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Biomedical subjects

B J Small

Publications and source records attributed to B J Small.

31 records · Page 2Linked to original sources

Preclinical symptoms of major depression in very old age: a prospective longitudinal study.

OBJECTIVE: The authors' goal was to examine whether individuals diagnosed as having major depression experienced greater levels of depressive symptoms and cognitive dysfunction up to 3 years before the clinical diagnosis was rendered. METHOD: The study included 185 subjects 75 years old or older who participated in a population-based longitudinal survey in Stockholm. Ten of the subjects were diagnosed as depressed up to 3 years after initial screening, and these individuals were compared with the 175 subjects who were not depressed at 3-year follow-up. Depression was diagnosed according to DSM-III-R and DSM-IV criteria. Psychiatric signs and symptoms were assessed by physicians using a structured interview. Cognitive functioning was assessed with the Mini-Mental State. RESULTS: At the initial screening, the patients later diagnosed as depressed had a greater number of depressive symptoms, such as dysphoria and appetite disturbance, and their symptoms were also more severe than those of the nondepressed subjects. Moreover, the depressed subjects suffered from a more severe lack of interest and psychomotor disturbance and had lower Mini-Mental State scores. CONCLUSIONS: There are preclinical markers for individuals who will become depressed after a 3-year interval. Major depression may have a more chronic nature in very old age, in contrast to the relatively short clinical onset of depression seen in younger adults. The authors conclude that standard diagnostic instruments such as DSM-IV may have to take this lengthy course of impairment into consideration when dealing with very old adults.

Adult↗

Detection of mild dementia in community surveys. Is it possible to increase the accuracy of our diagnostic instruments?

OBJECTIVE: To investigate the accuracy of cognitive tests and clinical dementia diagnosis in distinguishing between mildly demented and nondemented subjects. DESIGN: Three-year longitudinal follow-up of a community-based cohort sample. Using the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised as criterion variable, subjects were classified as demented and nondemented based on the results of cognitive test performance at time 1. These subjects were then examined prospectively for development of dementia at time 2. PARTICIPANTS: The sample consisted of 63 mildly demented (Mini-Mental State Examination score > 18 < 24) and 398 nondemented subjects at time 1. At follow-up, due to death and refusal of participation, the sample consisted of 108 demented and 217 nondemented subjects. RESULTS: The group of subjects who were considered to be demented according to the results of the cognitive tests and nondemented by the clinical diagnosis at time 1 had a higher incidence of dementia at time 2 than did the subjects who were considered to be nondemented according to both cognitive tests and clinical diagnosis. Among the incident dementia cases, subjects considered to be demented according to the cognitive tests but nondemented by the clinical diagnosis performed at a lower level on most cognitive tests were older, had less education, and consisted of more women than did the group of subjects who were considered to be demented by the clinical diagnosis and nondemented by the cognitive tests at time 1. CONCLUSIONS: A combination of cognitive tests, especially tasks assessing episodic memory, can detect many subjects in a preclinical state of dementia who could be missed in the clinical diagnostic procedure due to subjects' relatively high age, low education, and female sex. However, cognitive tests also may miss a sizable proportion of prevalent dementia cases due to possible insensitivity to the same demographic variables. These findings indicate the need of integration between clinical and cognitive data to increase the accuracy in detecting dementia in an early phase.

Aged↗

Cognitive correlates of mortality: evidence from a population-based sample of very old adults.

The authors examined performance on memory, visuospatial, and verbal tasks and subsequent mortality in adults 75-95 years. The sample consisted of 178 living and 44 deceased participants. Mean-level analyses revealed mortality group differences for all domains of cognitive functioning. A Cox regression analysis, independent of age, gender, education, functional ability, and chronic illness, indicated that measures of word recognition and category fluency were significant predictors of mortality status. The results indicate a relationship between cognitive performance and subsequent mortality status in very old age and suggest that episodic memory and verbal skill may be particularly sensitive in predicting such effects.

Aged↗

Cognitive predictors of incident Alzheimer's disease: a prospective longitudinal study.

