"The pattern of dysregulation was similar in the prefrontal cortex for both illnesses and pointed to key processes. Part of the set of core genes could be explained by medication responses; however most of these core genes did not appear to be correlated to medication response," said Dr. Ling Shao of the university's School of Medicine, who conducted the research with his colleague Marquis Vawter.
The researchers have reported their findings in the journal Biological Psychiatry.
Dr. John H. Krystal, Editor of Biological Psychiatry, says: "The new findings by Drs. Shao and Vawter provide evidence that there are a large number of genes that show a similar pattern of abnormal regulation in their sample of post-mortem brain tissue from individuals who had been diagnosed with schizophrenia or bipolar disorder. This overlap could provide insight into the neurobiology of both disorders."
The researchers believe that understanding of the neurobiology related to the shared genes may lead to the discovery of common brain mechanisms that may guide the identification of new and more effective treatments.
In their study report, the researchers also refer to recent discussions that have focused on considering schizophrenia and bipolar disorder as a single illness viewed along a continuum of mood and psychotic symptoms.
"We have traditionally treated these diagnoses as unrelated conditions even though many of the same medications, such as antipsychotic medications, are used to treat both conditions," notes Dr. Krystal.