This study was based on a rare sample (patients diagnosed with dementia and bipolar affective disorder simultaneously) whose small number, 130 patients, poses statistical challenges. A history of bipolar disorder is associated with a significantly higher risk of dementia in older adults and has been associated with cognitive decline. Some studies investigating the risk of dementia and death in older people with bipolar disorder have concluded that bipolar disorder in senile age is associated with an increased risk of dementia (designated as greater neurocognitive impairment in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) and premature death. Bipolar disorder is a chronic psychiatric illness characterised by fluctuations in mood, with a relapsing and remitting course.The most common causes of dementia in individuals over the age of 65 are (1) Alzheimer's disease (2) vascular dementia and (3) vascular dementia and Alzheimer's type. Other diseases that account for around 10 per cent of the total include dementia with Lewy bodies; Pick's diseases; frontotemporal dementias.