Population-based analysis of cholesteryl ester transfer protein identifies association between I405V and cognitive decline: the Cache County Study

Cholesterol has been implicated in the pathogenesis of late-onset Alzheimer's disease (LOAD) and the cholesteryl ester transfer protein (CETP) is critical to cholesterol regulation within the cell, making CETP an Alzheimer's disease candidate gene. Several studies have suggested that CETP I405V (rs5882) is associated with cognitive function and LOAD risk, but findings vary and most studies have been conducted using relatively small numbers of samples. To test whether this variant is involved in cognitive function and LOAD progression, we genotyped 4486 subjects with up to 12 years of longitudinal cognitive assessment. Analyses revealed an average 0.6-point decrease per year in the rate of cognitive decline for each additional valine (p < 0.011). We failed to detect the association between CETP I405V and LOAD status (p < 0.28). We conclude that CETP I405V is associated with preserved cognition over time but is not associated with LOAD status.

Mitochondrial genomic variation associated with higher mitochondrial copy number: the Cache County Study on Memory Health and Aging

Background

The mitochondria are essential organelles and are the location of cellular respiration, which is responsible for the majority of ATP production. Each cell contains multiple mitochondria, and each mitochondrion contains multiple copies of its own circular genome. The ratio of mitochondrial genomes to nuclear genomes is referred to as mitochondrial copy number. Decreases in mitochondrial copy number are known to occur in many tissues as people age, and in certain diseases. The regulation of mitochondrial copy number by nuclear genes has been studied extensively. While mitochondrial variation has been associated with longevity and some of the diseases known to have reduced mitochondrial copy number, the role that the mitochondrial genome itself has in regulating mitochondrial copy number remains poorly understood.

Results

We analyzed the complete mitochondrial genomes from 1007 individuals randomly selected from the Cache County Study on Memory Health and Aging utilizing the inferred evolutionary history of the mitochondrial haplotypes present in our dataset to identify sequence variation and mitochondrial haplotypes associated with changes in mitochondrial copy number. Three variants belonging to mitochondrial haplogroups U5A1 and T2 were significantly associated with higher mitochondrial copy number in our dataset.

Conclusions

We identified three variants associated with higher mitochondrial copy number and suggest several hypotheses for how these variants influence mitochondrial copy number by interacting with known regulators of mitochondrial copy number. Our results are the first to report sequence variation in the mitochondrial genome that causes changes in mitochondrial copy number. The identification of these variants that increase mtDNA copy number has important implications in understanding the pathological processes that underlie these phenotypes.

Rare coding variants in the phospholipase D3 gene confer risk for Alzheimer's disease

Genome-wide association studies (GWAS) have identified several risk variants for late-onset Alzheimer's disease (LOAD). These common variants have replicable but small effects on LOAD risk and generally do not have obvious functional effects. Low-frequency coding variants, not detected by GWAS, are predicted to include functional variants with larger effects on risk. To identify low-frequency coding variants with large effects on LOAD risk, we carried out whole-exome sequencing (WES) in 14 large LOAD families and follow-up analyses of the candidate variants in several large LOAD case-control data sets. A rare variant in PLD3 (phospholipase D3; Val232Met) segregated with disease status in two independent families and doubled risk for Alzheimer's disease in seven independent case-control series with a total of more than 11,000 cases and controls of European descent. Gene-based burden analyses in 4,387 cases and controls of European descent and 302 African American cases and controls, with complete sequence data for PLD3, reveal that several variants in this gene increase risk for Alzheimer's disease in both populations. PLD3 is highly expressed in brain regions that are vulnerable to Alzheimer's disease pathology, including hippocampus and cortex, and is expressed at significantly lower levels in neurons from Alzheimer's disease brains compared to control brains. Overexpression of PLD3 leads to a significant decrease in intracellular amyloid-β precursor protein (APP) and extracellular Aβ42 and Aβ40 (the 42- and 40-residue isoforms of the amyloid-β peptide), and knockdown of PLD3 leads to a significant increase in extracellular Aβ42 and Aβ40. Together, our genetic and functional data indicate that carriers of PLD3 coding variants have a twofold increased risk for LOAD and that PLD3 influences APP processing. This study provides an example of how densely affected families may help to identify rare variants with large effects on risk for disease or other complex traits.

