Terao T, et al. - Performing a qualitative review of the relevant articles, researchers here focus on a particular group of patients whose diagnoses were changed from unipolar depression to bipolar disorder, and subsequently to dementia. Manic and/or hypomanic episodes are manifested by a substantial portion of patients with unipolar depression resulting in a change of diagnoses to bipolar disorder. Further, dementia develops in a substantial portion of bipolar patients. As per previous research, a correlation exists between genetic variants in the glycogen synthase kinase 3β (GSK-3β) gene and early onset of unipolar depression, a subset of which may be bipolar depression; three SNPs reported were rs334555, rs119258668, and rs11927974. Notably, an association of another promotor SNP (rs334558) of the GSK-3β gene with unipolar depression, bipolar disorders, and dementia is reported. Further, lithium, which is listed to inhibit GSK-3, is commonly admitted to be effective for bipolar disorder and recently proclaimed to be effective for dementia. These findings suggest the existence of a specific group of patients whose diagnoses longitudinally change from depression to bipolar disorder and eventually to dementia. GSK-3 seemed to be a common etiological factor in these diseases and in diagnostic conversions.