Washington : Schizophrenia or bipolar disorder seen in parents or siblings is associated with an increased risk of autism spectrum disorder (ASD), according to a team of researchers.
Avi Reichenberg, PhD, previously a Visiting Professor and now a new faculty member at the Seaver Autism Center and the Department of Psychiatry at Mount Sinai School of Medicine, and colleagues, used population registers from Sweden and Israel to examine whether a family history of schizophrenia, bipolar disorder, or both, were risk factors for ASD.
“Our findings indicate that ASD, schizophrenia and bipolar disorders share etiologic risk factors. Future research could usefully attempt to discern risk factors common to these disorders,” the researchers said.
Dr Reichenberg said, “These potentially shared etiologic risk factors could be genetic, or could also represent environmental factors. These findings are also important because if ASD, schizophrenia and bipolar disorder have some common causes, they may be more similar than we currently understand. This may change how researchers and clinicians think about these disorders”
Researchers conducted a case-control evaluation of histories of schizophrenia or bipolar disorder in first-degree relatives of the patients who met the criteria for ASD from three group samples. Two groups were in Sweden and the third group consisted of recruits to military service in Israel.
The study showed the presence of schizophrenia in parents was associated with an almost three-fold increased risk for ASD in a Swedish national group sample and a Stockholm County, Sweden, group.
Schizophrenia in a sibling also was associated with an increased risk for ASD in the Swedish national group and the Israeli conscription group. Bipolar disorder showed a similar pattern of association but to a lesser degree.
Archives of General Psychiatry published the study online on Monday, July 2.