Association of Depression With the Progression of Multimorbidity in Older Adults: A Population-Based Cohort Study.

BACKGROUND: The relationship between depression and the risk of multimorbidity progression has rarely been studied in older adults. This study was aimed to determine whether depression is associated with progression in the severity and complexity of multimorbidity, considering the influence of depression's severity and subtype. METHODS: As a part of the Korean Longitudinal Study on Cognitive Aging and Dementia, this population-based cohort study followed a random sample of community-dwelling Koreans aged 60 and older for 8 years at 2-year intervals starting in 2010. Participants included those who completed mood and multimorbidity assessments and did not exhibit complex multimorbidity at the study's outset. Depression was assessed using the Geriatric Depression Scale, while multimorbidity was evaluated using the Cumulative Illness Rating Scale. The study quantified multimorbidity complexity by counting affected body systems and measured multimorbidity severity by averaging scores across 14 body systems. FINDINGS: The 2,486 participants (age = 69.1 ± 6.5 years, 57.6% women) were followed for 5.9 ± 2.4 years. Linear mixed models revealed that participants with depression had a faster increase in multimorbidity complexity score (ß = .065, SE = 0.019, p = 0.001) than those without depression, but a comparable increase in multimorbidity severity score (ß = .001, SE = .009, p = 0.870) to those without depression. Cox proportional hazard models revealed that depression was associated with the risk of developing highly complex multimorbidity affecting five or more body systems, particularly in severe or anhedonic depression. INTERPRETATION: Depression was associated with the worsening of multimorbidity in Korean older adults, particularly when severe or anhedonic. Early screening and management of depression may help to reduce the burden of multimorbidity in older adults.

What is the impact of one's chronic illness on his or her spouse's future chronic illness: a community-based prospective cohort study.

BACKGROUND: Integrating a joint approach to chronic disease management within the context of a couple has immense potential as a valuable strategy for both prevention and treatment. Although spousal concordance has been reported in specific chronic illnesses, the impact they cumulatively exert on a spouse in a longitudinal setting has not been investigated. We aimed to determine whether one's cumulative illness burden has a longitudinal impact on that of their spouse. METHODS: Data was acquired from a community-based prospective cohort that included Koreans aged 60 years and over, randomly sampled from 13 districts nationwide. Data from the baseline assessment (conducted from November 2010 to October 2012) up to the 8-year follow-up assessment was analyzed from October 2021 to November 2022. At the last assessment, partners of the index participants were invited, and we included 814 couples in the analysis after excluding 51 with incomplete variables. Chronic illness burden of the participants was measured by the Cumulative Illness Rating Scale (CIRS). Multivariable linear regression and causal mediation analysis were used to examine the longitudinal effects of index chronic illness burden at baseline and its change during follow-up on future index and spouse CIRS scores. RESULTS: Index participants were divided based on baseline CIRS scores (CIRS < 6 points, n = 555, mean [SD] age 66.3 [4.79] years, 43% women; CIRS ≥ 6 points, n = 259, mean [SD] age 67.7 [4.76] years, 36% women). The baseline index CIRS scores and change in index CIRS scores during follow-up were associated with the spouse CIRS scores (ß = 0.154 [SE: 0.039], p < 0.001 for baseline index CIRS; ß = 0.126 [SE: 0.041], p = 0.002 for change in index CIRS) at the 8-year follow-up assessment. Subgroup analysis found similar results only in the high CIRS group. The baseline index CIRS scores and change in index CIRS scores during follow-up had both direct and indirect effects on the spouse CIRS scores at the 8-year follow-up assessment. CONCLUSIONS: The severity and course of one's chronic illnesses had a significant effect on their spouse's future chronic illness particularly when it was severe. Management strategies for chronic diseases that are centered on couples may be more effective.

The impact of the COVID-19 pandemic on depression in community-dwelling older adults: a prospective cohort study.

