Letter and Semantic Fluency in Older Adults: Effects of Mild Depressive Symptoms and Age-Stratified Normative Data

Depressive Symptoms are Associated with Decline Over Time in Verbal Fluency Performance in Female but Not Male Community-Dwelling Older Adults

OBJECTIVE

The current study was designed to examine associations between depressive symptoms and longitudinal declines in category and letter fluency performance in a gender-stratified sample of older adults.

METHOD

Participants were community-residing older adults (females: n = 289; males: n = 233) followed annually (2011-2018) as part of a cohort study conducted at Albert Einstein College of Medicine in New York. Depressive symptoms were assessed using the Geriatric Depression Scale (GDS). Standard forms assessed category and letter fluency performance. Participants were dementia-free during study enrollment.

RESULTS

The presence of baseline depressive symptoms suggestive of subclinical depression was associated with a worse longitudinal decline in category fluency performance in female but not male participants. These associations remained significant when excluding participants with prevalent and incident mild cognitive impairment and incident dementia. Irrespective of gender, letter fluency performance did not decline over time and was not influenced by the presence of depressive symptoms.

DISCUSSION

The present study's results can aid in identification of older adults who may be at greater risk for cognitive decline, and add to the limited literature examining the influence of gender on longitudinal associations between depressive symptoms and verbal fluency performance.

A Systematic Review of Normative Data for Verbal Fluency Test in Different Languages

Verbal fluency tests are easy and quick to use in neuropsychological assessments, so they have been counted among the most classical tools in this context. To date, several normative data for verbal fluency tests have been provided in different languages and countries. A systematic review was carried out with studies that provide normative data for verbal fluency tests. Studies were collected from Scopus, PubMed and Web of Science. 183 studies were retrieved from the database search, of which 73 finally met the inclusion criteria. An analysis of the risk of bias regarding samples selection/characterization and procedure/results reports is conducted for each article. Finally, a full description of the normative data characteristics, considering country and language, verbal fluency task characteristics (type of task) and sample characteristics (number of subjects, gender, age, education) is included. The current systematic review provides an overview and analysis of internationally published normative data that might help clinicians in their search for valid and useful norms on verbal fluency tasks, as well as updated information about qualitative aspects of the different options currently available.

Normative Data for Single-Letter Controlled Oral Word Association Test in Older White Australians and Americans, African-Americans, and Hispanic/Latinos

Background

The Controlled Oral Word Association Test (COWAT) is a commonly used measure of verbal fluency. While a normal decline in verbal fluency occurs in late adulthood, significant impairments may indicate brain injury or diseases such as Alzheimer's disease. Normative data is essential to identify when test performance falls below expected levels based on age, gender, and education level.

Objective

This study aimed to establish normative performance data on single-letter COWAT for older community-dwelling adults.

Methods

Over 19,000 healthy men and women, without a diagnosis of dementia or a Modified Mini-Mental State Examination score below 77/100, were recruited for the ASPREE trial. Neuropsychological assessments, including the COWAT with letter F, were administered at study entry.

Results

Median participant age was 75 years (range 65-98), with 56.5% being women. The majority of participants had 9-11 years of education in Australia and over 12 years in the U.S. The COWAT performance varied across ethno-racial groups and normative data were thus presented separately for 16,335 white Australians, 1,084 white Americans, 896 African-Americans, and 316 Hispanic/Latinos. Women generally outperformed men in the COWAT, except for Hispanic/Latinos. Higher education levels consistently correlated with better COWAT performance across all groups, while the negative association with age was weaker.

Conclusions

This study provides comprehensive normative data for the COWAT stratified by ethno-racial groups in Australia and the U.S., considering age, gender, and education level. These norms can serve as reference standards for screening cognitive impairments in older adults in both clinical and research settings.

The role of semantic assessment in the differential diagnosis between late-life depression and Alzheimer's disease or amnestic mild cognitive impairment: systematic review and meta-analysis

OBJECT

The cognitive complaints encountered in late-life depression (LLD) make it difficult to distinguish from amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD) based on an analysis of neurocognitive disorders. The hypothesis of the early impairment of semantic memory in AD and aMCI is considered a potential differential cognitive clue, but the absence of this impairment has not yet been confirmed in  LLD.

METHOD

Based on the PRISMA method, we systematically seek neuropsychological assessments of individuals with LLD, the present study included 31 studies representing 3291 controls and 2820 people with LLD. Wherever possible, studies that tested simultaneously groups with LLD, AD (or aMCI) were also included. The results of the group of neuropsychological tasks relying on semantic memory were analyzed in two groups of tasks with high- or low-executive demand. The mean average effect of LLD was calculated and compared to the incremental effect of aMCI or AD on the scores. Linear regressions including education, age, and severity and type of depression were run to seek their power of prediction for the mean average effects.

