The Effect of Depression in Instrumental Activities of Daily Living in Mild Cognitive Impairment: The mediating role of cognitive dysfuction

Abstract Background Geriatric depression can affect on decline of various cognitive functions including executive function and can lead to disabilities in instrumental activities of daily living (IADL). Decline in IADL was related to conversion to dementia even though there was no decline in screening tests such as MMSE. Therefore it is important to manage the factors affecting IADL. We examined the relationship between depression, cognitive dysfunction and IADL in mild cognitive impairment (MCI) to reveal the effect of depression on IADL. Method We recruited 132 patients with MCI who visited the Department of Neurology at Pusan National University Yangsan Hospital from March 2019 to June 2022. Using the Short‐Geriatric Depression Scale (S‐GDS: cuf‐off 8), these patients were divided into 64 depressed groups (mean age 75±6.7) and 68 non‐depressed groups (mean age: 71±8.1). To evaluate cognitive function, the Seoul Neuropsychological Screening Battery, which consists of five domains: attention, language functions, visuospatial functions, memory, and executive functions, was conducted. K‐IADL (Korean Instrumental Activities of Daily Living) was conducted to evaluate IADL. We investigated the mediation effect of cognitive functions between depression and IADL using mediation analysis. Result Depression and K‐IADL showed positive correlation (B = 0.023, p < 0.001). Mediation analysis of cognitive function between depression and IADL showed significant effect of executive function (B = ‐0.001, p = 0.019) and visuospatial function (B = ‐0.001, p = 0.045). Memory, language and attention domains had no significant mediation effect between depression and ADL. Conclusion In our study, depression related to decline in IADL, and not only the effects of depression but also mediation effects of executive and visuospatial dysfunction could affect IADL. In terms of IADL maintenance, it is necessary to actively manage the depressed mood of MCI patients.