientists have identified a handful of genetic mutations that are linked to schizophrenia as well as autism, the role that specific genes and environmental factors play in the disorders is still largely unknown.
In the shorter term, renewed interest in the shared risk factors for autism and schizophrenia could lead to novel medication strategies, says Young, who is also the chair of an advisory board on brain-tissue research at Autism Speaks, an advocacy organization headquartered in New York City.
“I think these findings will encourage researchers to take a second look at drug therapies that have been shown to be effective in schizophrenia but have not been intensively studied for use in autism,” he says.