Case series: Older age bipolar disorder with dementia

Most patients with bipolar disorder do not develop the symptoms until 18 years. With peak onset of 20–40 years, about 90% of cases are reported to have onset prior to age 50 years. Population-based surveys revealed a decrease in the prevalence of bipolar disorder with age, but 6–8% of all new cases of bipolar disorder developing in persons ≥60 years of age The elderly bipolar disorder patients often comorbid with dementia, presented many psychiatric symptoms. This condition is difficult to distinguish from overactivity, agitation, and excitation in behavior and psychological symptoms of dementia and delirium. Therefore, older age bipolar disorder is not well understood and are under- investigated. Herein, we presented three cases of older age bipolar disorder with dementia to discuss the possibility of biological overlaps between BD and dementia, as well as treatment options.