Exploring the Relationship between Bipolar Disorder and Dementia: A Narrative Review

Abstract

Background: With an increasing recognition of cognitive impairments in patients with bipolar disorder (BD), there is a growing need to explore the underlying mechanisms that may link BD to dementia. Methods: A systematic search of PubMed and Google Scholar identified English-language articles from 2001 to 2023. MeSH terms targeted BD, dementia, and related factors, screening articles based on relevance to elucidate the relationship between BD and dementia. Results: The review highlighted the cognitive effects of commonly used BD medications, noting potential dementia risks with long-term benzodiazepine and anticonvulsant use, and neuroprotective effects of lithium. It also explored shared genetic variations and neurobiological pathways underlying both BD and dementia, such as the role of the glycogen synthase kinase 3β and accelerated brain aging processes. Neuroimaging studies provided insights into structural brain changes observed in both conditions, revealing grey and white matter integrity alterations. Additionally, the review addressed medical comorbidities, lifestyle factors, and challenges accessing medical care in individuals with BD as a potential link between the two disorders. Limitations: Gaps remain in understanding neurobiological mechanisms linking BD and dementia. Furthermore, there's insufficient evidence regarding the long-term impact of pharmacological treatments on dementia risk in BD patients, necessitating further investigation. Conclusions: Understanding the shared biological mechanisms between BD and dementia is crucial for advancing clinical practice and improving patient outcomes. Targeted interventions, such as optimizing medication regimens and addressing lifestyle factors, hold promise for reducing the risk of dementia in BD patients, highlighting the clinical relevance of this research.