Executive dysfunction in Alzheimer's disease: association with neuropsychiatric symptoms and functional impairment

Relationships between measures of executive skills and neuropsychiatric and functional status were examined in a group of 31 patients with Alzheimer's disease. Deficits in four executive skills tests were significantly associated with the Agitation/Disinhibition factor score and Total Neuropsychiatric score on the Neurobehavioral Rating Scale, as well as the Activities subscore on the Blessed Dementia Scale. The majority of these associations remained significant after covariance for Mini-Mental State Examination scores. Executive dysfunction is associated with clinically relevant neuropsychiatric symptoms and functional impairment in Alzheimer's disease. These associations may be independent of other cognitive deficits such as memory, language, and visuospatial skills, and may not be appreciated on routine clinical evaluations. Executive skills deficits, neuropsychiatric symptoms, and functional disability may emerge from shared neurobiological mechanisms.