Autism spectrum disorders (ASD) are classified as neurological developmental disorders. Several studies have been carried out to find a candidate biomarker linked to the development of these disorders, but until recently none was known. Findings from a relatively new study suggest suggest that ASD, schizophrenia, and bipolar disorder share etiologic risk factors. The results were very consistent in large samples from several different countries (e.g., Sweden, Israel) and led researchers to believe that autism and schizophrenia are more similar than had been previously thought.
1. The presence of schizophrenia in parents was associated with an almost three times increased risk for autism spectrum disorders (ASDs) in groups from both Stockholm and all of Sweden.
2. The risk of an autism spectrum disorder may be higher among people whose parents or siblings have been diagnosed with schizophrenia or bipolar disorder.
3. Schizophrenia in a sibling was associated with roughly 2.5 times the risk for autism in the Swedish national group and a 12 times greater risk in a sample of Israeli military conscripts. Bipolar disorder showed a similar pattern of association but of a lesser magnitude.