Coupled cognitive and functional change in Alzheimer's disease and the influence of depressive symptoms

The mediating effect of the amygdala-frontal circuit on the association between depressive symptoms and cognitive function in Alzheimer's disease

Depressive symptoms occur commonly in Alzheimer's disease (AD). Although abnormalities in the amygdala-frontal circuit have been linked to emotional dysregulation and cognitive impairment, the neurological basis underlying these associations in AD patients with depressive symptoms (ADD) is unclear. We aimed to investigate the relationship between the amygdala-frontal circuit and depressive symptoms and cognitive function in ADD. We recruited 60 ADD, 60 AD patients without depressive symptoms (ADND), and 60 healthy controls (HC). Functional connectivity (FC) maps of the bilateral amygdala were compared. Fractional anisotropy (FA) of the amygdala-frontal circuit connected by the uncinate fasciculus (UF) was calculated using automated fiber quantification (AFQ). In addition, mediation analysis was performed to explore the effects of the amygdala-frontal circuit on the relationship between depressive symptoms and cognitive function. We found decreased bilateral amygdala FC with the inferior frontal gyrus (IFG) in the ADD group compared to the ADND and HC groups. Moreover, FA in the left frontal UF (nodes 64-97) was significantly lower in the ADD group than ADND group. Notably, amygdala-based FC with IFG and the left frontal UF FA mediated the relationship between depressive symptoms and cognitive function in ADD, with mediating effects ranging between 15 and 18%. Our study is the first to demonstrate the mediating effect of functional and microstructural abnormalities in the amygdala-frontal circuit in ADD. The findings suggest that the amygdala-frontal circuit may underlie emotional dysregulation in ADD, providing potential targets for treatment strategies.

The treatment of behavioural and psychological symptoms in dementia: pragmatic recommendations

Behavioural and psychological symptoms of dementia (BPSD) are a clinical challenge for the lack of a sound taxonomy, frequent presentation with comorbid BPSD, lack of specific pharmacologic interventions, poor base of methodologically sound evidence with randomized clinical trials, contamination from the treatment of behavioural disturbances of young and adult psychiatric conditions, and small efficacy window of psychotropic drugs. We present here a treatment workflow based on a concept-driven literature review based on the notions that (i) the aetiology of BPSD can be mainly neurobiological (so-called 'primary' symptoms) or mainly environmental and functional ('secondary' symptoms) and that this drives treatment; (ii) the clinical efficacy of psychotropic drugs is driven by their specific profile of receptor affinity; (iii) drug treatment should follow the rules of 'start low-go slow, prescribe and revise'. This article argues in support of the distinction between primary and secondary BPSD, as well as their characteristics, which until now have been just sketchily described in the literature. It also offers comprehensive and pragmatic clinician-oriented recommendations for the treatment of BPSD.

The Relationship between Diet, Depression, and Alzheimer's Disease: A Narrative Review

PURPOSE OF REVIEW

This narrative review evaluates the role of diet in the relationship between depression and Alzheimer's disease (AD).

RECENT FINDINGS

AD and depression are often comorbid, and depression appears to independently increase the future risk of AD. Evidence suggests diet influences the risk of both conditions directly and indirectly. Diet impacts neurochemical and biological processes that may affect the development and progression of depression and cognitive dysfunction. The dietary components offering the greatest protection against depression and AD are yet to be determined. Current evidence highlights the importance of polyphenolic compounds, folate, B vitamins, and polyunsaturated fatty acids, along with adherence to dietary patterns like the Mediterranean diet, which includes multiple beneficial dietary factors.

SUMMARY

The investigation of dietary factors in the prevention of depression and AD is a comparatively young field of research. Comprehensive highly characterised longitudinal datasets and advanced analytical approaches are required to further examine the complex relationship between diet, depression, and AD. There is a critical need for more research in this area to develop effective preventive strategies aimed at maintaining mental and physical health with advancing age.

Towards Defining the Neuroanatomical Basis of Late-Onset Psychiatric Symptoms

Psychiatric symptoms, including changes in emotional processing, are a common feature of many neurodegenerative disorders, such as Alzheimer's disease, dementia with Lewy Bodies, frontotemporal dementia, and Huntington's disease. However, the neuroanatomical basis of emotional symptoms is not well defined; this stands in contrast to the relatively well-understood neuroanatomical correlates of cognitive and motor symptoms in neurodegenerative disorders. Furthermore, psychiatric diagnostic categories, as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM) and International Statistical Classification of Diseases and Related Health Problems (ICD), may have limited applicability in patients with late-onset psychiatric symptoms in the context of neurodegenerative disorders. In this clinical review, we suggest that early-onset and late-onset psychiatric symptoms have distinct etiologies, and that late-onset changes in emotional processing are likely underpinned by neurodegenerative disease. Furthermore, we suggest that an improved understanding of the neuroanatomical correlates of emotional changes in neurodegenerative disease may facilitate diagnosis and future treatment development. Finally, we propose a novel clinical approach, in a preliminary attempt to incorporate late-onset emotional symptoms alongside cognitive and motor symptoms into a clinical "algorithm," with a focus on the neuroanatomy implicated when particular combinations of emotional, cognitive, and motor features are present. We anticipate that this clinical approach will assist with the diagnosis of neurodegenerative disorders, and our proposed schema represents a move towards integrating neurologic and psychiatric classification systems.

