Hugh C. Hendrie

Global prevalence of dementia: a Delphi consensus study.

BACKGROUND 100 years after the first description, Alzheimers disease is one of the most disabling and burdensome health conditions worldwide. We used the Delphi consensus method to determine dementia prevalence for each world region. METHODS 12 international experts were provided with a systematic review of published studies on dementia and were asked to provide prevalence estimates for every WHO world region, for men and women combined, in 5-year age bands from 60 to 84 years, and for those aged 85 years and older. UN population estimates and projections were used to estimate numbers of people with dementia in 2001, 2020, and 2040. We estimated incidence rates from prevalence, remission, and mortality. FINDINGS Evidence from well-planned, representative epidemiological surveys is scarce in many regions. We estimate that 24.3 million people have dementia today, with 4.6 million new cases of dementia every year (one new case every 7 seconds). The number of people affected will double every 20 years to 81.1 million by 2040. Most people with dementia live in developing countries (60% in 2001, rising to 71% by 2040). Rates of increase are not uniform; numbers in developed countries are forecast to increase by 100% between 2001 and 2040, but by more than 300% in India, China, and their south Asian and western Pacific neighbours. INTERPRETATION We believe that the detailed estimates in this paper constitute the best currently available basis for policymaking, planning, and allocation of health and welfare resources.

Six-item screener to identify cognitive impairment among potential subjects for clinical research.

Objective. To design a brief cognitive screener with acceptable sensitivity and specificity for identifying subjects with cognitive impairment Design. Cohort one is assembled from a community-based survey coupled with a second-stage diagnostic evaluation using formal diagnostic criteria for dementia. Cohort two is assembled from referrals to a specialty clinic for dementing disorders that completed the same diagnostic evaluation. Setting. Urban neighborhoods in Indianapolis, Indiana and the Indiana Alzheimer Disease Center. Patients. Cohort one consists of 344 community-dwelling black persons identified from a random sample of 2212 black persons aged 65 and older residing in Indianapolis; cohort two consists of 651 subject referrals to the Alzheimer Disease Center. Measurements. Formal diagnostic clinical assessments for dementia including scores on the Mini-mental state examination (MMSE), a six-item screener derived from the MMSE, the Blessed Dementia Rating Scale (BDRS), and the Word List Recall. Based on clinical evaluations, subjects were categorized as no cognitive impairment, cognitive impairment-not demented, or demented. Results. The mean age of the community-based sample was 74.4 years, 59.4% of the sample were women, and the mean years of education was 10.1. The prevalence of dementia in this sample was 4.3% and the prevalence of cognitive impairment was 24.6%. Using a cut-off of three or more errors, the sensitivity and specificity of the six-item screener for a diagnosis of dementia was 88.7 and 88.0, respectively. In the same sample, the corresponding sensitivity and specificity for the MMSE using a cut-off score of 23 was 95.2 and 86.7. The performance of the two scales was comparable across the two populations studied and using either cognitive impairment or dementia as the gold standard. An increasing number of errors on the six-item screener is highly correlated with poorer scores on longer measures of cognitive impairment. Conclusions. The six-item screener is a brief and reliable instrument for identifying subjects with cognitive impairment and its diagnostic properties are comparable to the full MMSE. It can be administered by telephone or face-to-face interview and is easily scored by a simple summation of errors.

Epidemiology of Dementia and Alzheimer's Disease

The prevalence of dementia in subjects 65 years and older in North America is approximately 6%-10%, with Alzheimers disease (AD) accounting for two-thirds of these cases. If milder cases are included, the prevalence rates double. Both causative and associative genes for AD have now been identified. The search for nongenetic risk factors has been less conclusive. Only age and family history of dementia are consistently associated with AD in all studies, but putative, protective agents such as estrogen, nonsteroidal anti-inflammatory agents (NSAIDs), and vitamin E are now undergoing clinical trials.

Prevalence of cognitive impairment Data from the Indianapolis Study of Health and Aging

Background: The epidemiology and natural history of cognitive impairment that is not dementia is important to the understanding of normal aging and dementia. Objective: To determine the prevalence and outcome of cognitive impairment that is not dementia in an elderly African American population. Method: A two-phase, longitudinal study of aging and dementia. A total of 2212 community-dwelling African American residents of Indianapolis, IN, aged 65 and older were screened, and a subset (n = 351) received full clinical assessment and diagnosis. Subsets of the clinically assessed were seen again for clinical assessment and rediagnosis at 18 and 48 months. Weighted logistic regression was used to generate age-specific prevalence estimates. Results: The overall rate of cognitive impairment among community-dwelling elderly was 23.4%. Age-specific rates indicate increasing prevalence with increasing age: 19.2% for ages 65 to 74 years, 27.6% for ages 75 to 84 years, and 38.0% for ages 85+ years. The most frequent cause of cognitive impairment was medically unexplained memory loss with a community prevalence of 12.5%, followed by medical illness–associated cognitive impairment (4.0% prevalence), stroke (3.6% prevalence), and alcohol abuse (1.5% prevalence). At 18-month follow-up, 26% (17/66) of the subjects had become demented. Conclusions: Cognitive impairment short of dementia affects nearly one in four community-dwelling elders and is a major risk factor for later development of dementia.

