With the progressive aging of the population, late onset disorders are assuming an increasingly relevant role in Psychiatry. Our aim is to conduct a literature review regarding the main areas of interest concerning 'late onset Bipolar Disorder (BD)”.

A literature review, based on a PubMed research, takes stock of the studies that have investigated this subject in the latest years.

We will address the essential aspects of this clinical entity, namely its prevalence, clinical features and treatment. Special focus will be given to some questions that have been subject of debate in recent years. The results of early clinical investigations suggested that cases of BD with onset in later life were more often related with 'organic’ causes. Consequently some authors consider it a simple secondary affective disorder while others claim it has an unequivocal place in the bipolar spectrum. Nevertheless, recent studies emphasize its close association with dementia, postulating it as prodromal state or a risk factor for the latest. It has been also proposed that it may represent an expression of attenuated genetic vulnerability for bipolarity that is triggered or unmasked by a neurodegenerative process. In spite of the different attempts to understand and clarify the disorder, the available evidence, considering the various issues, was found to be sparse and variable.

Late onset BD remains a complex and relatively understudied disorder. Although no final conclusions can be drawn, the current theories point out an important association with neurodegenerative processes. It is undoubtedly a subject that deserves further investigation