RESULTS

LLD has a medium effect on scores at semantic and phonemic fluency and naming and a small average effect on the low-executive demand tasks. Differences in education is a predictor of the effect of LLD on phonemic fluency and naming but not on semantic fluency or on low-executive demand tasks. Except for semantic fluency, aMCI did not demonstrate an incremental effect on the scores compared to LLD, while AD did, for all the tasks except phonemic fluency.

CONCLUSION

Assessment of semantic memory can be a discriminating clue for the distinction between depression and Alzheimer's disease but some methodological variables are highly influential to the scores, especially education. However, high-executive semantic tasks alone do not allow us to clearly distinguish LLD from AD or aMCI, as both pathologies seem to have a largely dialectical influential relationship, but low-executive semantic tasks appear as more sensible to this pathological distinction.

Gendered racism and subjective cognitive complaints among older black women: The role of depression and coping

Objective: Psychosocial stress is a risk factor for cognitive impairment and a potential pathway through which disparities in cognitive functioning emerge and disproportionately disadvantage older Black adults. Gendered racism is a psychosocial stressor that has negative implications for Black women's mental and physical health. This study tested the association between lifetime experiences of gendered racism and subjective cognitive complaints, taking into account the extent to which depressive symptoms and coping styles may explain this association. Method: Data from 75 older Black women (M_age = 62.43, SD = 6.23 years) were collected using an online survey assessing lifetime experiences of gendered racism, depressive symptoms, coping styles (i.e. spirituality, social support, problem-oriented/engagement, and disengagement), and subjective cognitive complaints (i.e. memory, attention, executive functioning, language, and overall cognition). The association between gendered racism and subjective cognitive complaints was examined with simple linear regression. Two mediation models examined depressive symptoms and coping styles as independent mediators of this association. Results: More gendered racism across the lifetime was associated with more subjective cognitive complaints separately through depressive symptoms and disengagement coping, but no other coping styles. Conclusion: Gendered racism is linked to increased subjective cognitive complaints via depressive symptoms and disengagement coping. The study highlights the importance of taking into account lived experiences (gendered racism) that are inextricably linked to social positioning (race and gender) within neuropsychology. Results evidence the negative impact of psychosocial stress, specifically gendered racism, on older Black women's subjective cognitive functioning, and illuminate avenues for clinical intervention and social justice advocacy.

Cognitive compensatory mechanisms in normal aging: a study on verbal fluency and the contribution of other cognitive functions

Verbal fluency has been widely studied in cognitive aging. However, compensatory mechanisms that maintain its optimal performance with increasing age are not completely understood. Using cross-sectional data, we investigated differentiation and dedifferentiation processes in verbal fluency across the lifespan by analyzing the association between verbal fluency and numerous cognitive measures within four age groups (N=446): early middle-age (32-45 years), late middle-age (46-58 years), early elderly (59-71 years), and late elderly (72-84 years). ANCOVA was used to investigate the interaction between age and fluency modality. Random forest models were conducted to study the contribution of cognition to semantic, phonemic, and action fluency. All modalities declined with increasing age, but semantic fluency was the most vulnerable to aging. The most prominent reduction in performance was observed during the transition from middle-age to early elderly, when cognitive variables stopped contributing (differentiation), and new cognitive variables started contributing (dedifferentiation). Lexical access, processing speed, and executive functions were among the most contributing functions. We conclude that the association between age and verbal fluency is masked by age-specific influences of other cognitive functions. Differentiation and dedifferentiation processes can coexist. This study provides important data for better understanding of cognitive aging and compensatory processes.

Verbal fluency in a national sample: Telephone administration methods

OBJECTIVES

Describe novel methods for ascertaining verbal fluency in a large national sample of adults, examine demographic factors influencing performance, and compare scores to studies using in-person assessment.

METHODS/DESIGN

Participants were from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a national, population-based, longitudinal study of stroke in adults aged 45 years and older. Letter and semantic fluency were gathered, using Letter "F" and Animal Naming, via a telephone-based assessment with computer-assisted scoring of digital recordings.

RESULTS

Initial letter and semantic fluency scores were obtained on 18 505 and 18 072 participants, respectively. For both fluency tests, scores were normally distributed. Younger age and more years of education were associated with better performances (p < 0.0001). The mean and standard deviation for matched subgroups, based on age, gender, and education, were quite comparable with scores reported out of samples using an in-person administration format. Telephone-based assessment also allowed for a level of quality control not available via in-person measurement.

