The Role of Mild Behavioral Impairment in the Clinical–Biological Continuum of Alzheimer′s Disease

Alzheimer’s disease has recently been redefined as a complex clinical–biological entity by the International Working Group (IWG), and while the cognitive symptoms associated with the disease progression have been thoroughly investigated, subtle behavioral changes that precede functional decline have been less systematically explored. Mild Behavioral Impairment has recently emerged and been operationalized with a dedicated checklist (MBI-C) to identify individuals presenting later-life persistent behavioral changes that might represent the first clinical signs related to an underlying neurodegenerative process. Here, we review current evidence supporting MBI as a promising clinical marker along the Alzheimer’s disease (AD) continuum since its preclinical stages, and we call for further research to investigate the potential added clinical value of a more structured, systematic assessment of behavioral changes in individuals at risk of progression. We outline that a structured MBI assessment could therefore be integrated first into future research diagnostic frameworks and, once validated in real-world settings, into routine clinical workups. Assessing MBI could then become a cost-effective, non-invasive tool aiding in distinguishing early neurodegenerative from primarily psychiatric disorders.