Having a parent with psychiatric problems doubles a child's odds of being autistic, researchers said in a study released on Monday.

Doctors found that rates of autism rose substantially if parents had suffered schizophrenia, depression or a range of other personality and psychiatric disorders.

"Our research shows that mothers and fathers diagnosed with schizophrenia were about twice as likely to have a child diagnosed with autism," said Julie Daniels of the University of North Carolina, Chapel Hill, who worked on the study published in the May issue of Pediatrics.

"We also saw higher rates of depression and personality disorders among mothers, but not fathers," she said in a statement.

Researchers, led by Julie Daniels at the University of North Carolina at Chapel Hill, examined the medical records of 1,237 children in Sweden born between 1977 and 2003 who were diagnosed with autism before the age of 10. They were compared with families of nearly 31,000 children who did not have autism.

The study confirms previous, smaller studies that found that psychiatric disorders were more common among blood relations of people with autism. A strong genetic component is suspected for autism, a developmental disorder.

"This study might help us pinpoint some more genetic ties to more cases [of autism]," added Daniels.

(Agencies via Xinhua News Agency May 7, 2008)