CONCLUSIONS

Telephone-based assessment of verbal fluency and computer-assisted scoring programs designed for this study facilitated large-scale data acquisition, storage, and scoring of protocols. The resulting scores have similar characteristics to those obtained by traditional methods. These findings extend validation of cognitive assessment methods, using survey research staff and computer-assisted technology for test administration.

Language Patterns Discriminate Mild Depression From Normal Sadness and Euthymic State

OBJECTIVES

Deviations from typical word use have been previously reported in clinical depression, but language patterns of mild depression (MD), as distinct from normal sadness (NS) and euthymic state, are unknown. In this study, we aimed to apply the linguistic approach as an additional diagnostic key for understanding clinical variability along the continuum of affective states.

METHODS

We studied 402 written reports from 124 Russian-speaking patients and 77 healthy controls (HC), including 35 cases of NS, using hand-coding procedures. The focus of our psycholinguistic methods was on lexico-semantic [e.g., rhetorical figures (metaphors, similes)], syntactic [e.g., predominant sentence type (single-clause and multi-clause)], and lexico-grammatical [e.g., pronouns (indefinite, personal)] variables. Statistical evaluations included Cohen's kappa for inter-rater reliability measures, a non-parametric approach (Mann-Whitney U-test and Pearson chi-square test), one-way ANOVA for between-group differences, Spearman's and point-biserial correlations to analyze relationships between linguistic and gender variables, discriminant analysis (Wilks' λ) of linguistic variables in relation to the affective diagnostic types, all using SPSS-22 (significant, p < 0.05).

RESULTS

In MD, as compared with healthy individuals, written responses were longer, demonstrated descriptive rather than analytic style, showed signs of spoken and figurative language, single-clause sentences domination over multi-clause, atypical word order, increased use of personal and indefinite pronouns, and verb use in continuous/imperfective and past tenses. In NS, as compared with HC, we found greater use of lexical repetitions, omission of words, and verbs in continuous and present tenses. MD was significantly differentiated from NS and euthymic state by linguistic variables [98.6%; Wilks' λ(40) = 0.009; p < 0.001; r = 0.992]. The highest predictors in discrimination between MD, NS, and euthymic state groups were the variables of word order (typical/atypical) (r = -0.405), ellipses (omission of words) (r = 0.583), colloquialisms (informal words/phrases) (r = 0.534), verb tense (past/present/future) (r = -0.460), verbs form (continuous/perfect) (r = 0.345), amount of reflexive (e.g., myself)/personal (r = 0.344), and negative (e.g., nobody)/indefinite (r = 0.451) pronouns. The most significant between-group differences were observed in MD as compared with both NS and euthymic state.

CONCLUSION

MD is characterized by patterns of atypical language use distinguishing depression from NS and euthymic state, which points to a potential role of linguistic indicators in diagnosing affective states.

Verbal fluency tests: Normative data for the Latin American Spanish speaking adult population

OBJECTIVE

To generate normative data for the Verbal Fluency Tests across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate.

METHOD

The sample consisted of 3,977 healthy adults who were recruited from Argentina, Bolivia, Chile, Cuba, El Salvador, Guatemala, Honduras, Mexico, Paraguay, Peru, and, Puerto Rico. Each subject was administered the Verbal Fluency Test as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms.

RESULTS

The final multiple linear regression models for the letter F explained 8-30% of the variance, 7-32% for letter A, 8-32% for the letter S, and 16-43% for the animal category in Verbal Fluency Test scores. Although t-tests showed significant differences between men and women on the Verbal Fluency Test, they did not have an effect size larger than 0.3. As a result, gender-adjusted norms were not generated.

CONCLUSIONS

This is the first normative multicenter study conducted in Latin America aiming to create norms for the Verbal Fluency Test; this study will have important outcomes for the future of neuropsychology in the region.

Normative Data for the Cognitively Intact Oldest-Old: The Framingham Heart Study

BACKGROUND/STUDY CONTEXT: The number of individuals who reach extreme age is quickly increasing. Much of the current literature focuses on impaired cognition in extreme age, and debate continues regarding what constitutes "normal" cognition in extreme age. This study aimed to provide oldest-old normative data and to compare cognitive performances of cognitively intact elderly individuals from the Framingham Heart Study.