BACKGROUND: There are growing concerns about the impact of the COVID-19 pandemic on the mental health of older adults. We examined the effect of the pandemic on the risk of depression in older adults. METHODS: We analyzed data from the prospective cohort study of Korean older adults, which has been followed every 2 years. Among the 2308 participants who completed both the third and the fourth follow-up assessments, 58.4% completed their fourth follow-up before the outbreak of COVID-19 and the rest completed it during the pandemic. We conducted face-to-face diagnostic interviews using Mini International Neuropsychiatric Interview and used Geriatric Depression Scale. We performed generalized estimating equations and logistic regression analyses. RESULTS: The COVID-19 pandemic was associated with increased depressive symptoms in older adults [b (standard error) = 0.42 (0.20), p = 0.040] and a doubling of the risk for incident depressive disorder even in euthymic older adults without a history of depression (odds ratio = 2.44, 95% confidence interval 1.18-5.02, p = 0.016). Less social activities, which was associated with the risk of depressive disorder before the pandemic, was not associated with the risk of depressive disorder during the pandemic. However, less family gatherings, which was not associated with the risk of depressive disorder before the pandemic, was associated with the doubled risk of depressive disorder during the pandemic. CONCLUSIONS: The COVID-19 pandemic significantly influences the risk of late-life depression in the community. Older adults with a lack of family gatherings may be particularly vulnerable.

Evidence of risky driving in Korean older adults: A longitudinal cohort.

OBJECTIVES: The aim of this study was to determine the differences in the risk factors for dangerous driving between older adults with normal cognition and those with cognitive impairment. DESIGN: The driving risk questionnaire (DRQ) that was applied to a community-dwelling older adult cohort and 2 years of accident/violation records from the National Police Agency were analyzed. We conducted regression analyses with the presence or absence of risky driving based on records (accidents + violations) 2 years before and after evaluation as a dependent variable and dichotomized scores of each risky driving factor as independent variables. RESULTS: According to four identified factors-crash history, safety concern, reduced mileage, and aggressive driving-significant associations were found between risky driving over the past 2 years and crash history and for aggressive driving in the normal cognition group. In the cognitive impairment group, only crash history was significantly associated, although safety concerns showed a trend toward significance. CONCLUSIONS: In this study, it was suggested that the factors of DRQ have a significant association with actual risky driving. Our results are expected to contribute to establishing the evidence for evaluating and predicting risky driving and advising whether to continue driving in clinics.

Parental history of dementia and the risk of dementia: A cross-sectional analysis of a global collaborative study.

BACKGROUND: Parental history of dementia appears to increase the risk of dementia, but there have been inconsistent results. We aimed to investigate whether the association between parental history of dementia and the risk of dementia are different by dementia subtypes and sex of parent and offspring. METHODS: For this cross-sectional study, we harmonized and pooled data for 17,194 older adults from nine population-based cohorts of eight countries. These studies conducted face-to-face diagnostic interviews, physical and neurological examinations, and neuropsychological assessments to diagnose dementia. We investigated the associations of maternal and paternal history of dementia with the risk of dementia and its subtypes in offspring. RESULTS: The mean age of the participants was 72.8 ± 7.9 years and 59.2% were female. Parental history of dementia was associated with higher risk of dementia (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.15-1.86) and Alzheimer's disease (AD) (OR = 1.72, 95% CI = 1.31-2.26), but not with the risk of non-AD. This was largely driven by maternal history of dementia, which was associated with the risk of dementia (OR = 1.51, 95% CI = 1.15-1.97) and AD (OR = 1.80, 95% CI = 1.33-2.43) whereas paternal history of dementia was not. These results remained significant when males and females were analyzed separately (OR = 2.14, 95% CI = 1.28-3.55 in males; OR = 1.68, 95% CI = 1.16-2.44 for females). CONCLUSIONS: Maternal history of dementia was associated with the risk of dementia and AD in both males and females. Maternal history of dementia may be a useful marker for identifying individuals at higher risk of AD and stratifying the risk for AD in clinical trials.

Mood disorders increase mortality mainly through dementia: A community-based prospective cohort study.

