Since baseline executive dysfunction predicts worsening Instrumental Activities of Daily Living (i-ADL) over time and progression to Alzheimer's Disease (AD), we aimed to analyze the role of neuropsychological variables to outline which factors can contribute to functional impairment. Specific attention to executive functions (EFs) has been given.
A total of 144 subjects complaining of different cognitive deficits – ranging from “MCI likely due to AD” to “mild AD patients” – underwent an overall neuropsychological assessment. The Behavioral Assessment of the Dysexecutive Syndrome was used to analyze EFs. We conducted multiple linear regression analyses to study whether the level of independent living skills – assessed with the Lawton-scale – could be associated with cognitive and behavioral measurements.
We found a significant association between i-ADL and specific EFs measured by Rule Shift Cards (p = 0.04) and Modified Six Elements (p = 0.02). Moreover, considering i-ADL scores, we observed an involvement of mood changes and a reduced awareness of deficits in terms of Hamilton Depression Rating Scale (p = 0.02) and Awareness of Deficit Questionnaire – Dementia scale (p < 0.0001), respectively.
Our results suggest the importance of considering the association between a reduction in i-ADL and executive dysfunction in patients who have AD etiopathology, for which the ability to inhibit a response, self-monitoring, set-shifting and mood deflection play a key role. Besides, no straightforward associations between i-ADL scores and global cognition, memory, language comprehension, attention, and perspective taking abilities were found.