METHODS

A total of 1302 individuals aged 65+ years from the Framingham Heart Study were separated into 5-year age bands and compared on cognitive tests. Multivariate linear regression analyses were conducted, adjusting for gender, the Wide Range Achievement Test-Third Edition (WRAT-III) Reading score, and cohort. Analyses also included comparisons between 418 individuals aged 80+ and 884 individuals aged 65-79, and comparisons within oldest-old age bands.

RESULTS

Normative data for all participants are presented. Significant differences were found on most tests between age groups in the overall analysis between young-old and oldest-old, and analysis of oldest-old age bands also revealed select significant differences (all ps <.05).

CONCLUSION

As aging increases, significant cognitive differences and increased variability in performances are evident. These results support the use of age-appropriate normative data for oldest-old individuals.

Systematic review of neurocognition in people with co-occurring alcohol misuse and depression

BACKGROUND

Alcohol misuse and depression represent two major social and health problems globally. These conditions commonly co-occur and both are associated with significant cognitive impairment. Despite this, few studies have examined the impact on cognitive functioning of co-occurring alcohol misuse and depression. This study aims to critically review findings from peer-reviewed published articles examining neuropsychological test performance among samples of people with co-occurring alcohol misuse and depression.

METHOD

A comprehensive literature search was conducted, yielding six studies reporting neuropsychological profiles of people with co-occurring alcohol misuse and depression. Results comparing cognitive functioning of people with this comorbidity to those with alcohol misuse alone, depression alone, healthy controls and published norms were examined as well as those describing the correlation between depressive symptoms and cognitive functioning in people with alcohol use disorders.

RESULTS

In the majority of instances, the comorbid groups did not differ significantly from those with depression only or alcohol misuse only, nor from healthy controls or published norms. In the cases where a difference in neuropsychological test scores between groups was found, it was not consistently identified across studies. However, visual memory was identified in two studies as being impaired in comorbid samples and is worthy of inclusion in future studies.

LIMITATIONS

Due to the small number of included studies and the large variation in inclusion criteria as well as differing assessment tools and methodologies between studies, the review did not include a quantitative synthesis.

CONCLUSIONS

Research into cognitive deficits among people with singly occurring versus co-occurring alcohol misuse and depression is accumulating. Evidence suggests that the neuropsychological performance among samples with this comorbidity is generally not severely impaired and is unlikely to preclude benefit from treatment.

Differential diagnosis of depression and Alzheimer's disease with the Addenbrooke's Cognitive Examination-Revised (ACE-R)

Background

One of the usual problems psychologists and clinicians face in clinical practice is differential diagnostics of Alzheimer’s disease and depression. It has been reported that the ACE and ACE-R could discriminate the cognitive dysfunctions due to depression from that due to dementia, although this is not uniform in all studies. The current study aimed to evaluate the utility of the ACE-R to differentiate late-life onset depression (with severe episode) from mild-moderate Alzheimer’s Disease (AD).

Methods

This study received approval from the Lithuanian Bioethics Committee. All participants were older than 50 years (mean age = 66.52 (±8.76) years). The study sample consisted of 295 individuals: 117 with severe depression, 85 with mild-moderate Alzheimer’s disease (AD), and 94 age, gender and education matched participants of control group.

Results

The ACE-R had high sensitivity (100%) and specificity (81%) at detecting cognitive impairments related to AD. Patients with late-life onset depression (ACE-R mean 76.82, SD = 7.36) performed worse than controls (ACE-R mean 85.08, SD = 7.2), but better than the AD group (ACE-R mean 54.74, SD = 12.19). Participants with late-life onset depression were differentiated by mild impairment in the ACE-R total score with mild memory (13.79, SD = 6.29) and greater deficits in letter fluency (3.65, SD = 1.21) than in semantic fluency (4.68, SD = 1.23). Participants with AD were differentiated by severely impaired performance on attention and orientation (11.80, SD = 2.93), memory (8.25, SD = 3.47) and language subtests (17.21, SD = 4.04), and moderately impaired performance on verbal fluency (6.07, SD = 2.74).

Conclusions

ACE-R has diagnostic accuracy in detecting people with AD and can be used in differential diagnostics of late-life onset depression (severe episode) and AD. Diagnostic accuracy may be improved by analyzing the neuropsychological profiles and using lower cutoffs for different age groups.

Cognitive performance is impaired in coeliac patients on gluten free diet: a case-control study in patients older than 65 years of age

INTRODUCTION

Retrospective studies and case reports suggest an association between coeliac disease and impaired cognitive function.

AIM

To evaluate functional and cognitive performances in coeliac disease vs. control patients older than 65 years.

