How clearly do we see our memories?

A Network Analysis of Depressive Symptoms in the Elderly with Subjective Memory Complaints

(1) Background: Subjective memory complaints (SMCs) are common among the elderly and are important because they can indicate early cognitive impairment. The factor with the greatest correlation with SMCs is depression. The purpose of this study is to examine depressive symptoms among elderly individuals with SMCs through a network analysis that can analyze disease models between symptoms; (2) Methods: A total of 3489 data collected from elderly individuals in the community were analyzed. The Subjective Memory Complaints Questionnaire and Patient Health Questionnaire-9 were evaluated. For statistical analysis, we investigated the features of the depressive symptoms network, including centrality and clustering; (3) Results: Network analysis of the SMC group showed strong associations in the order of Q1–Q2 (r = 0.499), Q7–Q8 (r = 0.330), and Q1–Q6 (r = 0.239). In terms of centrality index, Q2 was highest in strength and expected influence, followed by Q1 in all of betweenness, strength, and expected influence; (4) Conclusions: The network analysis confirmed that the most important factors in the subjective cognitive decline group were depressed mood and anhedonia, which also had a strong correlation in the network pattern.

Subjective memory complaint as a useful tool for the early detection of Alzheimer's disease

PURPOSE

Despite their high prevalence in Alzheimer's disease (AD), and the increasing level of concern they have generated, subjective memory complaints (SMCs) are poorly understood. This study investigated the accuracy with which SMC can separate mild cognitive impairment (MCI) and early AD from cognitive normal (CN), and explored whether the discrimination ability is similar to or better than that of the Mini-Mental State Exam (MMSE).

PATIENTS AND METHODS

This study recruited 175 CN subjects, 52 with MCI, and 66 with probable AD aged 60 years or older. To test the independent contributions of SMC and MMSE scores to the classification of cognitive status (CN vs MCI or early AD), logistic regression analyses were performed, adjusting for the following potential confounding variables: age, gender, Frontal Assessment Battery score, modified Hachinski Ischemic Scale score, and apolipoprotein E ε4 status. Receiver operating characteristic (ROC) curve analyses were used to determine the discrimination accuracy of SMC and MMSE scores, and area under the ROC curve (AUROC) was also calculated.

RESULTS

In the highly educated (≥7 years), nondepressed (Geriatric Depression Scale ≤15) subgroup, SMC showed good accuracy in discriminating cognitively impaired subjects from CN after adjusting for potential confounding variables (the AUROC of the adjusted SMC was 0.841 for MCI discrimination, and it was 0.858 for MCI plus early AD discrimination). Both SMC and MMSE scores significantly contributed to differentiating between CN and MCI (OR=2.372, 95% CI=1.086-5.177; OR=0.730, 95% CI=0.566-0.941, respectively) after adjusting for the same covariates. However, in the highly educated and nondepressed subgroups, SMC showed significant predictive power for MCI from CN (OR=3.119, 95% CI=1.190-8.176; OR=3.328, 95% CI=1.320-8.396, respectively), whereas MMSE scores did not.

CONCLUSION

Our findings support the usefulness of SMC, which was comparable or even superior to MMSE scores, for detecting MCI or early AD.

Objective and Subjective Cognitive Problems among Caregivers and Matched Non-caregivers

Purpose of the study

Caregivers (CGs) have been shown to do more poorly than non-caregivers (NCGs) on objective cognitive tests (Trails B and Digit Symbol Test, DST), but less is known about whether these groups differ in: (a) reports of subjective cognitive problems (SCPs, memory complaints, etc.) and (b) relationships of SCPs with objective cognitive tests, depression, and stress exposure. Such relationships are important because researchers/clinicians use SCPs as proxies for objective cognitive tests.

Design and methods

One hundred and twenty-two spouse CGs of persons with Alzheimer's disease and 117 demographically matched NCG spouses were compared on Trails B and DST at baseline (T1), 1 year later (T2), and 2 years later (T3) and on SCPs at T1.

Results

Trails B was slower in CGs than NCGs and DST declined in CGs relative to NCGs. CGs reported more SCPs than NCGs. Depression mediated group differences in Trails and DST and was also associated with SCPs. Trails B and DST explained variance in SCPs in NCGs, but not in CGs. Hours of care explained variance in SCPs in CGs, but not in NCGs.