OBJECTIVE: The effects of mood disorders on mortality may be mediated by their effects on the risk of dementia, and interventions to reduce the occurrence of dementia may reduce their overall mortality. This study aimed to investigate the direct effects of depressive and bipolar disorders on the 6-year risk of mortality and also their indirect effects on mortality due to their effect on the risk of dementia. METHODS: A total of 5101 Koreans were selected from a community-based prospective cohort study, and 6-year risks of mortality and dementia in participants with depressive and bipolar disorders were estimated by Cox proportional hazard analysis. The direct and indirect effects of depressive and bipolar disorders on the risk of mortality were estimated using structural equation modeling. RESULTS: The depressive and bipolar disorder groups showed 51% and 85% higher 6-year mortality, and 82% and 127% higher risk of dementia, respectively, compared to euthymic controls. The effects of depressive and bipolar disorders on mortality were mainly mediated by their effects on the risk of dementia in a structural equation model. The direct effects of each mood disorder on mortality were not significant. CONCLUSION: Both depressive and bipolar disorders increased the risks of mortality and dementia, and the effects of mood disorders on mortality were mainly mediated through dementia. As dementia occurs later in life than mood disorders, measures to prevent it may effectively reduce mortality in individuals with a history of mood disorders, as well as being more feasible than attempting to control other causes of death.

Efficacy of Internet-Based Acceptance and Commitment Therapy for Depressive Symptoms, Anxiety, Stress, Psychological Distress, and Quality of Life: Systematic Review and Meta-analysis.

BACKGROUND: Acceptance and commitment therapy (ACT) is an empirically supported transdiagnostic approach that involves mindfulness processes and behavior change processes for valued living. OBJECTIVE: This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed to assess the efficacy of internet-based ACT (iACT) for depressive symptoms, anxiety, stress, psychological distress, and quality of life (QoL). METHODS: PubMed, CINAHL, PsycINFO, and SCOPUS databases were searched to identify relevant RCTs published up to June 5, 2021. The included RCTs were assessed using the Cochrane Collaboration risk-of-bias tool. The use of either a random effects model or fixed effects model was determined using I2 statistic values for heterogeneity. Subgroup analyses were conducted according to the type of control group, the use of therapist guidance, delivery modes, and the use of targeted participants, when applicable. RESULTS: A total of 39 RCTs met the inclusion criteria. Meta-analyses found small effects of iACT on depressive symptoms, anxiety, stress, psychological distress, and QoL at the immediate posttest and follow-up. There was no significant effect of iACT on stress at follow-up. Subgroup analyses showed small to medium effects of iACT on all the outcomes at the immediate posttest and follow-up compared with the passive control groups. In contrast, subgroup analyses that compared iACT with active control groups found no differences between groups on stress, psychological distress, and QoL at the immediate posttest or on depressive symptoms, anxiety, and stress at follow-up. In addition, subgroup analyses conducted according to the use of therapist guidance, delivery modes, and the use of targeted participants found no statistically significant subgroup differences among studies in all the outcomes, except for the subgroup difference among studies according to the use of targeted participants for depressive symptoms at the immediate posttest (ie, a statistically significant, larger effect of iACT when studies targeted people with depressive symptoms). The overall risk of bias across the studies was unclear. CONCLUSIONS: The findings of this study contribute to the body of evidence regarding the effects of iACT on depressive symptoms, anxiety, stress, psychological distress, and QoL and may be applicable in any population, as ACT is a transdiagnostic approach. Few studies have compared iACT with active control conditions, especially for stress and psychological distress at the immediate posttest and follow-up. In addition, the active control conditions varied among the included studies. Further high-quality studies are needed to better understand whether iACT is comparable or superior to other evidence-based interventions, such as cognitive behavioral therapy, in decreasing depressive symptoms, anxiety, stress, and psychological distress and improving QoL.

The Effects of Internet-Based Acceptance and Commitment Therapy on Process Measures: Systematic Review and Meta-analysis.

