The conundrum of the connection between severe psychiatric disorders and dementia.

Psychiatric disorders have been recognized as important risk factors for neurodegenerative diseases, especially dementia. The strength of association varies among different psychiatric conditions, being more pronounced in severe mental illnesses, i.e., schizophrenia and bipolar disorder. Multiple mechanisms seem to underlie this association, such as high prevalence of cardiovascular and other physical morbidities, poor lifestyle choices, and accelerated aging, including 'inflammaging'. They all represent opportunities for intervention, but it is still unclear whether current therapeutic approaches for psychiatric disorders can prevent the development of dementia. Other knowledge gaps include whether the risk of dementia applies to all patients with a certain condition, or if subgroups of patients are more vulnerable than others, whether different types of dementia are linked to specific psychiatric disorders.