Bipolar disorder and schizophrenia: not so distant relatives?

Bipolar disorder (BPD) and schizophrenia (SZ) may have some susceptibility genes in common, despite the fact that current nosology separates them into non-overlapping categories. The evidence for shared genetic factors includes epidemiologic characteristics, family studies and overlap in confirmed linkages. Review of these data indicates that there are five genomic regions which may represent shared genetic susceptibility of BPD and SZ. As the genes underlying these confirmed linkages are identified, the current nosology must be changed to reflect the new knowledge concerning the shared etiologies of BPD and SZ.