BACKGROUND: Acceptance and commitment therapy (ACT) is based on a psychological flexibility model that encompasses 6 processes: acceptance, cognitive defusion, self-as-context, being present, values, and committed action. OBJECTIVE: This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed to examine the effects of internet-based ACT (iACT) on process measures. METHODS: A comprehensive search was conducted using 4 databases. The quality of the included RCTs was assessed using the Cochrane Collaboration Risk of Bias Tool. A random-effects or fixed-effects model was used. Subgroup analyses for each outcome were conducted according to the type of control group, use of therapist guidance, delivery modes, and use of targeted participants, when applicable. RESULTS: A total of 34 RCTs met the inclusion criteria. This meta-analysis found that iACT had a medium effect on psychological flexibility and small effects on mindfulness, valued living, and cognitive defusion at the immediate posttest. In addition, iACT had a small effect on psychological flexibility at follow-up. The overall risk of bias across studies was unclear. CONCLUSIONS: Relatively few studies have compared the effects of iACT with active control groups and measured the effects on mindfulness, valued living, and cognitive defusion. These findings support the processes of change in iACT, which mental health practitioners can use to support the use of iACT.

Swallowing Outcomes Following Voice Therapy in Multiple System Atrophy with Dysphagia: Comparison of Treatment Efficacy with Parkinson's Disease.

Difficulties with speech and swallowing occur in patients with Parkinsonism. Lee Silverman Voice Treatment (LSVT) is proven as an effective treatment for speech and swallowing function in idiopathic Parkinson's disease (IPD). The effect of LSVT on swallowing function in multiple system atrophy-cerebellar type (MSA-C) is unknown. We sought to determine LSVT's effect on swallowing function in MSA-C patients compared to IPD patients. LSVT-LOUD was performed on 13 patients with Parkinsonism (6 IPD and 7 MSA-C). Maximum phonation time (MPT), voice intensity, Speech Handicap Index-15 (SHI-15), Swallowing-Quality of Life (SWAL-QOL), National Institutes of Health-swallowing safety scale (NIH-SSS), and videofluoroscopic dysphagia scale (VDS) before and after LSVT were analyzed and reevaluated three months after treatment. The IPD and MSA-C groups showed significant improvements in overall speech and swallowing measures after LSVT. In particular, pharyngeal phase score and total score of VDS improved significantly in both groups. A two-way repeated-measure ANOVA revealed a significant main effect for time in the MPT, voice intensity, NIH-SSS, pharyngeal phase score and total score of VDS, psychosocial subdomain of SHI-15, and SWAL-QOL. The MSA-C group experienced less overall improvement in swallowing function, but the two groups had an analogous pattern of improvement. In conclusion, LSVT is effective for enhancing swallowing function, particularly in the pharyngeal phase, in both IPD and MSA-C patients. This study demonstrated that LSVT elicits significant improvements in MSA-C patients. We deemed LSVT to be an effective treatment for IPD and MSA-C patients who suffer from dysphagia.

A Quasi-experimental Study Measuring the Effectiveness of Two Empathy Enhancement Programs on Caregivers Working with Older Adults Living Alone.

Objectives: This quasi-experimental study assessed the effectiveness of two empathy enhancement programs on direct care workers of older adults living alone in South Korea.Methods: A total of 104 direct care workers participated in either a simulation-based program or a lecture-based program. Data were collected prior to and 2 weeks after the program implementation using self-reported questionnaires.Results: The lecture-based group had significantly higher levels of empathy compared to the simulation-based group. Pretest-posttest differences were found in the lecture-based group only, including higher levels of empathy and caring efficacy and lower levels of secondary traumatic stress and burnout.Conclusions: More studies are needed to identify helpful components of empathy enhancement programs to direct care workers working with older adults living alone. Also, a further randomized controlled trial study is needed to assess programs' effectiveness on older adults living alone and direct care workers.Clinical implications: A lecture-based empathy enhancement program can increase levels of empathy and caring efficacy of direct care workers working with older adults and decrease care workers' levels of burnout and stress. Training for direct care workers of older adults is needed to improve the empathy of direct care workers while reducing their stress and burnout.

Executive dysfunction and risk of suicide in older adults: a population-based prospective cohort study.