The Cache County Study on Memory in Aging: factors affecting risk of Alzheimer's disease and its progression after onset

The Cache County Study on Memory in Aging is a longitudinal, population-based study of Alzheimer's disease (AD) and other dementias. Initiated in 1995 and extending to 2013, the study has followed over 5,000 elderly residents of Cache County, Utah (USA) for over twelve years. Achieving a 90% participation rate at enrolment, and spawning two ancillary projects, the study has contributed to the literature on genetic, psychosocial and environmental risk factors for AD, late-life cognitive decline, and the clinical progression of dementia after its onset. This paper describes the major study contributions to the literature on AD and dementia.

Stressful life events and cognitive decline in late life: moderation by education and age. The Cache County Study

OBJECTIVE

Stressful life events (SLE) have been associated with increased dementia risk, but their association with cognitive decline has been inconsistent. In a longitudinal population-based study of older individuals, we examined the association between SLE and cognitive decline, and the role of potential effect modifiers.

METHODS

A total of 2665 non-demented participants of the Cache County Memory Study completed an SLE questionnaire at Wave 2 and were revisited 4 and 7 years later. The events were represented via several scores: total number, subjective rating (negative, positive, and unexpected), and a weighted summary based on their impact. Cognition was assessed at each visit with the modified Mini-Mental State Exam. General linear models were used to examine the association between SLE scores and cognition. Effect modification by age, education, and APOE genotype was tested.

RESULTS

Years of formal education (p = 0.006) modified the effect of number of SLE, and age (p = 0.009) modified the effect of negative SLE on the rate of cognitive decline. Faster decline was observed among those with fewer years of education experiencing more SLE and also among younger participants experiencing more negative SLE. There was no association between other indicators of SLE and cognitive decline. APOE genotype did not modify any of the aforementioned associations.

CONCLUSIONS

The effects of SLE on cognition in late life are complex and vary by individual factors such as age and education. These results may explain some of the contradictory findings in the literature.

Baseline disability in activities of daily living predicts dementia risk even after controlling for baseline global cognitive ability and depressive symptoms

OBJECTIVES

Late-life disability in activities of daily living (ADL) is theorized to be driven by underlying cognitive and/or physical impairment, interacting with psychological and environmental factors. Although we expect that cognitive deficits would explain associations between ADL disability and dementia risk, the current study examined ADL as a predictor of future dementia after controlling for global cognitive status.

METHODS

The population-based Cache County Memory Study (N = 3547) assessed individuals in four triennial waves (average age 74.9 years, years of education 13.36 years; 57.9% were women). Cox proportional hazards regression models assessed whether baseline ADL disability (presence of 2+ Instrumental ADL and/or 1+ Personal ADL) predicted incident dementia after controlling for APOE status, gender, age, baseline cognitive ability (Modified Mini-mental State Exam, 3MS-R; adjusted for education level), and baseline depressive symptoms (Diagnostic Interview Schedule).

RESULTS

Over the course of study, 571 cases of incident dementia were identified through in-depth cognitive assessment, ending in expert consensus diagnosis. Results from Cox models suggest that ADL disability is a statistically significant predictor of incident dementia (adjusted hazard ratio = 1.83, p < 0.001), even after controlling for covariates.

CONCLUSIONS

Findings suggest that ADL disability offers unique contributions in risk for incident dementia, even after controlling for global cognitive status. We discuss how physical impairment and executive function may play important roles in this relationship, and how ADL is useful, not just a diagnostic tool at, or after dementia onset, but also as a risk factor for future dementia, even in individuals not impaired on global cognitive tests.

Predictors of dementia caregiver depressive symptoms in a population: the Cache County dementia progression study

OBJECTIVES

Previous research has consistently reported elevated rates of depressive symptoms in dementia caregivers, but mostly with convenience samples. This study examined rates and correlates of depression at the baseline visit of a population sample of dementia caregivers (N = 256).

METHOD

Using a modified version of Williams (Williams, I. C. [2005]. Emotional health of black and white dementia caregivers: A contextual examination. The Journals of Gerontology, Series B: Psychological Sciences and Social Sciences, 60, P287-P295) ecological contextual model, we examined 5 contexts that have contributed to dementia caregiver depression. A series of linear regressions were performed to determine correlates of depression.