The present study examined whether cognitive variables measured at baseline could predict incident cases of Alzheimer's disease (AD) after a 3-year follow-up period. Twenty-six incident AD adults and 179 very old (M = 83.5 years) adults without dementia participated in a population-based study. Cognitive performance was indexed by the Mini-Mental State Examination (MMSE) and multiple indices of memory and visuospatial and verbal performance. A logistic regression analysis that controlled for age, gender, and education indicated that MMSE scores were reliable indicators of who would develop AD. In addition, recall of organizable words, recognition of faces, and letter fluency were reliable predictors of subsequent dementia status after differences in MMSE performance were partialed out. Thus, although the MMSE is useful in predicting dementia, there is an additional advantage of assessing specific indices of cognitive functioning. Further, supportive episodic memory tasks may be more salient predictors of incident AD than tasks that offer less supportive encoding or retrieval conditions.

Aged↗

Cognitive changes in very old persons with dementia: the influence of demographic, psychometric, and biological variables.

Longitudinal changes in global cognitive functioning, indexed by the Mini-Mental State Examination (MMSE), in subjects with dementia (Alzheimer's disease and vascular dementia) were examined. The roles of several demographic, psychometric, and biological indices in predicting cognitive deterioration were also examined. The sample consisted of 36 very old (M age at entry = 83.0 years, range = 75-95) adults with dementia from a community-based study. Subjects were tested on two occasions separated by approximately 2.5 years. Results indicated significant longitudinal decline in MMSE scores over the retest interval; the average decline was estimated as 2.43 (SD = 1.81) points per year. Several factors were associated with cognitive deterioration. Higher initial MMSE scores were associated with greater deterioration, whereas superior forward digit span and Block Design at entry were associated with attenuated decline, once differences in baseline severity were accounted for. By contrast, a variety of other putatively important variables exhibited no relationship to decline, including age, gender, education, onset age, dementia type, backward digit span, as well as a number of biological parameters (e.g., vitamin B12, folic acid). The results suggest that although the magnitude of cognitive deterioration in dementia is highly variable, several indicators may be useful predictors of future changes in cognitive functioning.

Age of Onset↗

Mini-Mental State Examination item scores as predictors of Alzheimer's disease: incidence data from the Kungsholmen Project, Stockholm.

BACKGROUND: The present study examined the power of individual Mini-Mental State Examination (MMSE) items in predicting incidence of Alzheimer's disease (AD). In addition, 3-year longitudinal changes in MMSE items were contrasted between incident AD and nondemented persons. METHODS: A population-based group of very old adults, 75-95 years of age, were followed longitudinally. Of the original 327 participants, 32 were diagnosed with probable or possible AD after a 3-year follow-up interval and 189 remained nondemented. Cognitive performance was indexed by the individual item scores from the MMSE. These sample from multiple domains of cognitive functioning, including visuospatial skill, recent memory, orientation to time and place, language, and the ability to sustain attention. RESULTS: Items dealing with delayed episodic memory and orientation to time were significant predictors of AD incidence, independent of age, gender, and years of education, as determined by logistic regression analyses. Longitudinally, changes in performance were largest among individuals diagnosed as incident AD, although the magnitude of change across items was highly variable. In particular, decline was relatively small for the delayed memory item, whereas most other measures showed dramatic decline in performance among individuals with incident AD. CONCLUSIONS: Individual MMSE items, especially those with some type of episodic memory referent, were the best predictors of incident cases of AD. Moreover, MMSE items displayed differential rates of changes, particularly for the incident AD participants.

Aged↗

Adult age differences in perceptually based, but not conceptually based implicit tests of memory.

Implicit tests of memory assess the influence of recent experience without requiring awareness of remembering. Evidence concerning age differences on implicit tests of memory suggests small age differences in favor of younger adults. However, the majority of research examining this issue has relied upon perceptually based implicit tests. Recently, a second type of implicit test, one that relies upon conceptually based processes, has been identified. The pattern of age differences on this second type of implicit test is less clear. In the present study, we examined the pattern of age differences on one conceptually based (fact completion) and one perceptually based (stem completion) implicit test of memory, as well as two explicit tests of memory (fact and word recall). Tasks were administered to 403 adults from three age groups (19-34 years, 58-73 years, 74-89 years). Significant age differences in favor of the young were found on stem completion but not fact completion. Age differences were present for both word and fast recall. Correlational analyses examining the relationship of memory performance to other cognitive variables indicated that the implicit tests were supported by different components than the explicit tests, as well as being different from each other.

Adolescent↗

Age differences in cognitive performance in later life: relationships to self-reported health and activity life style.