The NIH Cognitive and Emotional Health Project

The Cognitive and Emotional Health Project (CEHP) seeks to identify the demographic, social, and biological determinants of cognitive and emotional health in the older adult. As part of the CEHP, a critical evaluation study committee was formed to assess the state of epidemiological research on demographic, social, and biological determinants of cognitive and emotional health.

Performance of the PHQ-9 as a Screening Tool for Depression After Stroke

Background and Purpose— The purpose of this study was to examine the performance of the Patient Health Questionnaire (PHQ)-9, a 9-item depression scale, as a screening and diagnostic instrument for assessing depression in stroke survivors. Methods— As part of a randomized treatment trial for poststroke depression (PSD), subjects with and without PSD completed the PHQ-9, a 9-item summed scale, with scores ranging from 0 (no depressive symptoms) to 27 (all symptoms occurring daily). Subjects endorsing 2 or more symptoms of depression were administered the criterion standard Structured Clinical Interview for Depression (SCID). Receiver operating characteristic analysis was used to examine the sensitivity and specificity of the PHQ-9 Results— Of 316 subjects enrolled, 145 met SCID criteria for major depression or other depressive disorder, and 171 were not depressed. PHQ-9 scores discriminated well between subjects with any versus no depressive disorder, with an area under the curve (AUC) of 0.96, as well as between subjects with and without major depression (AUC=0.96). The AUC was similar regardless of patient age, gender, or ethnicity. A PHQ-9 score ≥10 had 91% sensitivity and 89% specificity for major depression, and 78% sensitivity and 96% specificity for any depression diagnosis. Conclusions— The PHQ-9 performs well as a brief screener for PSD with operating characteristics similar or superior to other depression measures and similar to its characteristics in a primary care population. Moreover, PHQ-9 scores discriminate equally well between those with and without PSD regardless of age, gender, or ethnicity.

Comorbidity profile of dementia patients in primary care: Are they sicker?

OBJECTIVES: To compare the medical comorbidity of older patients with and without dementia in primary care.

Improving depression care for older, minority patients in primary care

Objective:Few older minorities receive adequate treatment of depression in primary care. This study examines whether a collaborative care model for depression in primary care is as effective in older minorities as it is in nonminority elderly patients in improving depression treatment and outcomes. Study Design:A multisite randomized clinical trial of 1801 older adults comparing collaborative care for depression with treatment as usual in primary care. Twelve percent of the sample were black (n = 222), 8% were Latino (n = 138), and 3% (n = 53) were from other minority groups. We compared the 3 largest ethnic groups (non-Latino white, black, and Latino) on depression severity, quality of life, and mental health service use at baseline, 3, 6, and 12 months after randomization to collaborative care or usual care. Principal Findings:Compared with care as usual, collaborative care significantly improved rates and outcomes of depression care in older adults from ethnic minority groups and in older whites. At 12 months, intervention patients from ethnic minorities (blacks and Latinos) had significantly greater rates of depression care for both antidepressant medication and psychotherapy, lower depression severity, and less health-related functional impairment than usual care participants (64%, 95% confidence interval [CI] 55–72 versus 45%, CI 36–55, P = 0.003 for antidepressant medication; 37%, CI 28–47 versus 13%, CI 6–19, P = 0.002 for psychotherapy; mean = 0.9, CI 0.8–1.1 versus mean = 1.4, CI 1.3–1.5, P < 0.001 for depression severity, range 0–4; mean = 3.7, CI 3.2–4.1, versus mean = 4.7, CI 4.3–5.1, P < 0.0001 for functional impairment, range 0–10). Conclusions:Collaborative Care is significantly more effective than usual care for depressed older adults, regardless of their ethnicity. Intervention effects in ethnic minority participants were similar to those observed in whites.

Treatment of depression improves physical functioning in older adults

Objectives: To determine the effect of collaborative care management for depression on physical functioning in older adults.

Alcohol related dementia: Proposed clinical criteria

Current diagnostic criteria for Alcohol Related Dementia (ARD) are based almost exclusively on clinical judgment. Moreover, there are no guidelines available to assist the clinician or the researcher in distinguishing Alcohol Related Dementia from other causes of dementia such as Alzheimers Disease (AD). However, this distinction may have implications for the prognosis and treatment of patients. In this article, provisional diagnostic criteria for establishing a diagnosis of Alcohol Related Dementia are proposed for further study. The criteria are based on the available literature on the relationship between alcohol consumption and dementia and were modeled after existing diagnostic criteria for AD and Vascular Dementia. Validity of these criteria for distinguishing AD from ARD will require further study.