OBJECTIVE: It is uncertain what factors increases the risk of suicide in older adults without depression, and it is unknown whether executive dysfunction (ED) is one of those factors. We aimed to examine the effect of ED on the risk of suicide in non-demented older adults without depression. METHODS: In an ongoing population-based prospective cohort of Korean older adults, we identified suicide using the National Mortality Database and suicidal ideation or attempt (SIA) based on the Korean version of the Mini International Neuropsychiatric Interview. We defined ED as performing below -1.5 SD of age-adjusted, gender-adjusted and education-adjusted norms in any of following tests: Frontal Assessment Battery, Trail Making Test A, Digit Span Test or Verbal Fluency Test. RESULTS: The mean age of the 4791 participants at baseline was 69.7 (SD 6.4) years, and 57.1% of them were women (mean follow-up duration=4.9 years). ED at baseline increased the risk of suicide by about seven times (HR 7.20, 95% CI 1.84 to 28.12, p=0.005) but did not change the risk of SIA. However, cognitive impairment without ED did not change the risks of suicide and SIA. In participants with ED, being aged 75 years or above, living alone, and having a low socioeconomic status were associated with the risk of suicide. CONCLUSION: ED is a strong risk factor of late life suicide independent from depression, particularly in very old adults living in disadvantaged environments.

Chronic subsyndromal depression and risk of dementia in older adults.

OBJECTIVES: Subsyndromal depression is prevalent and associated with poor outcomes in late life, but its effect on the risk of dementia has barely been investigated. This study is aimed to investigate the effect of subsyndromal depression on dementia risk in cognitively normal older adults and patients with mild cognitive impairment. METHODS: Data were collected from a nationwide, population-based, prospective cohort study on a randomly sampled Korean elderly population aged 60 years or older, which has been followed every 2 years. Using 6-year follow-up data of 4456 non-demented elderly, the authors examined the risk of dementia associated with late-onset subsyndromal depression using multivariate Cox proportional hazard models. After standardized diagnostic interviews, subsyndromal depression and dementia were diagnosed by the operational diagnostic criteria and Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria, respectively. RESULTS: Subsyndromal depression tripled the risk of dementia in non-demented elderly individuals (hazard ratio = 3.02, 95% confidence interval = [1.56, 5.85], p < 0.001). In subgroup analyses, subsyndromal depression was associated with the risk of dementia in cognitively normal participants only (hazard ratio = 4.59, 95% confidence interval = [1.20, 17.54], p = 0.026); chronic/recurrent subsyndromal depression with increasing severity during the follow-up period was associated with the risk of dementia (hazard ratio = 15.34, 95% confidence interval = [4.19, 56.18], p < 0.001). CONCLUSION: Late-onset subsyndromal depression is a potential predictor of incident dementia when it is chronic or recurrent with increasing severity in cognitively normal older adults.

A factorial randomized controlled trial to examine separate and combined effects of a simulation-based empathy enhancement program and a lecture-based education program on family caregivers of people with dementia.

OBJECTIVES: The present study was a 2 × 2 factorial randomized controlled trial that examined if a simulation-based empathy enhancement program and a lecture-based education program, together or separately, improved outcomes of family caregivers of people with dementia. METHOD: A total of 101 participants were randomly assigned to simulation-based education only, lecture-based education only, simulation-based education plus lecture-based education, or treatment as usual. Data were analyzed using a two-way analysis of covariance while controlling for pretest results, kinship, and gender. RESULTS: Statistically significant interaction effects between the simulation program and the lecture program were found in the levels of well-being and helplessness. The lecture program accompanied by the simulation program led to higher level of well-being in terms of happiness and lower level of helplessness than the lecture program alone. Caregivers with the lecture program provided led to less frequent use of dysfunctional coping strategies than those with no lecture program provided. Caregivers with the simulation program provided led to more frequent use of emotion-focused coping strategies than those with no simulation program provided. CONCLUSIONS: Findings of the present study support benefits of combined of and separate simulation-based and lecture-based programs on family caregivers of people with dementia in important outcomes affecting quality of care and quality of lives in families of people with dementia. Further studies are needed to identify intervention components that can improve empathy of family caregivers of people with dementia and be embedded into a multicomponent program tailored better to families in different needs.

Does parity matter in women's risk of dementia? A COSMIC collaboration cohort study.