RESULTS

Rates of depressive symptoms were lower than those reported in most convenience studies. We found fewer depressive symptoms in caregivers with higher levels of education and larger social support networks, fewer health problems, greater likelihood of using problem-focused coping, and less likelihood of wishful thinking and with fewer behavioral disturbances in the persons with dementia.

DISCUSSION

These results suggest that depression may be less prevalent in populations of dementia caregivers than in clinic-based samples, but that the correlates of depression are similar for both population and convenience samples. Interventions targeting individuals with small support networks, emotion-focused coping styles, poorer health, low quality of life, and those caring for persons with higher numbers of behavioral problems need development and testing.

Mitochondrial genomic analysis of late onset Alzheimer's disease reveals protective haplogroups H6A1A/H6A1B: the Cache County Study on Memory in Aging

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia and AD risk clusters within families. Part of the familial aggregation of AD is accounted for by excess maternal vs. paternal inheritance, a pattern consistent with mitochondrial inheritance. The role of specific mitochondrial DNA (mtDNA) variants and haplogroups in AD risk is uncertain.

METHODOLOGY/PRINCIPAL FINDINGS

We determined the complete mitochondrial genome sequence of 1007 participants in the Cache County Study on Memory in Aging, a population-based prospective cohort study of dementia in northern Utah. AD diagnoses were made with a multi-stage protocol that included clinical examination and review by a panel of clinical experts. We used TreeScanning, a statistically robust approach based on haplotype networks, to analyze the mtDNA sequence data. Participants with major mitochondrial haplotypes H6A1A and H6A1B showed a reduced risk of AD (p=0.017, corrected for multiple comparisons). The protective haplotypes were defined by three variants: m.3915G>A, m.4727A>G, and m.9380G>A. These three variants characterize two different major haplogroups. Together m.4727A>G and m.9380G>A define H6A1, and it has been suggested m.3915G>A defines H6A. Additional variants differentiate H6A1A and H6A1B; however, none of these variants had a significant relationship with AD case-control status.

CONCLUSIONS/SIGNIFICANCE

Our findings provide evidence of a reduced risk of AD for individuals with mtDNA haplotypes H6A1A and H6A1B. These findings are the results of the largest study to date with complete mtDNA genome sequence data, yet the functional significance of the associated haplotypes remains unknown and replication in others studies is necessary.

Effects of Food and Drug Administration-approved medications for Alzheimer's disease on clinical progression

BACKGROUND

Observational studies suggest that cholinesterase inhibitors and/or memantine may delay clinical progression of Alzheimer's disease (AD) in 40% of individuals taking the medications. Given this response and existence of side effects, we sought to quantify medication use and benefits in a population-based study of incident AD cases.

METHODS

The Cache County Dementia Progression Study enrolled and followed a cohort of 327 incident AD cases for a maximum of 9 years. Drug exposure was expressed using a persistency index (PI), calculated as total years of drug use divided by total years of observation. Linear mixed-effects models examined PI, and interactions with sex and apolipoprotein E (APOE) as predictors of clinical progression on the Mini-Mental State Examination and Clinical Dementia Rating-Sum of Boxes.

RESULTS

A total of 69 participants (21.1%) reported having ever used cholinesterase inhibitors or memantine. There was a strong three-way interaction between PI, sex, and time. Among women, a higher PI (i.e., greater duration of use) of cholinesterase inhibitors was associated with slower progression on the Mini-Mental State Examination and Clinical Dementia Rating-Sum of Boxes, particularly among those with an APOE ɛ4 allele. In contrast, higher PI was associated with faster progression in males.

CONCLUSION

A low percentage of individuals with AD in the community are taking cholinesterase inhibitors or memantine. This study suggests that women, particularly those with an APOE ɛ4 allele, may benefit the most from these medications. With the newly approved increased dose of donepezil, it will be imperative to determine whether a higher dose is needed in men or whether other factors warrant consideration.

