It was found that parents of children with autism were almost twice as likely to have been hospitalized for a mental disorder, such as schizophrenia, than parents of other children.
"We are trying to determine whether autism is more common among families with other psychiatric disorders. Establishing an association between autism and other psychiatric disorders might enable future investigators to better focus on genetic and environmental factors that might be shared among these disorders," said study author Julie Daniels, Ph.D., an assistant professor in the UNC School of Public Health's epidemiology and maternal and child health departments.
"Earlier studies have shown a higher rate of psychiatric disorders in families of autistic children than in the general population. We wanted to see if the parents of autistic children were more likely to be diagnosed with mental disorders," she said.
She added: "Our research shows that mothers and fathers diagnosed with schizophrenia were about twice as likely to have a child diagnosed with autism. We also saw higher rates of depression and personality disorders among mothers, but not fathers.
Daniels also added that the results might also help researchers to look for causes of autism among related diseases, such as psychiatric disorders.
"It may eventually help identify opportunities to prevent or treat the disorder," she said.
The study involved the analysis of 1,237 children born between 1977 and 2003 who were diagnosed with autism before age 10, which were compared with 30,925 control subjects matched for gender, year of birth and hospital.
The large sample size enabled researchers to distinguish between psychiatric histories of mothers versus fathers in relation to autism. This link was present despite the timing of the parent's diagnosis relative to the child's diagnosis.
The study, "Parental psychiatric disorders associated with autism spectrum disorders in the offspring," appeared in the recent issue of the journal Pediatrics.