Executive function, intellectual decline and daily living skills

Understanding the cognitive changes associated with compromised daily living skills in elderly individuals is important for making appropriate recommendations about the capacity for independent functioning. To this end, we retrospectively examined data from 92 elderly individuals presenting with cognitive decline who were administered measures of executive functioning, general intelligence, and daily living skills. Multiple regression analyses were used to examine the relationship between executive functioning and daily living skills, while controlling for age, depression, and either IQ decline or current IQ. Executive functioning accounted for additional variance in a broad range of daily living skills after controlling for IQ decline. When FSIQ was used in the regression model rather than IQ decline, executive functioning was no longer uniquely associated with daily living skills. Executive functions appear to be important for daily living skills until a critical threshold of low intellectual functioning is reached, reflecting the combined influence of premorbid ability and the extent of intellectual decline. Our results suggest that understanding the relative contribution of different cognitive domains to functional decline in elderly individuals should take into account general intellectual functioning and estimated decline, and that the initiation and/or persistence of self-directed cognitive processes may be important for adaptive daily functioning. These findings have implications for making more evidence-based recommendations about the capacity for independent living.