BACKGROUND: Dementia shows sex difference in its epidemiology. Childbirth, a distinctive experience of women, is associated with the risk for various diseases. However, its association with the risk of dementia in women has rarely been studied. METHODS: We harmonized and pooled baseline data from 11 population-based cohorts from 11 countries over 3 continents, including 14,792 women aged 60 years or older. We investigated the association between parity and the risk of dementia using logistic regression models that adjusted for age, educational level, hypertension, diabetes mellitus, and cohort, with additional analyses by region and dementia subtype. RESULTS: Across all cohorts, grand multiparous (5 or more childbirths) women had a 47% greater risk of dementia than primiparous (1 childbirth) women (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.10-1.94), while nulliparous (no childbirth) women and women with 2 to 4 childbirths showed a comparable dementia risk to primiparous women. However, there were differences associated with region and dementia subtype. Compared to women with 1 to 4 childbirths, grand multiparous women showed a higher risk of dementia in Europe (OR = 2.99, 95% CI = 1.38-6.47) and Latin America (OR = 1.49, 95% CI = 1.04-2.12), while nulliparous women showed a higher dementia risk in Asia (OR = 2.15, 95% CI = 1.33-3.47). Grand multiparity was associated with 6.9-fold higher risk of vascular dementia in Europe (OR = 6.86, 95% CI = 1.81-26.08), whereas nulliparity was associated with a higher risk of Alzheimer disease (OR = 1.91, 95% CI 1.07-3.39) and non-Alzheimer non-vascular dementia (OR = 3.47, 95% CI = 1.44-8.35) in Asia. CONCLUSION: Parity is associated with women's risk of dementia, though this is not uniform across regions and dementia subtypes.

Epidemiological characteristics of subsyndromal depression in late life.

OBJECTIVES: Subsyndromal depression is prevalent and associated with poor outcomes in late life, but its epidemiological characteristics have barely been investigated. The aim of this prospective cohort study is to compare the prevalence, incidence and risk factors of subsyndromal depression with those of syndromal depression including major and minor depressive disorders in community-dwelling elderly individuals. METHODS: In a nationwide community-based study of randomly sampled Korean elderly population aged 60 years or older (N = 6640), depression was assessed with standardized diagnostic interviews. At baseline and at 2-year and 4-year follow-ups, the authors diagnosed subsyndromal depression by the operational criteria and syndromal depression by the Diagnostic and Statistical Manual of Mental Disorders (4th ed.) diagnostic criteria. Multivariate logistic regression analyses were conducted to identify the risk factors for incident depression. RESULTS: The age- and gender-adjusted prevalence rate of subsyndromal depression was 9.24% (95% confidence interval = [8.54, 9.93]), which was 2.4-fold higher than that of syndromal depression. The incidence rate of subsyndromal depression was 21.70 per 1000 person-years (95% confidence interval = [19.29, 24.12]), which was fivefold higher than that of syndromal depression. The prevalence to incidence ratio of subsyndromal depression was about half that of syndromal depression. The risk for subsyndromal depression was associated with female gender, low socioeconomic status, poor social support and poor sleep quality, while that of syndromal depression was associated with old age and less exercise. CONCLUSION: Subsyndromal depression should be validated as a clinical diagnostic entity, at least in late life, since it has epidemiological characteristics different from those of syndromal depression.

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. We used logistic regression models adjusted for covariates including age, sex, education, apolipoprotein E genotype, Geriatric Depression Scale, Cumulative Illness Rating Scale, and physical activity. RESULTS: In participants with NC, long sleep latency (>30 minutes), long sleep duration (≥7.95 hours), and late midsleep time (after 3:00 am) at baseline were related to the risk of cognitive decline at 4-year follow-up assessment; odds ratio (OR) was 1.40 for long sleep latency, 1.67 for long sleep duration, and 0.61 for late midsleep time. These relationships remained significant when these variables maintained their status throughout the follow-up period. Newly developed long sleep latency also doubled the risk of cognitive decline. In those with MCI, however, only long sleep latency reduced the chance of reversion to NC (OR = 0.69). INTERPRETATION: As early markers of cognitive decline, long sleep latency can be used for elderlies with NC or MCI, whereas long sleep duration and relatively early sleep time might be used for cognitively normal elderlies only. Ann Neurol 2018;83:472-482.

