Is there just one gene involved in schizophrenia or in bipolar disorder?
No, there are most likely going to be several genes involved in these disorders. Different research groups may find different risk genes in their genetic studies. These genes will have different amounts of impact on risk for mental illness. In addition, it is possible that different groups of individuals may have different risk genes (i.e. an Irish person may have different genes that confer risk than one of Chinese descent.) Most scientists agree that, for individuals to develop schizophrenia or bipolar disorder, they must inherit several risk genes.