Anxiety and depression in Alzheimer's disease: a systematic review of pathogenetic mechanisms and relation to cognitive decline

Objectives

To explore the pathogenetic hypothesis provided to explain the comorbidity of anxious and depressive symptomatology and AD and to assess the association between anxious and depressive symptoms and the AD-related cognitive impairment.

Methods

In October 2020 and March 2021, PsycINFO, Embase, Ovid, and CINAHL were searched for peer-reviewed original articles investigating anxiety and/or depression in AD.

Results

A total of 14,760 studies were identified and 34 papers on AD patients were included in the review. Suggested biological causes of depression and anxiety in AD include higher strychnine-sensitive glycine receptor (GlyRS) functioning and selective reduction of N-methyl-d-aspartate (NMDA) receptor NR2A density, cortical and limbic atrophy, lower resting cortical metabolism, lower CSF Aβ42 and higher t-tau and p-tau levels, and neuritic plaques. At the same time, dysthymia arises in the early stages of AD as an emotional reaction to the progressive cognitive decline and can cause it; anxiety can appear as an initial compensating behaviour; and depression might be related to AD awareness and loss of functional abilities. Affective symptoms and the expression of the depressive symptoms tend to reduce as AD progresses.

Conclusion

The neurodegeneration of areas and circuits dealing with emotions can elicit anxiety and depression in AD. In the early stages of the disease, anxiety and depression could arise as a psychological reaction to AD and due to coping difficulties. In late AD stages, the cognitive impairment reduces the emotional responses and their expression. Anxiety and depression are more intense in early-onset AD, due to the major impact of AD on the individual.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-022-06068-x.

Classification, Prediction, and Concordance of Cognitive and Functional Progression in Patients with Mild Cognitive Impairment in the United States: A Latent Class Analysis

Background:

Progression trajectories of patients with mild cognitive impairment (MCI) are currently not well understood.

Objective:

To classify patients with incident MCI into different latent classes of progression and identify predictors of progression class.

Methods:

Participants with incident MCI were identified from the US National Alzheimer’s Coordinating Center Uniform Data Set (09/2005-02/2019). Clinical Dementia Rating (CDR^®) Dementia Staging Instrument-Sum of Boxes (CDR-SB), Functional Activities Questionnaire (FAQ), and Mini-Mental State Examination (MMSE) score longitudinal trajectories from MCI diagnosis were fitted using growth mixture models. Predictors of progression class were identified using multivariate multinomial logistic regression models; odds ratios (ORs) and 95% confidence intervals (CIs) were reported.

Results:

In total, 21%, 22%, and 57% of participants (N = 830) experienced fast, slow, and no progression on CDR-SB, respectively; for FAQ, these figures were 14%, 23%, and 64%, respectively. CDR-SB and FAQ class membership was concordant for most participants (77%). Older age (≥86 versus≤70 years, OR [95% CI] = 5.26 [1.78–15.54]), one copy of APOE ɛ4 (1.94 [1.08–3.47]), higher baseline CDR-SB (2.46 [1.56–3.88]), lower baseline MMSE (0.85 [0.75–0.97]), and higher baseline FAQ (1.13 [1.02–1.26]) scores were significant predictors of fast progression versus no progression based on CDR-SB (all p < 0.05). Predictors of FAQ class membership were largely similar.

Conclusion:

Approximately a third of participants experienced progression based on CDR-SB or FAQ during the  4-year follow-up period. CDR-SB and FAQ class assignment were concordant for the vast majority of participants. Identified predictors may help the selection of patients at higher risk of progression in future trials.

Psychosocial Protective Factors in Cognitive Aging: A Targeted Review

OBJECTIVE

The lack of disease-modifying pharmacological agents for dementia highlights the critical importance of prevention, but known modifiable factors (e.g., education, physical health and health behaviors, depression, and social isolation) do not fully represent potential intervention targets. Positive psychosocial factors predict cognitive aging outcomes above and beyond known risk factors and may also correspond to upstream determinants that open up new avenues for prevention and intervention, as well as for reducing racial/ethnic inequalities in dementia. In this brief report, I summarize contemporary evidence for three positive psychosocial factors that appear to be particularly relevant to cognitive aging: perceived control, religious involvement, and social relations.

METHODS

Targeted review and synthesis of published studies.

