In knockout mice, it has consistently been demonstrated that lacking an OGG1 repair system leads to increased accumulation of oxidative DNA lesions.39 Animal studies further suggest that OGG1 deficiency could increase susceptibility to neurodegeneration under conditions of increased oxidative stress.40 Accumulation of oxidatively generated DNA damage has been associated with cardiovascular disease41 and diabetes,42 which are also associated with bipolar disorder. This evidence concerns the gene OGG1 and bipolar disorder.