Association of attentional shift and reversal learning to functional deficits in geriatric depression.

OBJECTIVE: The objective of this study is to examine the association between self-reported functional disability in depressed older adults and two types of executive function processes, attentional set shifting and reversal learning.
METHODS: Participants (N = 89) were aged 60 or over and enrolled in a naturalistic treatment study of major depressive disorder. Participants provided information on self-reported function in instrumental activities of daily living (IADL) and completed the Intra-Extra Dimensional Set Shift test (IED) from the Cambridge Neuropsychological Testing Automated Battery, which assesses intra-dimensional attentional shifts, extra-dimensional attentional shifts, and reversal learning. Participants were categorized by the presence or absence of IADL difficulties and compared on IED performance using bivariable and multivariable tests.
RESULTS: Participants who reported IADL difficulties had more errors in extra-dimensional attentional shifting and reversal learning, but intra-dimensional shift errors were not associated with IADLs. Only extra-dimensional shift errors were significant in multivariable models that controlled for age, sex, and depression severity.
CONCLUSIONS: Attentional shifting across categories (i.e., extra-dimensional) was most strongly associated with increased IADL difficulties among depressed older adults, which make interventions to improve flexible problem solving a potential target for reducing instrumental disability in this population.