RESULTS

Each of the multidimensional constructs appears to contain "active ingredients" that could help to optimize cognitive aging through disparate mechanisms. Although historically marginalized racial/ethnic groups face disproportionate barriers to accessing certain psychosocial protective factors (e.g., perceived control), these same groups also exhibit naturally occurring sources of psychosocial resilience (e.g., religious involvement) that allow them to achieve better late-life cognitive health than would be otherwise expected. With regard to social relations, converging evidence from disparate studies shows that fostering late-life friendships in particular may have high potential for building cognitive reserve and promoting healthy cognitive aging.

CONCLUSIONS

Positive psychosocial factors represent culturally relevant resources that, through careful research, could ultimately be harnessed to promote better cognitive aging for a growing and increasingly diverse population of older adults.

Modifiable, Non-Modifiable, and Clinical Factors Associated with Progression of Alzheimer's Disease

There is an extensive literature relating to factors associated with the development of Alzheimer's disease (AD), but less is known about factors which may contribute to its progression. This review examined the literature with regard to 15 factors which were suggested by PubMed search to be positively associated with the cognitive and/or neuropathological progression of AD. The factors were grouped as potentially modifiable (vascular risk factors, comorbidities, malnutrition, educational level, inflammation, and oxidative stress), non-modifiable (age at clinical onset, family history of dementia, gender, Apolipoprotein E ɛ4, genetic variants, and altered gene regulation), and clinical (baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs). Although conflicting results were found for the majority of factors, a positive association was found in nearly all studies which investigated the relationship of six factors to AD progression: malnutrition, genetic variants, altered gene regulation, baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs. Whether these or other factors which have been suggested to be associated with AD progression actually influence the rate of decline of AD patients is unclear. Therapeutic approaches which include addressing of modifiable factors associated with AD progression should be considered.

Change in Depression, Confidence, and Physical Function Among Older Adults With Mild Cognitive Impairment

BACKGROUND AND PURPOSE

Nearly a quarter of those in the United States older than 71 years experience mild cognitive impairment. Persons with mild cognitive impairment battle depression and progressive disengagement from daily activities, which contribute to participation restriction and activity limitation. Daily engagement in meaningful activity (DEMA) is a tailored intervention designed to benefit persons with mild cognitive impairment and their caregivers through preserved engagement and supported adjustment to cognitive changes. This secondary analysis was guided by the International Classification of Functioning, Disability and Health (ICF) model. Aims were to (i) explore the extent to which change in self-rated activity performance and physical function can predict change in depressive symptoms, (ii) evaluate for difference in confidence and depressive symptoms at ICF levels of activity and participation, and (iii) quantify the impact of daily engagement at the ICF level of participation on physical function.

METHODS

A secondary analysis was conducted using data from the parent study, which was a 2-group randomized trial involving persons with mild cognitive impairment and their informal caregivers participating in the Indiana Alzheimer Disease Center DEMA program. Quantitative analysis (dyads: DEMA N = 20, Information Support N = 20) examined outcomes at posttest and follow-up. Analysis employed linear regression to model the relationship between explanatory and dependent variables and independent t test to examine for difference in confidence, depression, and physical function.

RESULTS AND DISCUSSION

At posttest, change in self-rated performance predicted change in depressive symptoms. Those in the DEMA group who engaged in activity at the ICF level of participation demonstrated a significant increase in confidence and physical function. Although not significant, the control group posttest results showed a mean decrease in confidence.

CONCLUSIONS

Results demonstrate a positive impact of DEMA on depressive symptoms, confidence, and physical function. Change in occupational performance predicted change in depressive symptoms. Confidence significantly improved among those who engaged at the ICF participation level. A larger, randomized controlled longitudinal trial is needed to better assess the impact of DEMA on physical function, activity, participation restriction, and quality of life.

Home-Based Gait Training Using Rhythmic Auditory Cues in Alzheimer's Disease: Feasibility and Outcomes

Background/Purpose: Although gait disorders occur early in the course of Alzheimer's disease (AD) and increase the risk of falling, methods to improve walking in the home setting are poorly understood. This study aimed to determine the feasibility of a home-based gait training program using rhythmic auditory cues for individuals living with mild to moderately severe AD.

Methods: Participants had probable AD with no other major conditions affecting locomotion. The intervention consisted of eight progressively modified 45-min gait training sessions delivered during home visits over 4 weeks. Experienced physiotherapists provided the therapy that incorporated rhythmic music cues for a range of locomotor tasks and ambulatory activities. On the days when the physiotherapist did not attend, participants independently performed a seated music listening activity. Walking speed, cadence, stride length, double limb support duration, and gait variability (coefficient of variation) were measured using an 8-m GAITRite® computerized walkway immediately before and after the physiotherapy intervention. Participant satisfaction was also assessed using a purpose-designed questionnaire.