METHOD

Eighteen coeliac disease patients (75±4 years, group A) on gluten free diet since 5.5±3 years and 18 age-sex matched controls (76±4 years, group B) were studied using a battery of neuropsychological tests. Results of functional and cognitive tests are expressed as "row scores" and as "equivalent scores" by relating "raw scores" to reference rank categories.

RESULTS

Barthel Index of functional performance was similar in the 2 groups. "Raw score" was significantly lower in coeliac disease than controls for Mini Mental Test Examination (p=0.02), Trail Making Test (p=0.001), Semantic Fluency (p=0.03), Digit Symbol Test (p=0.007), Ideo-motor apraxia (p<0.001) and Bucco-facial apraxia (p<0.002). "Equivalent score" was also lower in coeliac disease than controls for Semantic memory (p<0.01) and for Ideo-motor apraxia (p=0.007).

CONCLUSION

Cognitive performance is worse in elderly coeliac disease than control patients, despite prolonged gluten avoidance in coeliacs. Awareness on the increasing phenomenon of late-onset coeliac disease is important to minimize diagnostic delay and prolonged exposure to gluten that may adversely and irreversibly affect cognitive function.

Prevalence of health conditions and predictors of mortality in oldest old Mexican Americans and non-Hispanic whites

BACKGROUND

The oldest old represent a unique group of older adults. This group is rapidly growing worldwide and yet there are gaps in the knowledge related to their health condition. Ethnic differences in disease prevalence and mortality must be understood to better care for the oldest old.

OBJECTIVE

To compare prevalence of common health conditions and predictors of mortality in oldest old Mexican Americans and non-Hispanic whites.

METHODS

This study included 568 community-dwelling Mexican Americans (MA) aged 85 years and older from the Hispanic Established Population for the Epidemiological Study of the Elderly 2004-2005 and 933 non-Hispanic whites (NHW) of the same age from the Health and Retirement Study 2004. Measures included sociodemographic variables, self-reported medical conditions, activities of daily living (ADLs), and instrumental activities of daily living. Logistic regression analysis was used to examine 2-year mortality in both populations.

RESULTS

Heart attack was significantly more prevalent in oldest old NHW compared with MA, regardless of gender. Conversely, diabetes was significantly more prevalent among MA men and women compared with their NHW counterparts. Compared with NHW men, MA men had significantly higher prevalence of cognitive impairment and hypertension. Additionally, prevalence of hip fracture was significantly higher for MA women compared with NHW women. Significant differences in ADL disability were observed only between both groups of women, whereas significant differences in instrumental activities of daily living disability were observed only between men. MA men and women had higher prevalence of obesity compared with NHW. Predictors of 2-year mortality for both ethnic groups included older age, male gender, and ADL disability. Cognitive impairment was a mortality predictor only for NHW. Similarly, lung disease was a predictor only for MA.

CONCLUSION

Health-related conditions that affect the oldest old vary by gender and ethnicity and entail careful evaluation and monitoring in the clinical setting. Better care requires inclusion of such differences as part of the comprehensive evaluation of the oldest old adults.

Regulation of affect in late adulthood: effects of mild depressive symptoms

BACKGROUND

Recent research has highlighted the important role of emotion dysregulation in the occurrence and maintenance of depressive symptomatology.

OBJECTIVES

The purpose of this study was to test the effects of mild depressive symptoms (MDS) on older adults' ability to regulate emotional experiences.

METHOD

A total of 70 community dwelling older adults completed self-report measures of affect and were asked to report how often they use specific emotion regulation strategies.

RESULTS

Consistent with previous theories older adults experiencing MDS reported greater difficulties in regulating affect compared to normal controls (NCs).

CONCLUSION

The present results provide support for previous findings demonstrating that experiencing depressive symptoms affects the ability to regulate emotional responses. Current findings are likely to be informative in terms of understanding emotion dysregulation in older adults at risk of experiencing clinical symptoms of depression.

The utility and benefits of clinical neuropsychology in Asia

Neuropsychological evaluation is the clinical practice of identifying and measuring impairments in mental functions in the context of a patient's mental strengths and preserved abilities for the purposes of diagnosis, rehabilitation planning, and long-term care. Best practice approaches to the medical management of neurodegenerative, neurological and psychiatric illness have lead to increasing demand for neuropsychological services. The simultaneous challenges of Asias' increasing adult and rapidly ageing population underscore the need for consideration of the role of neuropsychological services in day-to-day clinical practice. Here, we outline the clinical utility of neuropsychological assessment and indications for its use in general psychiatric practice.