Implications

When using SCPs to make inferences about CG cognitive function, researchers/clinicians should consider the possible influence of stress exposures and depression. The lack of associations of objective and subjective cognitive measures may be a reflection of poorer self-monitoring among CGs, a potential new area of CG research.

Prevalence and Cognitive Bases of Subjective Memory Complaints in Older Adults: Evidence from a Community Sample

Objectives. To estimate the prevalence of subjective memory complaints (SMCs) in a sample of community-dwelling, older adults and to examine cognitive bases of these complaints. Participants. 499 community-dwelling adults, 65 and older. Measurements. A telephone survey consisting of cognitive tests and clinical and sociodemographic variables. SMCs were based on subjects' evaluations and subjects' perceptions of others' evaluations. Analysis. Logistic regression was used to model the risk for SMCs as a function of the cognitive, clinical, and sociodemographic variables. We tested for interactions of the cognitive variables with age, education, and gender. Results. 27.1% reported memory complaints. Among the younger age, better objective memory performance predicted lower risk for SMCs, while among the older age, better memory had no effect on risk. Among the better-educated people, better global cognitive functioning predicted lower risk for SMCs, while among the less-educated people, better global cognitive functioning had no effect on SMC risk. When predicting others' perceptions, better objective memory was associated with lower risk for SMCs. Conclusion. Objective memory performance and global cognitive functioning are associated with lower risk for SMCs, but these relationships are the strongest for the younger age and those with more education, respectively. Age and education may affect the ability to accurately appraise cognitive functioning.

Autobiographical Recall Training in Elderly Adults with Subjective Memory Complaint: A Pilot Study

Subjective memory complaint is a self-reported memory impairment which affects elderly people. This problem does not interfere with daily living activities but could decrease quality of life. This study's purpose was to verify whether a specific, newly developed, autobiographical recall training could modify self-perception of memory of subjects with subjective memory complaint. Seven elderly subjects (4 women and 3 men; mean age 65.5 yr., SD = 11) with such complaint, evidenced through a specific questionnaire, attended the training course and were prospectively assessed on standard neuropsychological tests, depressive symptomatology, and self-perception of memory. Self-perception of memory, as assessed by scores on a formalized questionnaire, improved significantly after the training, while depressive symptoms did not change. Neuropsychological performances were normal before and after the training, but a statistically significant improvement was observed only on the phonological fluency test. Thus the present pilot study suggested that the training may be effective in improving self-perception of memory and metamnestic capacity in elderly people with subjective memory complaints but not in changing subjects' depressive symptoms. This requires replication of this work with a much larger sample so statistical power is adequate.

Subjective Cognitive Complaints and Cognitive Decline: Consequence or Predictor? The Epidemiology of Vascular Aging Study

OBJECTIVES

To explore whether more cognitive complaints are associated with previous or future cognitive decline.

DESIGN

Longitudinal; epidemiology vascular aging study.

SETTING

Community in Nantes, France.

PARTICIPANTS

Seven hundred thirty-three subjects, aged 59 to 71.

MEASUREMENTS

Subjective cognitive complaints were recorded at 4-year follow-up examination in a prospective study of people aged 59 to 71 at study entry. Participants' cognitive performances were assessed repeatedly at each wave (baseline, 4 years, and 6 years) of the study using a series of neuropsychological tests including the Mini-Mental State Examination. Depressive symptoms were evaluated using the Center for Epidemiological Studies Depression Scale. Subjects also had a cerebral magnetic resonance imaging scan at 4-year follow-up to evaluate presence and severity of white matter hyperintensities (WMHs).

RESULTS

Subjects with more cognitive complaints had greater cognitive decline. This significant relationship persisted after adjusting for potential confounders, including depressive symptoms. Multivariate analysis also showed that, in subjects without measured cognitive decline between study entry and 4-year follow-up, those with more cognitive complaints at 4-year follow-up had significantly greater measured cognitive decline during the subsequent 2 years. In the presence of severe WMH, more cognitive complaints were an even stronger predictor of future cognitive decline.

CONCLUSION

Cognitive complaints reflect measured cognitive decline, but they also predict cognitive decline at an earlier stage than objective tests that are not able to detect cognitive deficits. They need to be taken into account in clinical practice.

Subjective Memory Deterioration and Future Dementia in People Aged 65 and Older

OBJECTIVES

To study whether subjective memory deterioration is associated with future dementia in older people.

