Depression Plays a Moderating Role in the Cognitive Decline Associated With Changes of Brain White Matter Hyperintensities.

Objective: In the elderly, depression and white matter hyperintensities (WMH) are common and associated with cognitive impairment. This study investigated the possible interactions between depression and WMH in their influences on cognition of the elderly.

Methods: Using multiple neuropsychological tests, we evaluated the cognitive function of 122 community-dwelling elders with depression at baseline between November 2008 and February 2009.

Synergistic interaction between APOE and family history of Alzheimer's disease on cerebral amyloid deposition and glucose metabolism.

Background: Recently, the field of gene-gene or gene-environment interaction research appears to have gained growing interest, although it is seldom investigated in Alzheimer's disease (AD). Hence, the current study aims to investigate interaction effects of the key genetic and environmental risks-the apolipoprotein ε4 allele (APOE4) and family history of late-onset AD (FH)-on AD-related brain changes in cognitively normal (CN) middle-aged and older adults.

Methods: [C] Pittsburg compound-B (PiB) positron emission tomography (PET) imaging as well as [F] fluoro-2-deoxyglucose (FDG) PET that were simultaneously taken with T1-weighted magnetic resonance imaging (MRI) were obtained from 268 CNs from the Korean Brain Aging Study for Early Diagnosis and Prediction of AD (KBASE).

Overview of the Korean Longitudinal Study on Cognitive Aging and Dementia.

Objective: Due to an unprecedented rate of population aging, South Korea is facing a dementia epidemic. For this reason, the Korean Longitudinal Study on Cognitive Aging and Dementia (KLOSCAD) was launched in 2009 with support from the Korean Health Industry Development Institute to investigate the epidemiology, biopsychosocial risk factors, and outcomes of dementia and dementia-related conditions.

Methods: The KLOSCAD is the first nationwide multi-center population-based prospective cohort study.

Differential effects of completed and incomplete pregnancies on the risk of Alzheimer disease.

Objective: To investigate the effects of completed pregnancy with childbirth and incomplete pregnancy without childbirth on the late-life cognition and the risk of Alzheimer disease (AD) in women.

Methods: Using the pooled data of 3,549 women provided by 2 population-based cohort studies, we conducted logistic regression analyses to examine retrospectively the associations of completed and incomplete pregnancy with the risks of mild cognitive impairment and AD. For women without dementia, we also conducted analyses of covariance to examine the associations of completed and incomplete pregnancy with Mini-Mental State Examination (MMSE) score.

Prevalence and Risk Factors of Abusive Behaviors in the Caregivers of People with Dementia in Korea.

Objective: We investigated the prevalence and risk factors of physically abusive behaviors (PhAB) and psychologically abusive behaviors (PsAB) towards people with dementia (PWD) in family caregivers, and compared their prevalences between East Asian and Western countries.

Methods: We estimated the prevalence and risk factors of PhAB and PsAB in 467 Korean pairs of community-dwelling PWD and their primary family caregivers. We evaluated abusive behaviors using the Modified Conflict Tactics Scale.

Impact of Mild Cognitive Impairment on Mortality and Cause of Death in the Elderly.

Background: Mild cognitive impairment (MCI) is a cognitive state that lies on the continuum between normal aging and dementia, and the prevalence of MCI is higher than dementia. However, the risk for mortality of people with MCI has been far less studied than that of people with dementia, and the population attributable risk percent (PAR%) of death attributable to MCI has not been estimated yet.

Objective: To investigate the impact of MCI on mortality and the cause of death in the elderly, and to estimate the PAR% of deaths attributable to MCI.

Effects of lifetime cumulative ginseng intake on cognitive function in late life.

Background: We investigated the effects of lifetime cumulative ginseng intake on cognitive function in a community-dwelling population-based prospective cohort of Korean elders.

Methods: Community-dwelling elders (N = 6422; mean age = 70.2 ± 6.

Sleep and cognitive decline: A prospective nondemented elderly cohort study.

Objective: To investigate sleep disturbances that induce cognitive changes over 4 years in nondemented elderlies.

Methods: Data were acquired from a nationwide, population-based, prospective cohort of Korean elderlies (2,238 normal cognition [NC] and 655 mild cognitive impairment [MCI]). At baseline and 4-year follow-up assessments, sleep-related parameters (midsleep time, sleep duration, sleep latency, subjective sleep quality, sleep efficiency, and daytime dysfunction) and cognitive status were measured using the Pittsburgh Sleep Quality Index and Consortium to Establish a Registry for Alzheimer's Disease Assessment, respectively.

Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease: Methodology and Baseline Sample Characteristics.

Objective: The Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's disease (KBASE) aimed to recruit 650 individuals, aged from 20 to 90 years, to search for new biomarkers of Alzheimer's disease (AD) and to investigate how multi-faceted lifetime experiences and bodily changes contribute to the brain changes or brain pathologies related to the AD process.