Frontal Atrophy and Attention Deficits in Older Adults with a History of Elevated Depressive Symptoms

Studies of older adults with depressive disorders indicate greater cognitive deficits and brain alterations than would be expected for their age. There is some evidence that these findings are present after a single episode of depression, but this work has been cross-sectional in nature. We investigated both cross-sectional and longitudinal associations between a history of elevated depressive symptoms (HDS), frontal lobe volumes, and cognitive performance within the context of normal age-related changes over time in the Baltimore Longitudinal Study of Aging. After controlling for age, HDS was associated with smaller total frontal gray matter volumes and with smaller regional volumes in the cingulate gyrus and orbitofrontal cortex. Men, but not women, with HDS showed deficits in auditory attention span at older ages. Results confirm previous reports that even a single episode of depression is associated with adverse outcomes in older adults but suggest that HDS does not affect longitudinal trajectories of cognitive and brain volume change.

Neurocognitive profiles of people with comorbid depression and alcohol use: implications for psychological interventions

Depression and alcohol use disorders frequently co-occur and are highly prevalent. Both conditions are known to impair cognitive functioning, yet research into the role of these impairments in response to Cognitive Behaviour Therapy (CBT) is limited. The purpose of the present study was to examine the relationship between baseline neuropsychological performance, severity of depressive symptoms and alcohol use disorders. Participants with current depression and hazardous alcohol use were functioning in the average range on all neuropsychological measures prior to treatment entry. Baseline measures of drinking severity and a range of cognitive functions were inversely correlated. After controlling for other baseline variables, superior baseline cognitive functioning predicted greater reductions in depression severity after 17 weeks. These predictive effects occurred across both brief and extended interventions. Findings suggest that improvement in depression following psychological treatment is enhanced by greater fluid reasoning ability and is predicted by executive functioning, regardless of the treatment length or problem focus.

Longitudinal study of chronic depressive symptoms and regional cerebral blood flow in older men and women

OBJECTIVES

Late-life depression is associated with alterations in regional cerebral blood flow (rCBF) and metabolism in a neural network that includes frontostriatal and limbic regions and the cerebellum. Prior studies suggest that clinical depression and subthreshold depressive symptoms (SDS) are associated with similar cognitive deficits and structural brain changes, but little is known about the relationship between SDS and patterns of brain activity. Additionally, the neural correlates of depression have not been fully explored in men and women separately. This study investigated cross-sectional and longitudinal relationships between SDS and rCBF in older men and women.

METHODS

Sixty-one dementia-free older adults (35 men, 26 women), 56 years of age and older at baseline, from the neuroimaging substudy of the Baltimore Longitudinal Study of Aging participated. Participants underwent resting-state PET scans at baseline and at year 9 and completed the Center for Epidemiologic Studies Depression Scale annually.

RESULTS

At 8-year follow-up, both men and women showed cross-sectional associations between mean depressive symptom scores and activity in primarily frontal and temporal regions and the cerebellum. Higher average depressive symptoms were associated with longitudinal rCBF decreases in frontal regions in both men and women, and in temporal regions in men.

CONCLUSION

Regions showing associations between activity and SDS were similar to those found in studies of clinical depression, providing support for the hypothesis that depressive syndromes exist on a continuum of severity. Sex differences in associations provide some evidence that the pathophysiology of depressive disorders differs between men and women.

Lexical and semantic fluency discrepancy scores in aMCI and early Alzheimer's disease

Episodic memory is compromised in amnestic mild cognitive impairment (aMCI), but lesser deficits in other cognitive domains are also commonly observed and may be helpful in identifying this group. The relative difference in performance on lexical and semantic fluency tasks may be a sensitive and specific measure in aMCI and early Alzheimer's disease (AD). We compared four groups of participants, 35 early AD, 47 aMCI, 24 healthy controls, and 18 depressive out-patient controls, on semantic and lexical fluency as well as other neuropsychological tests. Early AD and aMCI patients showed a distinct pattern of semantic impairment in the two fluency measures compared with the healthy and depressive controls. The findings implicate early failure of the semantic memory system in aMCI and AD and suggest that consideration of the discrepancy in performance on semantic and lexical fluency measures may help in the early identification of AD.

Language performance in Alzheimer's disease and mild cognitive impairment: a comparative review

Mild cognitive impairment (MCI) manifests as memory impairment in the absence of dementia and progresses to Alzheimer's disease (AD) at a rate of around 15% per annum, versus 1-2% in the general population. It thus constitutes a primary target for investigation of early markers of AD. Language deficits occur early in AD, and performance on verbal tasks is an important diagnostic criterion for both AD and MCI. We review language performance in MCI, compare these findings to those seen in AD, and identify the primary issues in understanding language performance in MCI and selecting tasks with diagnostic and prognostic value.