Gait Variability Can Predict the Risk of Cognitive Decline in Cognitively Normal Older People.

BACKGROUND: The aim of this study was to investigate the association of gait speed and gait variability, an index of how much gait parameters, such as step time, fluctuate step-to-step, with risk of cognitive decline in cognitively normal elderly individuals. While high gait variability is emerging as an early indicator of dementing illnesses, there is little research on whether high gait variability predicts cognitive decline in cognitively normal elderly who have no evidence of cognitive impairment. METHODS: In this 4-year prospective cohort study on 91 community-dwelling cognitively normal elderly individuals without cerebral ischemic burden or Parkinsonism, we evaluated gait speed and step time variability using a tri-axial accelerometer placed on the center of body mass, and diagnosed mild cognitive impairment (MCI) according to the International Working Group on MCI. We performed Kaplan-Meier analysis with consecutive log-rank testing for MCI-free survival by cohort-specific tertiles of gait speed; hazard ratios (HR) of incident MCI were estimated using Cox proportional hazards regression analysis adjusted for age, sex, education level, Cumulative Illness Rating Scale score, GDS score, and presence of the apolipoprotein E ε4 allele. RESULTS: Out of the 91 participants in the baseline assessment, 87 completed one or more 2-year follow-up assessments, and the median duration of follow-up was 47.1 months. Kaplan-Meier curves of incident MCI show evident differences in risk by gait variability group (χ2 = 9.64, p = 0.002, log-rank test). Mean MCI-free survival in the high variability group was 12% shorter than in the mid-to-low tertile group (47.4 ± 1.74 [SD] vs. 54.04 ± 0.52 months), while it was comparable between gait speed groups (51.59 ± 0.70 vs. 50.64 ± 1.77 months; χ2 = 1.16, p = 0.281). In multivariate analysis, subjects with high gait variability showed about 12-fold higher risk of MCI (HR = 11.97, 95% CI = 1.29-111.37) than those with mid-to-low variability. However, those with slow gait speed showed comparable MCI risk to those with mid-to-high speed (HR = 5.04, 95% CI = 0.53-48.18). CONCLUSIONS: Gait variability may be a better predictor of cognitive decline than gait speed in cognitively normal elderly individuals without cerebral ischemic burden or Parkinsonism.

Deep learning based low-cost high-accuracy diagnostic framework for dementia using comprehensive neuropsychological assessment profiles.

BACKGROUND: The conventional scores of the neuropsychological batteries are not fully optimized for diagnosing dementia despite their variety and abundance of information. To achieve low-cost high-accuracy diagnose performance for dementia using a neuropsychological battery, a novel framework is proposed using the response profiles of 2666 cognitively normal elderly individuals and 435 dementia patients who have participated in the Korean Longitudinal Study on Cognitive Aging and Dementia (KLOSCAD). METHODS: The key idea of the proposed framework is to propose a cost-effective and precise two-stage classification procedure that employed Mini Mental Status Examination (MMSE) as a screening test and the KLOSCAD Neuropsychological Assessment Battery as a diagnostic test using deep learning. In addition, an evaluation procedure of redundant variables is introduced to prevent performance degradation. A missing data imputation method is also presented to increase the robustness by recovering information loss. The proposed deep neural networks (DNNs) architecture for the classification is validated through rigorous evaluation in comparison with various classifiers. RESULTS: The k-nearest-neighbor imputation has been induced according to the proposed framework, and the proposed DNNs for two stage classification show the best accuracy compared to the other classifiers. Also, 49 redundant variables were removed, which improved diagnostic performance and suggested the potential of simplifying the assessment. Using this two-stage framework, we could get 8.06% higher diagnostic accuracy of dementia than MMSE alone and 64.13% less cost than KLOSCAD-N alone. CONCLUSION: The proposed framework could be applied to general dementia early detection programs to improve robustness, preciseness, and cost-effectiveness.

Age-related cognitive decline and associations with sex, education and apolipoprotein E genotype across ethnocultural groups and geographic regions: a collaborative cohort study.