Methods: All participants received comprehensive clinical and neuropsychological evaluations, multi-modal brain imaging, including magnetic resonance imaging, magnetic resonance angiography, [C]Pittsburgh compound B-positron emission tomography (PET), and [F]fluorodeoxyglucose-PET, blood and genetic marker analyses at baseline, and a subset of participants underwent actigraph monitoring and completed a sleep diary. Participants are to be followed annually with clinical and neuropsychological assessments, and biannually with the full KBASE assessment, including neuroimaging and laboratory tests.

Differential effects of blood insulin and HbA1c on cerebral amyloid burden and neurodegeneration in nondiabetic cognitively normal older adults.

We tested the hypothesis that lower insulin or higher glycated hemoglobin (HbA1c) levels in blood are associated with increased cerebral beta amyloid (Aβ) deposition and neurodegeneration in nondiabetic cognitively normal (CN) older adults. A total of 205 nondiabetic CN older adults underwent comprehensive clinical assessment, [C]Pittsburgh compound B (PiB)-positron emission tomography (PET), [F]fluorodeoxyglucose-PET, magnetic resonance imaging, and blood sampling for fasting insulin and HbA1c measurement. Lower blood insulin was significantly associated with increased Aβ positivity rates and decreased cerebral glucose metabolism in the AD-signature region.

Sex-specific association of sex hormones and gonadotropins, with brain amyloid and hippocampal neurodegeneration.

This study aimed to examine the sex-specific association between serum sex hormones and gonadotropins and the cerebral beta-amyloid (Aβ) burden and hippocampal neurodegeneration in subjects with normal cognition and impaired cognition. Two hundred sixty-five older subjects received clinical assessments, serum measurements of sex hormones, gonadotropins, C-Pittsburgh compound B-positron emission tomography, and magnetic resonance imaging. In females, higher free testosterone and gonadotropin levels were associated with lower cerebral Aβ positivity.

Multimodal Cognitive Enhancement Therapy for Patients with Mild Cognitive Impairment and Mild Dementia: A Multi- Center, Randomized, Controlled, Double-Blind, Crossover Trial.

We developed and evaluated the effect of Multimodal Cognitive Enhancement Therapy (MCET) consisting of cognitive training, cognitive stimulations, reality orientation, physical therapy, reminiscence therapy, and music therapy in combination in older people with mild cognitive impairment (MCI) or mild dementia. This study was a multi-center, double-blind, randomized, placebo-controlled, two-period cross-over study (two 8-week treatment phases separated by a 4-week wash-out period). Sixty-four participants with MCI or dementia whose Clinical Dementia Rating was 0.

Association of Cerebral Amyloidosis, Blood Pressure, and Neuronal Injury with Late-Life Onset Depression.

Previous literature suggests that Alzheimer's disease (AD) process may contribute to late-life onset depression (LLOD). Therefore, we investigated the association of LLOD with cerebral amyloidosis and neuronal injury, the two key brain changes in AD, along with vascular risks. Twenty nine non-demented individuals who first experienced major depressive disorder (MDD) after age of 60 years were included as LLOD subjects, and 27 non-demented elderly individuals without lifetime experience of MDD were included as normal controls (NC).

How Different are Quality of Life Ratings for People with Dementia Reported by Their Family Caregivers from Those Reported by the Patients Themselves?

Background: Measurements of patient quality of life (QoL) play a major role in the management of dementia.

Objective: We investigated the self-proxy discrepancy of QoL ratings in the elderly and the impact of dementia severity on the discrepancy.

Methods: QoL of 718 patients with dementia and 651 non-demented elderly were rated by themselves and their caregivers (CG) using the Quality of Life-Alzheimer's Disease (QoL-AD).

Differences in knowledge of dementia among older adults with normal cognition, mild cognitive impairment, and dementia: A representative nationwide sample of Korean elders.

Objective: Lack of knowledge about a disease could impede early diagnosis and may lead to delays in seeking appropriate medical care. The aim of this study was to explore knowledge of dementia (KOD) and to find the determinants of KOD among three groups: older adults with normal cognition, mild cognitive impairment (MCI), and dementia.

Methods: A representative nationwide sample of 6141 Korean elders aged 65 years or older participated in face-to-face interviews and answered 14 questions pertaining to general information, etiology, symptoms, and treatment of dementia.

The Effect of Choline Acetyltransferase Genotype on Donepezil Treatment Response in Patients with Alzheimer's Disease.

Objective: We examined the difference in responses to donepezil between carriers and non-carriers of the A allele at the +4 position of the choline acetyltransferase (ChAT) gene in Koreans.

Methods: Patients who met the criteria for probable Alzheimer's disease (AD) (n=199) were recruited. Among these, 145 completed the 12-week follow-up evaluation and 135 completed the 26-week scheduled course.

