Neuropsychiatric symptoms as early manifestations of emergent dementia: Provisional diagnostic criteria for mild behavioral impairment

TLDR

Neuropsychiatric symptoms are common in dementia and mild cognitive impairment, and mild behavioral impairment has been proposed as a construct to identify individuals at increased risk of developing dementia even without cognitive symptoms. The authors propose new mild behavioral impairment criteria that incorporate mild cognitive impairment, extending prior definitions to provide a template for future validation studies. These criteria are developed by integrating MCI into the MBI framework and are intended to guide epidemiologic, neurobiological, treatment, and prevention research. Neuropsychiatric symptoms in mild cognitive impairment and in cognitively normal older adults predict higher risk of dementia or cognitive decline, and while mild behavioral impairment can co‑occur with MCI, the two constructs are distinct yet both signal increased dementia risk.

Abstract

Abstract Neuropsychiatric symptoms (NPS) are common in dementia and in predementia syndromes such as mild cognitive impairment (MCI). NPS in MCI confer a greater risk for conversion to dementia in comparison to MCI patients without NPS. NPS in older adults with normal cognition also confers a greater risk of cognitive decline in comparison to older adults without NPS. Mild behavioral impairment (MBI) has been proposed as a diagnostic construct aimed to identify patients with an increased risk of developing dementia, but who may or may not have cognitive symptoms. We propose criteria that include MCI in the MBI framework, in contrast to prior definitions of MBI. Although MBI and MCI can co‐occur, we suggest that they are different and that both portend a higher risk of dementia. These MBI criteria extend the previous literature in this area and will serve as a template for validation of the MBI construct from epidemiologic, neurobiological, treatment, and prevention perspectives.