For many years, mental health researchers have noted that social difficulties and shyness among children with autism spectrum disorder (ASD) often resemble symptoms of social withdrawal, a trait of schizophrenia. Now, new findings, published in the journal Schizophrenia Research, suggest the two mental disorders may share the same genetic root, Scientific American reports. 

Previous research has shown that people with autism are more likely to be diagnosed with a psychotic condition, such as schizophrenia, and vice versa. According to some mental health experts, this happens because doctors often misdiagnose people with a psychotic condition as having the developmental disorder. 

For this recent study, researchers at the Emory Autism Center in Atlanta assessed 89 adolescents with a genetic disorder known as 22q11.2 deletion syndrome, a mutation linked with a 25-fold increase in the risk of developing a psychotic condition, as well as an increased risk of autism.

At the beginning of the study, scientists diagnosed 52 of the teenagers with ASD. When the research team reevaluated participants two to six years later, they discovered that nine of the 52 teens with autism had also been diagnosed with a psychotic condition, and 10 of the 37 participants without autism had developed some form of psychosis. 

Scientists noted that although the new findings suggested that ASD and schizophrenia might be different outcomes of the same genetic disorder, individuals diagnosed with autism didn’t automatically face the risk of developing a psychosis. 

If there is a relationship between ASD and schizophrenia, “that can only be a very small, very negligible effect,” said Jacob Vorstman, PhD, an assistant professor of psychiatry and genetics at the University Medical Center Utrecht in the Netherlands and the study’s lead investigator.

Next, the researchers will begin pooling genetic and brain imaging data with collaborators across Europe and the United States to further investigate how the genetic mutation might produce two independent conditions. The scientists also urged other mental health researchers to replicate their work in larger samples to help further explore the link.

Click here to learn more about how changes in a person’s genes can increase their risk of developing schizophrenia and other mental illnesses.