Epidemiology of MRI-defined vascular depression: A longitudinal, community-based study in Korean elders.

Background: There are no cross-sectional or longitudinal epidemiological studies present on MRI-defined vascular depression in community populations. The purpose of this study was to estimate the prevalence rates of both vascular and non-vascular late life depression (LLD) at baseline, to examine the natural course of LLD, and to investigate the influence of White matter hyperintensities (WMHs) on depression after three years.

Method: The baseline study employed a two-stage design, Phase I population survey (n=783) and Phase II diagnostic evaluation (n=122).

A normative study of the disability assessment for dementia in community-dwelling elderly koreans.

Objective: We investigated demographic influences on Korean version of Disability Assessment for Dementia (DAD-K) performance and developed normative data for DAD-K.

Methods: The DAD-K was administered to 2362 normal controls (NCs), 296 patients with mild cognitive impairment (MCI) and 293 patients with Alzheimer's disease (AD). MANOVA and ROC curve analysis were used to compare DAD-K performance and the diagnostic accuracy of DAD-K, respectively.

Effects of social supports on burden in caregivers of people with dementia.

Background: Social support programs for dementia caregivers were widely used in order to reduce care burden. We investigated which types of social supports can reduce psychological and non-psychological burdens of dementia caregivers, and explored the mechanism of those social supports.

Methods: We evaluated 731 community-dwelling dementia patients and their caregivers from the National Survey of Dementia Care in South Korea.

Improvement of Screening Accuracy of Mini-Mental State Examination for Mild Cognitive Impairment and Non-Alzheimer's Disease Dementia by Supplementation of Verbal Fluency Performance.

Objective: THIS STUDY AIMED TO INVESTIGATE WHETHER THE SUPPLEMENTATION OF VERBAL FLUENCY: Animal category test (VF) performance can improve the screening ability of Mini-Mental State Examination (MMSE) for mild cognitive impairment (MCI), dementia and their major subtypes.

Methods: Six hundred fifty-five cognitively normal (CN), 366 MCI [282 amnestic MCI (aMCI); 84 non-amnestic MCI (naMCI)] and 494 dementia [346 Alzheimer's disease (AD); and 148 non-Alzheimer's disease dementia (NAD)] individuals living in the community were included (all aged 50 years and older) in the study.

Results: The VF-supplemented MMSE (MMSE+VF) score had a significantly better screening ability for MCI, dementia and overall cognitive impairment (MCI plus dementia) than the MMSE raw score alone.

Development of a screening algorithm for Alzheimer's disease using categorical verbal fluency.

We developed a weighted composite score of the categorical verbal fluency test (CVFT) that can more easily and widely screen Alzheimer's disease (AD) than the mini-mental status examination (MMSE). We administered the CVFT using animal category and MMSE to 423 community-dwelling mild probable AD patients and their age- and gender-matched cognitively normal controls. To enhance the diagnostic accuracy for AD of the CVFT, we obtained a weighted composite score from subindex scores of the CVFT using a logistic regression model: logit (case)  = 1.

Prevalence of neuropsychiatric syndromes in Alzheimer's disease (AD).

This study aimed to estimate the prevalence and explore the multidimensional complexity of the neuropsychiatric syndromes of AD. Neuropsychiatric symptoms and syndromes of 216 subjects with probable and possible AD diagnosed by NINCDS-ADRDA criteria were evaluated by the Korean version of behavior rating scale for dementia (BRSD-K). The prevalence rate of six neuropsychiatric syndromes (depressive symptoms, inertia, vegetative symptoms, irritability/aggression, behavioral dysregulation, psychotic symptoms) and comorbid neuropsychiatric syndromes were calculated according to the Clinical Dementia Rating scale.

Development of the Subjective Memory Complaints Questionnaire.

Aim: We aimed to evaluate the psychometric properties of the Subjective Memory Complaints Questionnaire (SMCQ).

Methods: The reliability of the SMCQ was evaluated by testing its internal consistency and test-retest reliability. Pearson correlation analyses were performed to assess the concurrent validity.

Development of a Korean version of the behavior rating scale for dementia (BRSD-K).

Objective: The purpose of this study was to develop a Korean version of the behavior rating scale for dementia (BRSD-K) for evaluating behavioral and psychological symptoms of dementia.

Methods: The BRSD-K was administered to the informants of 268 subjects with dementia. Internal, inter-rater and test-retest reliabilities were tested.

Topographic patterns of brain functional impairment progression according to clinical severity staging in 116 Alzheimer disease patients: FDG-PET study.

The study aimed to explore topographic progression pattern of brain functional impairment according to clinical stage in Alzheimer disease (AD). One hundred and sixteen AD patients and 25 normal subjects underwent a [18F] fluorodeoxyglucose-positron emission tomography scan. Regional cerebral glucose metabolism was compared between severity groups based on the Clinical Dementia Rating through voxel-based analyses.