Episodic remembering in a population-based sample of nonagenarians: does major depression exacerbate the memory deficits seen in Alzheimer's disease?

Negative affect predicts subsequent cognitive change in multiple sclerosis

Baseline predictors of cognitive change were explored in a sample of persons with multiple sclerosis (MS). Potential predictors included demographic features, baseline clinical characteristics, and psychological state. Participants were 38 individuals diagnosed with either relapsing remitting or secondary progressive MS who did not meet criteria for a current major depressive episode. Subjects were tested at baseline and approximately 1 year in an ongoing longitudinal study of cognition in MS. Participants completed neuropsychological tests sensitive to impairment in MS. They also completed self-report measures of depression, anxiety, fatigue, apathy, and positive and negative affect. Baseline measures of negative affect (e.g., depressed mood, state anxiety, and negative affective state) consistently predicted cognitive change over the course of the study. Higher baseline levels of negative affect were associated with greater relative declines in cognitive performance. This longitudinal relation occurred in the absence of a cross-sectional relation between negative affect and overall cognition. High baseline negative affect particularly predicted a relative decline in episodic memory for newly learned verbal and visuospatial information. The negative affect measures were unique in their predictive value among all the baseline measures assessed. (JINS, 2009, 15, 53-61.).

Vitamin B status and cognitive performance in preclinical and clinical Alzheimer's disease: data from the Kungsholmen Project

BACKGROUND/AIMS

The impact of vitamin B status on cognitive functioning in Alzheimer's disease (AD) is disputed. Using a population-based sample, we examined the associations of vitamin B(12) and folate with cognitive functioning in clinical (n = 44) and preclinical (n = 39) AD.

METHODS

The groups were subdivided in terms of low (<200 pmol/l) versus normal levels of B(12) and low (<13 nmol/l) versus normal folate levels. Participants were administered tests of verbal and nonverbal episodic memory, visuospatial abilities and verbal fluency.

RESULTS

As expected, the preclinical AD group performed better than the AD group across most cognitive tests. More interestingly, the effects of low vitamin B(12) and folate levels were negligible across all cognitive tests in clinical and preclinical AD.

CONCLUSION

These findings suggest that the influence of vitamin B deficiency on cognitive functioning is overshadowed by the neurodegenerative processes associated with AD.

Cognitive deficits in preclinical Alzheimer's disease and vascular dementia: Patterns of findings from the Kungsholmen Project

Using data from the Kungsholmen Project (KP), we describe a program of research that focuses on preclinical cognitive markers of dementia. A large number of KP studies convincingly demonstrate that there is a preclinical period that spans several years in both Alzheimer's disease (AD) and vascular dementia (VaD), during which cognitive deficits are possible to detect. In AD, the preclinical impairment generalizes across a variety of cognitive domains, including episodic memory, executive functioning, perceptual speed, attention, verbal ability, and visuospatial skill. Although less research has been directed at cognition in preclinical VaD, the emerging evidence suggests a rather broad prodromal impairment in this disease as well. Thus, the nature of the cognitive impairment appears to be largely similar in preclinical AD and VaD. Despite the fact that average group differences in cognitive performance between incident dementia cases and controls are large several years before diagnosis, the distribution of scores in these groups overlap greatly. In order to improve group classification, future research should consider combining cognitive markers with preclinical indicators from other domains (e.g., biological, clinical, social, genetic) into multivariate prediction models.

Neuropsychological data in nondemented oldest old: the 90+ Study

Although the oldest old are the fastest growing segment of the population, little is known about their cognitive performance. Our aim was to compile a relatively brief test battery that could be completed by a majority of individuals aged 90 or over, compensates for sensory losses, and incorporates previously validated, standardized, and accessible instruments. Means, standard deviations, and percentiles for 10 neuropsychological tests covering multiple cognitive domains are reported for 339 nondemented members of the 90+ Study. Cognitive performance declined with age for two-thirds of the tests. Performance on some tests was also affected by gender, education, and depression scores.