BACKGROUND: The prevalence of dementia varies around the world, potentially contributed to by international differences in rates of age-related cognitive decline. Our primary goal was to investigate how rates of age-related decline in cognitive test performance varied among international cohort studies of cognitive aging. We also determined the extent to which sex, educational attainment, and apolipoprotein E ε4 allele (APOE*4) carrier status were associated with decline. METHODS AND FINDINGS: We harmonized longitudinal data for 14 cohorts from 12 countries (Australia, Brazil, France, Greece, Hong Kong, Italy, Japan, Singapore, Spain, South Korea, United Kingdom, United States), for a total of 42,170 individuals aged 54-105 y (42% male), including 3.3% with dementia at baseline. The studies began between 1989 and 2011, with all but three ongoing, and each had 2-16 assessment waves (median = 3) and a follow-up duration of 2-15 y. We analyzed standardized Mini-Mental State Examination (MMSE) and memory, processing speed, language, and executive functioning test scores using linear mixed models, adjusted for sex and education, and meta-analytic techniques. Performance on all cognitive measures declined with age, with the most rapid rate of change pooled across cohorts a moderate -0.26 standard deviations per decade (SD/decade) (95% confidence interval [CI] [-0.35, -0.16], p < 0.001) for processing speed. Rates of decline accelerated slightly with age, with executive functioning showing the largest additional rate of decline with every further decade of age (-0.07 SD/decade, 95% CI [-0.10, -0.03], p = 0.002). There was a considerable degree of heterogeneity in the associations across cohorts, including a slightly faster decline (p = 0.021) on the MMSE for Asians (-0.20 SD/decade, 95% CI [-0.28, -0.12], p < 0.001) than for whites (-0.09 SD/decade, 95% CI [-0.16, -0.02], p = 0.009). Males declined on the MMSE at a slightly slower rate than females (difference = 0.023 SD/decade, 95% CI [0.011, 0.035], p < 0.001), and every additional year of education was associated with a rate of decline slightly slower for the MMSE (0.004 SD/decade less, 95% CI [0.002, 0.006], p = 0.001), but slightly faster for language (-0.007 SD/decade more, 95% CI [-0.011, -0.003], p = 0.001). APOE*4 carriers declined slightly more rapidly than non-carriers on most cognitive measures, with processing speed showing the greatest difference (-0.08 SD/decade, 95% CI [-0.15, -0.01], p = 0.019). The same overall pattern of results was found when analyses were repeated with baseline dementia cases excluded. We used only one test to represent cognitive domains, and though a prototypical one, we nevertheless urge caution in generalizing the results to domains rather than viewing them as test-specific associations. This study lacked cohorts from Africa, India, and mainland China. CONCLUSIONS: Cognitive performance declined with age, and more rapidly with increasing age, across samples from diverse ethnocultural groups and geographical regions. Associations varied across cohorts, suggesting that different rates of cognitive decline might contribute to the global variation in dementia prevalence. However, the many similarities and consistent associations with education and APOE genotype indicate a need to explore how international differences in associations with other risk factors such as genetics, cardiovascular health, and lifestyle are involved. Future studies should attempt to use multiple tests for each cognitive domain and feature populations from ethnocultural groups and geographical regions for which we lacked data.

Prevalence Rates of Dementia and Mild Cognitive Impairment Are Affected by the Diagnostic Parameter Changes for Neurocognitive Disorders in the DSM-5 in a Korean Population.

AIM: To examine the impact of the revised diagnostic criteria for neurocognitive disorders (NCDs) in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) on the prevalence of dementia and mild cognitive impairment (MCI). METHODS: A total of 755 participants aged 65 years or older in the Nationwide Survey on Dementia Epidemiology in Korea 2012 were rediagnosed according to the DSM-5 criteria. RESULTS: The estimated age-, gender-, education-, and urbanicity-standardized prevalence rates of major and mild NCDs were 8.35 and 11.10%, respectively, and those of dementia and MCI were 8.74 and 31.85%, respectively. Cohen's κ for dementia and major NCD was 0.988, and that for MCI and mild NCD was 0.273. CONCLUSION: Diagnostic discrepancies between major/mild NCDs and dementia/MCI might depend on the operationalization of neuropsychological performance criteria.