Interaction between vascular factors and the APOE ε4 allele in predicting rate of progression in Alzheimer's disease

Vascular factors have been shown to affect the rate of Alzheimer's disease (AD) progression. However, the effect of the APOE ε4 allele on rate of progression has been ambiguous. Little research to date has examined an interaction between vascular factors and the APOE ε4 allele in predicting decline among AD patients. 216 participants with incident AD from a population of elderly persons in Cache County, Utah, were followed for a mean of 3.3 years and 4.2 follow-up visits. A history of vascular risk factors and conditions and anti-hypertensive use was assessed at the diagnostic visit. Linear mixed effects models tested interactions between the vascular factors, APOE ε4, and time as predictors of clinical progression on the Mini-Mental State Exam (MMSE) and Clinical Dementia Rating-Sum of Boxes (CDR-SB). Multiple comparisons were corrected using the Holm-Bonferroni method. There was a 3-way interaction between stroke, APOE ε4 and time in predicting MMSE decline (LR χ² = 10.32, 2 df, p = 0.006). For the CDR-SB, there were 3-way interactions between the APOE ε4, time and either myocardial infarction (LR χ² = 17.83, 2 df, p = 0.0001) or stroke (LR χ² = 11.48, 2 df, p = 0.003. Results suggest a complex relationship between the APOE ε4 and vascular factors in predicting cognitive and functional progression. Among individuals with a history of stroke or myocardial infarction at baseline, progression of AD is influenced by APOE ε4 carrier status and varies by time after AD diagnosis.

Intracranial volume and dementia: some evidence in support of the cerebral reserve hypothesis

The brain reserve hypothesis has been posited as being one important mediating factor for developing dementia, especially Alzheimer's disease (AD). Evidence for this hypothesis is mixed though different methodologies have made these findings difficult to interpret. We examined imaging data from a large cohort (N=194) of mixed dementia patients and controls, 65years old and older from the Cache County, Utah Study of Memory and Aging for evidence of the brain reserve hypothesis using total intracranial volume (TICV) as a quantitative measure of pre-morbid brain size and a vicarious indicator of reserve. A broader spectrum of non-demented elderly control subjects from previous studies was also included for comparison (N=423). In addition, non-parametric Classification and Regression Tree (CART) analyses were performed to model group heterogeneity and identify any subgroups of patients where TICV might be an important predictor of dementia. Parametrically, no main effect was found for TICV when predicting a dementia diagnosis; however, the CART analysis did reveal important TICV subgroups, including a sex differential wherein ε4 APOE allele presence in males and low TICV predicted AD classification. TICV, APOE, and other potential mediator/moderator variables are discussed in the context of the brain reserve hypothesis.

Greater risk of dementia when spouse has dementia? The Cache County study

OBJECTIVES

To examine the effects of caring for a spouse with dementia on the caregiver's risk for incident dementia.

DESIGN

Population-based study of incident dementia in spouses of persons with dementia.

SETTING

Rural county in northern Utah.

PARTICIPANTS

Two thousand four hundred forty-two subjects (1,221 married couples) aged 65 and older.

MEASUREMENTS

Incident dementia was diagnosed in 255 subjects, with onset defined as age when subject met Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised, criteria for dementia. Cox proportional hazards regression tested the effect of time-dependent exposure to dementia in one's spouse, adjusted for potential confounders.

RESULTS

A subject whose spouse experienced incident dementia onset had a six times greater risk for incident dementia as subjects whose spouses were dementia free (hazard rate ratio (HRR)=6.0, 95% confidence interval (CI)=2.2-16.2, P<.001). In sex-specific analyses, husbands had higher risks (HRR=11.9, 95% CI=1.7-85.5, P=.01) than wives (HRR=3.7, 95% CI=1.2-11.6, P=.03).

CONCLUSION

The chronic and often severe stress associated with dementia caregiving may exert substantial risk for the development of dementia in spouse caregivers. Additional (not mutually exclusive) explanations for findings are discussed.

A brief metacognition questionnaire for the elderly: comparison with cognitive performance and informant ratings the Cache County Study

OBJECTIVE

To examine the utility of a brief, metacognition questionnaire by examining its association with objective cognitive testing and informant ratings. We hypothesized that the association between self-ratings of change and both outcomes would be greater among individuals without dementia than among those with dementia.

METHODS

Participants were 535 persons without dementia and 152 with dementia from the Cache County Memory Study who had completed a metacognition questionnaire, two administrations of the Modified Mini-Mental State Exam (3 MS) and who had data on the Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE). Cronbach's alpha was calculated as a measure of internal consistency of the metacognition questionnaire. Multiple regression was used to examine the relationship between metacognition and 3 MS change. Logistic regression was used to examine the relationship between metacognition and IQCODE ratings (no change vs. worse).