Older adults in the SeniorWISE study at risk for mild cognitive impairment

As part of a larger clinical trial, SeniorWISE (Wisdom Is Simply Exploration), this study provides baseline affective, cognitive, and functional ability data and reports on the likely incidence of mild cognitive impairment (MCI) in a tri-ethnic community sample of older adults (N = 265). Seventy-eight individuals had memory complaints, whereas 105 had none. Of the complainants, 32 had normal memory function and 46 had poor memory performance. Among those without memory complaints, 42 had no memory impairment and 63 had poor memory performance. Forty-six individuals (17%) met the criteria of poor everyday memory functioning and memory complaints whereas 81 (31%) would be considered to be at risk based on other MCI criteria. This pattern of results suggests that those with declining memory are less aware of their deficits in activities of daily living that their actual performance would suggest are occurring.

Rate of cognitive decline in preclinical Alzheimer's disease: the role of comorbidity

We investigated the influence of individual-difference variables implicated as risk factors for Alzheimer's disease (AD) or known to be related to cognitive performance in normal aging (e.g., age, sex, years of education, previous and recent diseases, apolipoprotein E status, social network, and substance use) on rate of cognitive change from preclinical to clinical AD. With the use of data from a population-based study, 230 persons who were nondemented at baseline and diagnosed with AD at a 3-year follow-up were examined with the Mini-Mental State Examination (MMSE). Of all predictor variables examined, only number of diseases resulting in hospital admission during the follow-up period made an independent contribution to rate of MMSE change. These results suggest that many variables affecting the onset of the degenerative process as well as cognitive functioning in normal aging exert little influence on rate of cognitive change in preclinical AD. This may reflect the fact that the emerging dementia disease overshadows the role of these variables for cognitive functioning. A possible exception to this pattern is that an increasing number of concomitant health conditions may exacerbate the rate of cognitive decline during the final portion of the preclinical phase in AD.

Negligible effects of depression on verbal and spatial performance in Alzheimer's disease

We examined whether a diagnosis of depression affects verbal and visuospatial performance in Alzheimer's disease (AD). Using data from a population-based study, persons with AD and depression (AD/D), AD alone and a control group of normal older adults were compared in two tests of verbal ability (category and letter fluency) and two tests of visuospatial skill (block design and clock drawing). As expected, there were clear AD-related deficits across all cognitive tasks. More importantly, the AD and AD/D groups were indistinguishable on all task variables. The lack of effects of depression was discussed relative to the view that those symptoms of this disease which are especially detrimental to cognitive functioning (e.g. concentration difficulties, lack of interest, loss of energy) may already be present in AD as a result of the neurodegenerative process.

Further evidence on the effects of vitamin B12 and folate levels on episodic memory functioning: a population-based study of healthy very old adults

BACKGROUND

The relationship between vitamin status and cognitive functioning has been addressed in several recent studies with inconclusive results. The purpose of this study was to examine separate and combined effects of serum vitamin B12 and folic acid on episodic memory functioning in very old age.

METHODS

Four study groups were selected from a population-based sample of healthy very old adults (90-101 years of age): normal B12/normal folic acid, low B12/normal folic acid, normal B12/low folic acid, and low B12/low folic acid. Cutoff levels were set at 180 pmol/L for vitamin B12 and at 13 nmol/L for folic acid. Subjects completed two episodic recall tasks (objects and words) and two episodic recognition tasks (faces and words).

RESULTS

Neither vitamin affected recognition or primary memory. Most interesting, although B12 was unrelated to recall performance, subjects with low folic acid levels showed impairment in both word recall and object recall.

CONCLUSIONS

These results replicate and extend previous findings that folic acid may be more critical than B12 to memory functioning in late life. The selective effects of folic acid on episodic recall were discussed in terms of encoding and retrieval mechanisms, as well as in relation to brain protein synthesis.