IADL functions, cognitive deficits, and severity of depression: a preliminary study

Despite the documented association of cognitive dysfunction with impairment in instrumental activities of daily living (IADLs) in geriatric depression, the relationship among deficits in distinct IADLs with severity of depression and specific cognitive impairments remains to be clarified. The authors examined the relationship of depression severity and the cognitive domains of attention, initiation/perseveration, construction, conceptualization, and memory to nine distinct IADLs.

The subjects were 105 nondemented elderly patients but with impairment in at least one IADL and a history or presence of major depression. Impairment in IADLs and severity of depression were assessed with the Philadelphia Multilevel Assessment Instrument (MAI) and the 24-item Hamilton Depression Rating Scale (Ham-D), respectively. Cognitive dysfunction was assessed with the Mini-Mental State Exam (MMSE) and the Mattis Dementia Rating Scale (DRS).

Six IADLs were influenced by impairment in at least one of the cognitive domains. Abnormal scores in initiation/perseveration, an aspect of executive dysfunction, was the cognitive impairment affecting most IADLs; it interfered with the ability to shop for groceries, prepare meals, take medicine, and manage money. Impairment in initiation/perseveration had a most prominent effect in the presence of depressive symptoms and affected shopping for groceries and preparing meals. Lack of interest and motivation, part of the depressive syndrome, compounded by behavioral abnormalities resulting from executive dysfunction, may account for this interaction.

These relationships may provide the background for developing interventions targeting functional deficits associated with specific cognitive dysfunctions and depression.