RESULTS

Cronbach's alpha was 0.75. Among individuals without dementia, metacognition significantly predicted 3 MS change (p = .027) and IQCODE ratings (OR = 4.0, 95% CI = 1.2-13.8, p = .029), suggesting consistency among measures. For those with dementia, there was a weak, inverse relationship between 3 MS change and metacognition (r = -0.16, p = .056). IQCODE ratings were not significantly associated with metacognition (p = .729). Degree of dementia severity did not modify the relationship between metacognition and either outcome (p > .05).

CONCLUSIONS

We demonstrated adequate internal consistency and evidence for validity of a brief metacognition questionnaire. The questionnaire may provide a useful adjunct to memory and functional assessments for assessing anosognosia in elderly populations.

Identification of VaD and AD prodromes: the Cache County Study

BACKGROUND

It is unclear whether vascular dementia (VaD) has a cognitive prodrome, akin to the mild cognitive impairment (MCI) prodrome to Alzheimer's dementia (AD). To evaluate whether VaD has a cognitive prodrome, and if it can be differentiated from prodromal AD, we examined neuropsychological test performance of participants in a nested case-control study within a population-based cohort aged 65 or older.

METHODS

Participants (n = 485) were identified from the Cache County Study, a large population-based study of aging and dementia. After an average of 3 years of follow-up, a total of 62 incident dementia cases were identified (14 VaD, 48 AD). We identified a number of neuropsychological tests (executive and memory) that discriminated between diagnosed VaD and AD cases. Multivariate analyses sought to differentiate between these same groups 3 years before clinical diagnosis.

RESULTS

The Consortium to Establish a Registry for Alzheimer's Disease Word List Recognition Test correct recognition of foils (mean difference, 1.25; 95% confidence interval [CI], 0.42 to 2.07; p < 0.01), Logical Memory I (mean difference, 7.16; 95% CI, 0.78 to 13.55, p < 0.05), Logical Memory II delayed recall (mean difference, 8.67; 95% CI, 1.59 to 15.74, p < 0.05), and percent savings (mean difference, 51.07; 95% CI, 32.58 to 69.56, p < 0.0001) differentiated VaD from AD cases after adjustment for age, sex, education, and dementia severity. Three years before dementia diagnosis, word list recognition ("no" responses mean difference, 1.40; 95% CI, 0.64 to 2.17; p < 0.001, and "yes" responses mean difference, -1.14; 95% CI, -2.14 to -0.13; p < 0.03) discriminated between prodromal VaD and AD.

CONCLUSION

These results suggest that VaD has a prodromal syndrome, the cognitive features of which are distinguishable from the cognitive prodrome of AD.

Comparison of clinical and neuropathologic diagnoses of Alzheimer's disease in 3 epidemiologic samples

BACKGROUND

Studies of dementia in populations avoid many of the selection biases in clinical samples but require special evaluation and diagnostic methods to obtain high participation rates. To address this issue, we developed a unique in-home dementia assessment. We assessed validity of these assessments using neuropathologic confirmation of the clinical diagnosis in 3 epidemiologic samples.

METHODS

Subjects were 175 participants in 3 ongoing studies of dementia. Two were population based and identified dementia by cognitive screening. The third study sought volunteers via advertisements. Dementia evaluations were then conducted at the participants' residences by specially trained nurses and psychometricians. Evaluation results were interpreted, and preliminary diagnoses were assigned by a geropsychiatrist or neurologist and a psychologist. Final diagnoses were assigned by a consensus panel of neurologists, geropsychiatrists, and psychologists. We compared the clinical diagnoses with the gold-standard neuropathologic diagnoses for those participants who subsequently underwent autopsy.

RESULTS

Among the demented, the sensitivity of a clinical diagnosis of probable or possible Alzheimer's disease (AD) was 93% across the 3 studies. The rate of overall diagnostic agreement was 81%. Measures of agreement did not differ meaningfully across varying levels of dementia severity.

CONCLUSIONS

Rates of neuropathologic confirmation for clinical AD diagnoses in these studies were similar to those reported from clinic-based samples. These results support the validity of clinical diagnoses of AD from a structured in-home assessment of community dwelling and institutionalized individuals using relatively economical methods of dementia screening and assessment.