DESIGN

A population-based prospective cohort study begun in 1994 with biennial follow-up interviews.

SETTING

Community-based members of Group Health Cooperative, a large health maintenance organization in the Seattle area.

PARTICIPANTS

A sample of 1,883 subjects, dementia free, aged 65 and older, who scored 91 or higher on the 100-point Cognitive Ability Screening Instrument (CASI) at study entry.

MEASUREMENTS

Subjective memory was assessed by asking whether memory had changed on 5-point Likert scales (e.g., 1=definitely improved, 3=no change, 5=definitely deteriorated) with regard to five items: remembering names, faces, friends, and appointments and judging the time. The items were summed for a possible total score ranging from 5 to 25. Subjective memory deterioration was defined as present if the total score was 20 or above. Cognitive performance was measured using the CASI. Incident dementia cases were identified using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria.

RESULTS

Of 1,883 subjects, 126 developed dementia during 5 years of follow-up. Subjective memory deterioration was associated with cognitive decline and incident dementia. Age modified the association between subjective memory deterioration and future dementia. For persons reporting subjective memory deterioration at the ages of 70, 75, and 80, the hazard ratios of developing dementia were 6.0 (95% confidence interval (CI)=2.1-18), 3.2 (95% CI=1.6-6.2) and 1.6 (95% CI=0.86-3.1), respectively.

CONCLUSION

Subjective memory deterioration was found to precede the development of dementia in older people with normal cognitive screening results. These findings suggest that a high level of subjective memory deterioration in persons with normal objective cognitive function may identify a subset of individuals at greater risk for developing dementia.

Are memory complaints predictive for dementia? A review of clinical and population-based studies

OBJECTIVES

To review studies that have reported on the prevalence of memory complaints and the relationship between memory complaints and impairment or decline (dementia) in elderly individuals.

DATA SOURCES AND STUDY SELECTION

All publications in the English language relating to memory complaints, memory impairment, cognitive disorder and dementia in MEDLINE, PSYCHLIT and EMBASE computerized databases, together with a search of relevant citations.

DATA SYNTHESIS

The prevalence of memory complaints, defined as everyday memory problems, shows a large variation of approximately 25 - 50%. A high age, female gender and a low level of education are generally associated with a high prevalence of memory complaints. In community-based samples of elderly subjects an association has been found between memory complaints and memory impairment, after adjustment for depressive symptomatology. Memory complaints predict dementia after a follow-up of at least 2 years, in particular in those with mild cognitive impairment, defined as Mini Mental State Examination (MMSE) > 23. Memory complaints in highly educated elderly subjects may be predictive of dementia even when there is no indication of cognitive impairment on short cognitive screen tests. The shift in methodology which is noticeable in the recently published major studies is discussed as a possible explanation for the established association between memory complaints and decline in memory (or dementia) in elderly subjects. Three methodological factors, in particular, are responsible for the results: community-based sampling, longitudinal design and the treatment of variables such as depression, cognitive impairment and level of education.

CONCLUSION

Memory complaints in elderly people should no longer be considered merely as an innocent age-related phenomenon or a symptom of depression. Instead, these complaints deserve to be taken seriously, at least as a possible early sign of dementia.

Subjective memory complaints in the elderly: depressive symptoms and future dementia

BACKGROUND

Population studies indicate that subjective memory complaints by elderly people are correlated with cognitive performance. These complaints have some predictive power regarding the development of dementia. The present study attempted to replicate this finding, and investigated which variables determine subjective memory complaints.

METHOD

Participants in the Amsterdam Study of the Elderly (n = 2114; 65-84 years of age), who were not demented and had a normal MMSE score (> 23) at baseline, were re-examined after four years. Subjective complaints were measured using a previously developed scale. Dementia and depression were measured using the Geriatric Mental State Schedule (GMS). Premorbid intelligence was measured by the Dutch Adult Reading Test (DART).

RESULTS

Memory complaints at baseline contributed a small but significant amount of diagnostic information with respect to the prediction of future dementia. Depressive symptoms at baseline had no predictive value when these memory complaints were accounted for. Subjective memory complaints were associated with depression, baseline MMSE score, and premorbid intelligence.

CONCLUSIONS

Subjective memory complaints are not just secondary to depression, but in part reflect realistic self-observations of cognitive decline.