By Sarah Carnvek
New Israeli research shows that autism spectrum disorder (ASD) appears to share similar roots with mental illnesses including schizophrenia and bipolar disorder. Sheba Medical Center Chief of Psychiatry Dr. Mark Weiser has revealed a genetic connection between autism and schizophrenia – representing a heightened risk within families.
Studying extensive databases in Israel and Sweden, Weiser's team found that people with a schizophrenic sibling are 12 times more likely to have autism than those with no schizophrenia in the family. The presence of bipolar disorder in a sibling showed a similar pattern of association, but to a lesser degree.
The researchers used three data sets, one in Israel and two in Sweden, to determine the familial connection between schizophrenia and autism. The Israeli database, used under the auspices of the ethics committees of both the Sheba Medical Center and the Israel Defense Forces, included anonymous information about more than a million soldiers, including those with schizophrenia and ASD.
"We found the same results in all three data sets," Weiser says, noting that the ability to replicate the findings across these extensive databases is what makes this study so significant.
1 in 88 children
ASD, a category that includes autism, Asperger’s syndrome and pervasive developmental disorder, is characterized by difficulty with social interaction and communication, or repetitive behaviors.
The US Centers for Disease Control and Management says that one in 88 children in the United States is somewhere on the autism spectrum — a 10-fold increase in the last four decades.
At first glance, schizophrenia and autism look like completely different phenomena, Weiser says. But closer inspection reveals many common traits, including social and cognitive dysfunction and a decreased ability to lead normal lives and function in the real world.
"The phenomena of schizophrenia and autism are actually quite similar and this shows it might be genetic," says Weiser, who also is chairman of the psychiatry department at Tel Aviv University’s Sackler Faculty of Medicine.
The study -- done in collaboration with researchers at the University of North Carolina, Karolinska Institute in Sweden, Kings College London, and the Israeli Defense Force Medical Corps -- is considered a scientific leap forward. Published in the Archives of General Psychiatry, the results could provide new insight on the genetics of these disorders.
"My research group and the field in general are trying to understand what the biology is behind the findings," says Weiser. "The results will help scientists better understand the genetics of mental illness."
Knowing this genetic connection could be a missing link, Weiser adds. It also provides a fresh direction for study as the researchers take their findings to a clinical level. For now, Weiser says, the findings should not influence the way that doctors treat patients with either condition.