Are bipolar disorder and dementia linked?

Mental health and cognitive decline: Do they go hand in hand?

Bipolar disorder (BD) and dementia, two conditions often associated with cognitive decline, share some similarities yet present distinct differences.

Bipolar disorder, a mood disorder, causes shifts in a person's mood, energy, and behavior. It is characterized by episodes of mania and depression. Research suggests that both BD and dementia are associated with progressive cognitive decline, but the relationship between the two conditions is complex and more research is needed to determine the exact connection.

Depressive symptoms of BD that are not common with dementia include guilty ruminations, feelings of worthlessness, and suicidal thoughts. On the other hand, symptoms of dementia not typical of BD include repetitive motor behavior, apparent loss of knowledge of social norms, and lack of interest in sex.

Late-onset BD, which typically begins in older adults, has a couple of key differences from early-onset BD. Episodes may be more persistently depressive, and symptoms score lower on the Manic State Rating Scale. This form of BD can present differently in older adults, including more frequent episodes, less severe manic symptoms, and more severe depressive symptoms.

Similarities between late-onset BD and dementia include disinhibition, cognitive alterations, depressive symptoms, manic symptoms, apathy, anhedonia, lack of motivation, lack of interest, lack of energy, impaired concentration, irritability, pressured speech, impulsivity, psychomotor agitation, excessive jocularity or cheerfulness, and inappropriate social conduct or sexual behavior.

The similarities between the two conditions make diagnosis difficult. However, a healthcare professional can perform specific cognition and dementia tests to assess whether a person may have dementia.

Researchers do not yet fully understand the connection between BD and dementia, but a growing body of research suggests that BD may be a progressive condition associated with worsening cognitive decline over time. A study concluded that those with BD are around three times more likely to develop dementia, while another found a significant association between a history of BD and an increased risk of dementia in older adults.

It is important to note that if someone is in crisis and considering suicide or self-harm, help is available. In the US, the 988 Lifeline, Crisis Text Line, Befrienders Worldwide, and local emergency services are resources for those in need. If you're not in the same household, it is recommended to stay on the phone with them until help arrives. If you're calling on behalf of someone else, stay with them until help arrives.

In addition, BD is associated with cognitive impairments that may increase the risk of developing dementia, especially in older adults and those with a genetic predisposition. Lithium treatment at subtherapeutic levels might have beneficial cognitive effects in this context.

In conclusion, while BD and dementia share some similarities, they are distinct conditions with unique symptoms and risks. Further research is needed to fully understand the connection between the two conditions and to develop effective strategies for early detection and treatment.