Relationships between functional decline, cognition and neuropsychiatric symptoms across normal aging, mild cognitive impairment and dementia.

Introduction. Correlations between cognition, functional decline and neuropsychiatric symptoms (NPS) are extensively investigated in patients with Alzheimer's disease (AD), but few studies are conducted in mild cognitive impairment (MCI). Furthermore, limitations in activities of daily living (ADL) are traditionally measured on the level of instrument ADL (i-ADL), while, in MCI, subtle changes in advanced ADL (a-ADL), defined as high level activities, might appear before i-ADL declines. This study aimed to explore correlation between cognition, NPS and a-ADL.

Methods. 50 cognitive healthy controls (mean age= 79.5 ±5.1) 48 patients with MCI (mean age= 80.4 ±4.7) and 45 patients with mild AD (mean age=80.7 ±5.1) were recruited in a Geriatric Day Hospital. Cognitive functioning was measured using the Mini Mental State Examination and Cambridge Examination for Mental Disorders of the Elderly; NPS with the Neuropsychiatric Inventory Questionnaire and a-ADL using the a-ADL tool.

Results. Significant differences were observed between groups for a-ADL and cognitive measures, not for NPS. For the sample as a whole, significant correlations were found for: a-ADL and cognition (-.171
Conclusions. Cognitive and functional decline and NPS might constitute an important early sign of mild cognitive disorders and should be incorporated in diagnostic work. In addition, this study confirms the usefulness of the a-ADL concept.