Autism Linked to Bipolar Disorder, Schizophrenia

Autism rates higher in families with a history of bipolar disorder and schizophrenia

(RxWiki News) Research is looking for ways to understand which children are at risk for autism spectrum disorders (ASD), because knowing the risk factors can help with early detection.

A new study found that ASD was one and a half to three times more likely in people who had a parent or sibling with either schizophrenia or bipolar disorder.

These disorders may have a genetic link, and this study highlights the importance of providing an accurate family history. 

"Tell your doctor about any mental health history."

A study led by Patrick F. Sullivan, MD, of the University of North Carolina at Chapel Hill, with researchers in Sweden and Israel, looked at the relationship of schizophrenia and bipolar disorder with ASD.

In all three phases of the study, they looked at patient records.

First, they looked at 25,432 families that were part of the Swedish national registry. They looked at the people with ASD to see if parents or siblings had either schizophrenia or bipolar disorder.

In the second phase, they looked at the parents of 4982 people with ASD that were seen at a city clinic in Sweden.  In the final phase, they looked at the siblings of 386 people in the Israeli military who had ASD.

Together, they found that, in the Swedish population, ASD was 2.9 times more likely when a parent had schizophrenia, and was 2.6 times more likely when a sibling had schizophrenia.

When a parent had bipolar disorder, ASD was 1.9 times more likely, and a sibling with bipolar disorder increased the odds of ASD 2.6 times.

In the Israeli military, ASD was 12 times more likely when a sibling had schizophrenia.

The authors reported that the very high odds in the Israeli sample was likely due to the fact that the rates of early onset schizophrenia were high in that sample. Early onset schizophrenia has a stronger genetic link and is often seen in siblings.

The authors said in their report, “The presence of schizophrenia or bipolar disorder in first-degree relatives was a consistent and significant risk factor for ASD in all 3 samples.”

They concluded that some common environmental factor or genetic factor is likely to link these disorders.

The research report was published in July in the Archives of General Psychiatry. The study was funded by The Swedish Council for Working Life and Social Research, the Swedish Research Council, and the Beatrice and Samuel A. Seaver Foundation.

Authors report no conflicts of interest.

Review Date: 
July 9, 2012