Neuropsychological performance in advanced age: influences of demographic factors and Apolipoprotein E: findings from the Cache County Memory Study

The Cache County Study of Memory in Aging (CCMS) is an epidemiological study of Alzheimer's disease (AD), mild cognitive disorders, and aging in a population of exceptionally long-lived individuals (7th to 11th decade). Observation of population members without dementia provides an opportunity for establishing the range of normal neurocognitive performance in a representative sample of the very old. We examined neurocognitive performance of the normal participants undergoing full clinical evaluations (n = 507) and we tested the potential modifying effects of apolipoprotein E (APOE) genotype, a known genetic risk factor for the later development of AD. The results indicate that advanced age and low education are related to lower test scores across nearly all of the neurocognitive measures. Gender and APOE epsilon4 both had negligible and inconsistent influences, affecting only isolated measures of memory and expressive speech (in case of gender). The gender and APOE effects disappeared once age and education were controlled. The study of this exceptionally long-lived population provides useful normative information regarding the broad range of "normal" cognition seen in advanced age. Among elderly without dementia or other cognitive impairment, APOE does not appear to exert any major effects on cognition once other demographic influences are controlled.

Does NSAID use modify cognitive trajectories in the elderly?: The Cache County Study

BACKGROUND

Epidemiologic studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) may be useful for the prevention of Alzheimer disease (AD). By contrast, clinical trials have not supported NSAID use to delay or treat AD. Few studies have evaluated cognitive trajectories of NSAID users over time.

METHODS

Residents of Cache County, UT, aged 65 or older on January 1, 1995, were invited to participate in the study. At baseline, participants provided a detailed inventory of their medications and completed a revised Modified Mini-Mental State Examination (3MS). Participants (n = 3,383) who were cognitively normal at baseline were re-examined after 3 and 8 years. The association between NSAID use and 3MS scores over time was estimated using random effects modeling.

RESULTS

Associations depended upon when NSAIDs were started and APOE genotype. In participants who started NSAID use prior to age 65, those with no APOE epsilon4 alleles performed similarly to nonusers (a difference of 0.10 points per year; p = 0.19), while those with one or more epsilon4 allele(s) showed more protection (0.40 points per year; p = 0.0005). Among participants who first used NSAIDs at or after age 65, those with one or more epsilon4 alleles had higher baseline scores (0.95 points; p = 0.03) but did not show subsequent difference in change in score over time (0.06 points per year; p = 0.56). Those without an epsilon4 allele who started NSAID use after age 65 showed greater decline than nonusers (-0.16 points per year; p = 0.02).

CONCLUSIONS

Nonsteroidal anti-inflammatory drug use may help to prevent cognitive decline in older adults if started in midlife rather than late life. This effect may be more notable in those who have one or more APOE epsilon4 alleles.

Epidemiology of apathy in older adults: the Cache County Study

OBJECTIVES

The objectives of this study are to describe the distribution of apathy in community-based older adults and to investigate its relationships with cognition and day-to-day functioning.

METHODS

Data from the Cache County Study on Memory, Health and Aging were used to estimate the frequency of apathy in groups of elders defined by demographic, cognitive, and functional status and to examine the associations of apathy with impairments of cognition and day-to-day functioning.

RESULTS

Apathy was measured with the Neuropsychiatric Inventory. Clinical apathy (Neuropsychiatric Inventory score > or = 4) was found in 1.4% of individuals classified as cognitively normal, 3.1% of those with a mild cognitive syndrome, and 17.3% of those with dementia. Apathy status was associated with cognitive and functional impairments and higher levels of stress experienced by caregivers. Among participants with normal cognition, apathy was associated with worse performance on the Mini-Mental State Examination, the Boston Naming and Animal Fluency tests, and the Trail Making Test-Part B. The association of apathy with cognitive impairment was independent of its association with Neuropsychiatric Inventory depression.

CONCLUSIONS

In a cohort of community-based older adults, the frequency and severity of apathy is positively correlated with the severity of cognitive impairment. In addition, apathy is associated with cognitive and functional impairments in elders adjudged to have normal cognition. The results suggest that apathy is an early sign of cognitive decline and that delineating phenotypes in which apathy and a mild cognitive syndrome co-occur may facilitate earlier identification of individuals at risk for dementia.