Depressive symptoms with cognitive dysfunction increase the risk of cognitive impairment: analysis of the Korean Longitudinal Study of Aging (KLoSA), 2006–2018

• Published in: International psychogeriatrics 2021-08, Vol.33 (8), p.791-801
• Main Author: Shin, Minyoung
• Format: Article
• Language: English
• Subjects: Aging; Cardiovascular disease; Cognitive ability; Cognitive impairment; Cohort analysis; Community; Dementia; Disease prevention; Geriatrics; Health care; Longitudinal studies; Mental depression; Mini-Mental State Examination; Older people; Original Research Article; Survival analysis; Symptoms
• ISSN: 1041-6102; 1741-203X
• DOI: 10.1017/S1041610220003622

Objectives:Geriatric depression complicates cognitive health in older adults. This study aims to investigate the impact of depressive symptoms on cognitive impairment in community-dwelling older adults, depending on whether cognitive dysfunction accompanied.Design:A community-based longitudinal cohort study.Setting:This study analyzed data from the Korean Longitudinal Study of Aging (KLoSA) from 2006 to 2018.Participants:Among 10,254 individuals who were registered in the KLoSA study, a total of 9119 subjects met the criteria, and 4547 subjects were included in the final analysis. The subjects were grouped into 4 categories based on depressive symptoms and cognitive dysfunction at baseline assessment: “normal control” (NC, n = 3341), “depression only” (Dep-only, n = 652), “cognitive dysfunction only” (CD-only, n = 393), and “depression with cognitive dysfunction” (Dep-CD, n = 161).Measurements:Cognitive impairment 10 years later was defined as K-MMSE scores below two percentile on demographically adjusted norms.Results:Ten-year survival, that is, not experiencing cognitive impairment, was 80 \[ \pm \,\]1% in NC group, 72 \[ \pm \] 2% in Dep-only group, 52 \[ \pm \] 3% in CD-only group, and 44 \[ \pm \] 5% in Dep-CD group. The hazard ratio (HR) of the Dep-only group (HR = 1.18, 95% CI, 0.97–1.43, n.s.) did not differ from that of the NC group, but the HR of the Dep-CD group was significantly higher (HR = 2.85, 95% CI, 2.23–3.66, p < 0.001) than the NC group. When the Dep-CD group was compared to the CD-only group, the HR was 1.13 (95% CI, 0.85–1.49, n.s.), which indicates that it did not significantly differ from the CD-only group.Conclusions:Our findings suggest that depressive symptoms with cognitive dysfunction are associated with a higher risk of cognitive impairment. Furthermore, cognitive dysfunction occurring with depressive symptoms is as much a risk for cognitive impairment as is pure cognitive dysfunction. Thus, healthcare providers should pay close attention to the community-dwelling elderly when depressive symptoms occur with cognitive dysfunction.