The predictive relationships among individual differences in self-reported physical health and activity life style and performance on an array of information processing and intellectual ability measures were examined. A sample of 484 men and women aged 55 to 86 years completed a battery of cognitive tasks measuring verbal processing time, working memory, vocabulary, verbal fluency, world knowledge, word recall, and text recall. Hierarchical regression was used to predict performance on these tasks from measures of self-reported physical health, alcohol and tobacco use, and level of participation in everyday activities. The results indicated: (a) individual differences in self-reported health and activity predicted performance on multiple cognitive measures; (b) self-reported health was more predictive of processing resource variables than knowledge-based abilities; (c) interaction effects indicated that participation in cognitively demanding activities was more highly related to performance on some measures for older adults than for middle-aged adults; and (d) age-related differences in performance on multiple measures were attenuated by partialing individual differences in self-reported health and activity.

Activities of Daily Living↗

Short-term longitudinal change in cognitive performance in later life.

Changes in mean performance on memory, information processing, and intellectual ability tasks over a 3-year period were examined. The sample consisted of 328 community-dwelling men and women (from an original sample of 484 individuals) aged 55-86 years. Ss completed tasks yielding measures of verbal processing time, working memory, implicit memory, vocabulary, verbal fluency, world knowledge, reading comprehension, word recall, and text recall. The results showed significant average decline on working memory, verbal fluency, and world knowledge. There were also interactions for 2 processing time measures and working memory, showing greater decline in the earlier-born cohort group than in the later-born cohort group. A step-down analysis revealed that covarying declines in other variables, including processing time, did not eliminate significant declines in working memory, verbal fluency, and world knowledge.

Adult↗

Adult age differences in direct and indirect tests of memory.

Indirect tests of memory assess the influence of recent experience on task performance without requiring awareness of remembering. Evidence concerning whether there are reliable age differences on such indicators of implicit memory has been inconsistent. This inconsistency may be related either to the low power of previous studies, or the contamination of indirect measures by conscious memory retrieval strategies. In a statistically powerful test of this question, indirect and direct tests of memory were administered to 584 adults from three age groups (19-36 years, 55-69 years, 70-86 years). Significant age differences in favor of the young were found on the indirect test as well as direct tests, suggesting that there are small but reliable age differences in implicit memory. Correlational analyses examining the relationship of memory performance to other cognitive variables indicated that the indirect test was supported by different components than the direct tests.

Adult↗

Alpha-methyldopa interference with the phosphotungstate uric acid test.

The effect of alpha-methyldopa on the phosphotungstate method of uric acid analysis was tested using a group of 17 hypertensive patients being treated with only this drug for their elevated blood pressure. The uric acid values of these patients tested by the phosphotungstate method showed no significant difference from the uricase test values, when compared to a control population of 32 normotensive patients tested in the same manner. The proposed interference was further tested by in vitro studies. Both uricase and phosphotungstate analysis of uric acid was performed on serum containing various dilutions of alpha-methyldopa. The concentration of alpha-methyldopa required to clinically affect the uric acid level, whereby a false positive result occurred, was 60 mug/ml. The mean plasma aplha-methyldopa concentration in the study group, however, was found to be only 2.03 mug/ml. The postulated interference of therapeutic levels of alpha-methyldopa on the phosphotungstate uric acid method was invalid.

Adult↗

Predictors of longitudinal changes in memory, visuospatial, and verbal functioning in very old demented adults.

Longitudinal changes in memory, visuospatial and verbal functioning in a sample of demented persons were examined. The role of several demographic, psychometric, and biological indices in predicting the rate of cognitive deterioration was also investigated. The sample consisted of 31 very old (mean age at entry = 83.5 years, range = 75-95) persons with Alzheimer's disease (n = 22) and vascular dementia (n = 9) from a community-based study. Subjects were tested on two occasions separated by approximately 2.5 years. Results indicated significant longitudinal decline in verbal fluency and visuospatial ability, but only on 1 of 3 measures of episodic memory. Results from regression analyses indicated that a variety of putatively important variables, including age, gender, education, digit span, as well as a number of biological (vitamin B12, TSH), dementia etiology, and psychometric (digit span) indicators, exhibited no relationship to rate of memory, visuospatial, or verbal decline. The results suggest that the rate of cognitive deterioration in dementia is highly variable, and this variability in change appears to include a variety of characteristics. A possible reason thereof may be that the role of individual-difference variables for cognitive functioning in dementia is overshadowed by the pathogenetic process itself.

Aged↗