Late-life depression, subjective cognitive decline, and their additive risk in incidence of dementia: A nationwide longitudinal study.

Sheng-Min Wang,Yoo Hyun Um,Dong-Woo Kang,Kyung-Do Han,Chang-Uk Lee,Hyun Kook Lim,Nak-Young Kim,Hae-Ran Na,Simone Reppermund

doi:10.1371/journal.pone.0254639

Abstract

ObjectiveLate-life depression and subjective cognitive decline (SCD) are significant risk factors for dementia. However, studies with a large sample size are needed to clarify their independent and combined risks for subsequent dementia.MethodsThis nationwide population-based cohort study included all individuals aged 66 years who participated in the National Screening Program between 2009 and 2013 (N = 939,099). Subjects were followed from the day they underwent screening to the diagnosis of dementia, death, or the last follow-up day (December 31, 2017).ResultsDepressive symptom presentation, recent depressive disorder, and SCD independently increased dementia incidence with adjusted hazard ratio (aHR) of 1.286 (95% CI:1.255–1.318), 1.697 (95% CI:1.621–1.776), and 1.748 (95% CI: 689–1.808) respectively. Subjects having both SCD and depression had a higher risk (aHR = 2.466, 95% CI:2.383–2.551) of dementia than having depression (aHR = 1.402, 95% CI:1.364–1.441) or SCD (aHR = 1.748, 95% CI:1.689–1.808) alone.ConclusionsDepressive symptoms, depressive disorder, and SCD are independent risk factors for dementia. Co-occurring depression and SCD have an additive effect on the risk of dementia; thus, early intervention and close follow up are necessary for patients with co-occurring SCD and depression.

Highlights

Dementia is a neurodegenerative disorder characterized by progressive cognitive impairment, behavioral disturbances, and a loss of daily function [1]
Depressive symptom presentation, recent depressive disorder, and subjective cognitive decline (SCD) independently increased dementia incidence with adjusted hazard ratio of 1.286, 1.697, and 1.748 respectively
Subjects having both SCD and depression had a higher risk of dementia than having depression or SCD alone

Summary

Introduction

Dementia is a neurodegenerative disorder characterized by progressive cognitive impairment, behavioral disturbances, and a loss of daily function [1]. Pharmacological treatments have been largely ineffective in modifying the disease; focus has shifted to the prevention of dementia by identifying modifiable risk factors in individuals at increased risk of developing the disease [3,4,5,6,7]. Late-life depression is an important risk factor for dementia [8]. Depressive illness has been shown to play an important role in the development of dementia [11,12]. A previous metaanalysis found that a history of depression increased the risk of dementia twofold [13]. Population-based cohort studies have repeatedly shown that depression is an independent risk factor for vascular dementia (VD) and Alzheimer’s disease (AD) [14,15,16]

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Conclusion