Differential association of concurrent, baseline, and average depressive symptoms with cognitive decline in older adults

OBJECTIVES

The impact of depressive symptoms on cognitive decline in older adults remains unclear due to inconsistent findings in the literature. It is also unclear whether effects of depressive symptoms on cognitive decline vary with age. This study investigated the effect of concurrent, baseline, and average depressive symptoms on cognitive functioning and decline, and examined the interactive effect of age and depressive symptoms on cognition.

DESIGN

Prospective observational design with examination of cognitive performance and depressive symptoms at 1- to 2-year intervals for up to 26 years.

SETTING

Baltimore Longitudinal Study of Aging, National Institute on Aging.

PARTICIPANTS

One thousand five hundred eighty-six dementia-free adults 50 years of age and older.

MEASUREMENTS

Scores over time on the Center for Epidemiologic Studies Depression Scale and measures of learning and memory, attention and executive functions, verbal and language abilities, visuospatial functioning, and general cognitive status.

RESULTS

Increased depressive symptoms were associated with poor cognitive functioning and cognitive decline in multiple domains. Concurrent, baseline, and average depressive symptoms had differential associations with cognition. Average depressive symptoms, a measure of chronic symptoms, seemed to show the most widespread effects on cognitive abilities. Effects of depressive symptoms on some frontal functions were greater with advancing age.

CONCLUSION

Depressive symptoms are associated with poor cognitive functioning and cognitive decline, particularly with advancing age. The widespread impact of average depressive symptoms on cognition suggests that clinicians should consider the chronicity of depressive symptoms when evaluating cognitive functioning in older adults.

The cognitive neuropsychology of depression in the elderly

BACKGROUND

The cognitive impairment of older depressed patients with late- as opposed to early-onset illness may show important differences, in that patients with early onset may suffer predominantly from impaired episodic memory, and those with late onset mainly from reductions of executive function and processing speed.

METHOD

We searched Medline and EMBASE as well as individual papers' reference lists for relevant publications, recording comparisons in neuropsychological test results between early-onset depression (EOD), late-onset depression (LOD) and healthy volunteers. Effect sizes are presented for cognitive domains, such as executive function, processing speed, episodic memory, semantic memory and mental state examination.

RESULTS

Patients with LOD showed greater reductions in processing speed and executive function than patients with EOD and controls. Both patient groups showed reduced function in all domains, except mental state, compared with controls.

CONCLUSION

Pronounced executive deficits are typical of the late-onset patients described in published studies, while episodic memory impairment is not specific to early-onset illness. Possible reasons and confounders are discussed.

A Temporal Lobe Factor in Verb Fluency

Verb fluency requires self-sustained verb retrieval. The brain correlates of this task are virtually unknown. We investigated the relations between verb and noun (semantic) fluency and regional brain perfusion in subjects with varying degrees of cognitive decline, ranging from very mild subjective impairment to Alzheimer's disease (AD). Data consisted of single-photon emission computed tomography (SPECT) data and temporally resolved verb and noun fluency scores from 93 participants. Impaired verb fluency was predicted by a temporal lobe hypoperfusion factor and low education, whereas high age and low perfusion in the parietotemporal-occipital region predicted impaired noun fluency. Analysis of perfusion within the temporal region indicated primary involvement of the temporal pole and medial temporal lobe in AD. This might reflect pathology of the anterior parahippocampal region, which appears early in neurodegenerative disease. Although temporal lobe structures have not usually been implicated in verb processing, early temporal pathology thus appears to contribute to impaired verb fluency in cognitive decline.

Reduced semantic fluency as an additional screening tool for subjects with questionable dementia

BACKGROUND

Subjective memory complaints in subjects with mild cognitive impairment may represent a genuine decline in episodic memory. This paper evaluates the neuropsychological correlates of the semantic fluency test in subjects with questionable dementia (QD).

METHODS

A total of 331 Chinese subjects (118 normal controls, NC, 150 with QD and 63 with mild Alzheimer's disease, AD) were assessed with the Category Verbal Fluency Test (CVFT), the AD Assessment Scale-cognitive subscale (ADAS-Cog), and digit and verbal span tests. CVFT performance was evaluated in each Clinical Dementia Rating (CDR) group. The total number of exemplars, the subcategory and the category size generated were evaluated. Neuropsychological correlates of CVFT scores were computed.

RESULTS

Significant differences in CVFT performance were found between the different CDR groups. The subjects with QD had intermediate scores compared to the NC and AD subjects (1-way ANOVA, p < 0.001, post-hoc Bonferroni comparisons). In NC the CVFT scores were significantly associated with ADAS-Cog total, and immediate and delayed recall scores (partial correlations controlled for age and education, p < 0.005). In the QD group the CVFT scores were correlated with ADAS-Cog total, and immediate recall and object naming scores (partial correlation controlled for age and education, p < 0.005). Regression analysis revealed that age and delayed recall were significant predictors of CVFT performance in NCs. In the QD group, age, ADAS-Cog immediate recall and object naming scores predicted the CVFT performance.

CONCLUSIONS

The CVFT was impaired in the subjects with QD. Apart from episodic memory, semantic memory deficits also occur early in AD. The different cognitive predictors of CVFT scores in the NC and QD groups suggest that the test is associated with specific psychological functions at different stages of cognitive impairment.

Estradiol and tryptophan depletion interact to modulate cognition in menopausal women

Despite an abundance of data in animals, there is little research in humans regarding how estrogen and serotonin (5-HT) may interact to influence cognition. Through the use of estrogen treatment (ET) and tryptophan depletion (TRP-D) in a within-subject design involving healthy menopausal women, we have manipulated both estrogen and 5-HT in order to evaluate their individual and joint effects. Although neither manipulation influenced visuospatial learning, a significant interaction suggested that estrogen exerted a protective effect on verbal memory, such that TRP-D impaired performance to a greater extent before the administration of ET. In consonance with this finding, ET was associated with a small, but positive mood effect on the day following active TRP-D. In addition, ET significantly improved letter-cued verbal fluency with and without TRP-D. Finally, time since last menstrual period was significantly associated with verbal memory scores, such that longer length of hypogonadism resulted in decreased verbal memory performance. These data support the interaction of estrogen and 5-HT in nonreproductive behavior in humans as well as highlight the role of ovarian steroids in cognition.

Diurnal cycle of salivary cortisol in older adult men and women with subjective complaints of memory deficits and/or depressive symptoms: relation to cognitive functioning

In populations of young and older adults, it has been shown that individuals may be categorized into one of three diurnal subgroups when salivary cortisol levels are assessed over a 2-day period and compared for their consistency across days: a typical subgroup, a flat subgroup, and an inconsistent subgroup. Interestingly, recent studies have reported that the typical subgroup represents the majority of the young and older adult population, a finding that is difficult to reconcile with previous studies showing increased cortisol levels in older adults with depression or cognitive impairments. In order to assess whether a typical diurnal cortisol profile is representative across different subgroups of older adults, we assessed diurnal cortisol cycle representation in a sample of older adults with subjective complaints of depression and/or memory problems. Furthermore, given the robust relationship between cortisol and cognitive function, the present study examined the association between the three diurnal subgroups and cognitive performance. Forty-two older individuals were recruited on the basis of reporting subjective complaints of either memory problems and/or depressive mood. Participants were asked to sample their saliva over a 2-day period and were then asked to undergo a neuropsychological evaluation that taps into short-term memory, declarative memory and language. The results showed that 69% of the sample presented a Flat cycle of salivary cortisol over a 2-day period while 19% presented an inconsistent pattern and 12% presented a typical pattern. Participants in the flat subgroup were significantly impaired on letter verbal fluency. Furthermore, a relationship was found between diurnal cortisol subgroup representation and subjective complaint profile. These findings show that older adults with complaints of memory problems and/or depressive symptoms do not present the typical profile of the diurnal cortisol cycle, and they provide a preliminary view of how diurnal cortisol profile relates to cognitive function during human aging.

Cerebral oxygenation changes in the prefrontal cortex: Effects of age and gender

Multi-channel near-infrared spectroscopy (NIRS) is an optical method, which allows non-invasive in vivo measurements of changes in the concentration of oxygenated (O(2)Hb) and deoxygenated (HHb) hemoglobin in living brain tissue, simultaneously from multiple measurement points. In the present study, 44 young and 42 elderly subjects were investigated by means of multi-channel NIRS (optical topography) during performance of the verbal fluency task (VFT). The aim of the study was to analyze the effects of the subjects' age and gender on functional brain activation during this cognitive task. In summary, the results clearly show that the VFT activated the left and right dorsolateral prefrontal cortex (increases in O(2)Hb and more localized decreases in HHb), with an obvious left-hemispheric dominance. The elderly subjects generally exhibited less activation and no left hemispheric lateralization effect. In contrast to a previous study, we did not find a clear influence of the subjects' gender on the brain activation pattern.