Results: Eleven (median age, 77.0 years; median ACE III score, 66/100; 3 females and 8 males) community-dwelling adults living with AD participated. Wilcoxon signed rank tests revealed statistically significant increases in gait speed following the home-based physiotherapy intervention (baseline = 117.5 cm/s, post-intervention = 129.9 cm/s, z = −2.40, p < 0.05). Stride length also improved (baseline = 121.8 cm, post-intervention = 135.6 cm, z = −2.67, p < 0.05). There was no significant change in gait variability. The program was found to be feasible and safe, with no attrition. Participant satisfaction with the home-based music-cued gait training was high, and there were no adverse events.

Conclusion: A progressively modified gait training program using rhythmic auditory cues delivered at home was feasible, safe, and enjoyable. Music-cued gait training can help to reduce the rate of decline in gait stride length and speed in some individuals living with AD.

Trial Registration:http://www.anzctr.org.au/Default.aspx, ACTRN12616000851460.

Universal Trial Number: U1111-1184-5735.

Cognitive and functional progression of dementia in two longitudinal studies

OBJECTIVES

Previous studies have identified several subgroups (ie, latent trajectories) with distinct disease progression among people with dementia. However, the methods and results were not always consistent. This study aims to perform a coordinated analysis of latent trajectories of cognitive and functional progression in dementia across two datasets.

METHODS

Included and analyzed using the same statistical approach were 1628 participants with dementia from the US National Alzheimer's Coordinating Center (NACC) and 331 participants with dementia from the Dutch Clinical Course of Cognition and Comorbidity study (4C-Study). Trajectories of cognition and instrumental activities of daily living (IADL) were modeled jointly in a parallel-process growth mixture model.

RESULTS

Cognition and IADL tended to decline in unison across the two samples. Slow decline in both domains was observed in 26% of the US sample and 74% of the Dutch sample. Rapid decline in cognition and IADL was observed in 7% of the US sample and 26% of the Dutch sample. The majority (67%) of the US sample showed moderate cognitive decline and rapid IADL decline.

CONCLUSIONS

Trajectories of slow and rapid dementia progression were identified in both samples. Despite using the same statistical methods, the number of latent trajectories was not replicated and the relative class sizes differed considerably across datasets. These results call for careful consideration when comparing progression estimates in the literature. In addition, the observed discrepancy between cognitive and functional decline stresses the need to monitor dementia progression across multiple domains.

Cognitive and functional progression in Alzheimer disease: A prediction model of latent classes

OBJECTIVE

We sought to replicate a previously published prediction model for progression, developed in the Cache County Dementia Progression Study, using a clinical cohort from the National Alzheimer's Coordinating Center.

METHODS

We included 1120 incident Alzheimer disease (AD) cases with at least one assessment after diagnosis, originating from 31 AD centres from the United States. Trajectories of the Mini-Mental State Examination (MMSE) and Clinical Dementia Rating sum of boxes (CDR-sb) were modelled jointly over time using parallel-process growth mixture models in order to identify latent classes of trajectories. Bias-corrected multinomial logistic regression was used to identify baseline predictors of class membership and compare these with the predictors found in the Cache County Dementia Progression Study.

RESULTS

The best-fitting model contained 3 classes: Class 1 was the largest (63%) and showed the slowest progression on both MMSE and CDR-sb; classes 2 (22%) and 3 (15%) showed moderate and rapid worsening, respectively. Significant predictors of membership in classes 2 and 3, relative to class 1, were worse baseline MMSE and CDR-sb, higher education, and lack of hypertension. Combining all previously mentioned predictors yielded areas under the receiver operating characteristic curve of 0.70 and 0.75 for classes 2 and 3, respectively, relative to class 1.

CONCLUSIONS

Our replication study confirmed that it is possible to predict trajectories of progression in AD with relatively good accuracy. The class distribution was comparable with that of the original study, with most individuals being members of a class with stable or slow progression. This is important for informing newly diagnosed AD patients and their caregivers.

Depression, functional disability and quality of life among Nigerian older adults: Prevalences and relationships

BACKGROUND

Ageing is associated with increased morbidity, depression and decline in function. These may consequently impair the quality of life (QoL) of older adults.

PURPOSE

This study was used to investigate the prevalence of functional disability, depression, and level of quality of life of older adults residing in Uyo metropolis and its environs, Nigeria.

METHOD

This cross sectional survey involved 206 (116 females and 90 males) older adults with mean age of 69.8±6.7. The World Health Organization Quality of Life-OLD, Functional status Questionnaire (FSQ) and Geriatric Depression Scale (GDS) were used to measure quality of life, functional disability and depression respectively. Data was analysed using frequency counts and percentages and Spearman rank-order correlation coefficient, at 0.05 alpha level.

RESULTS

45.5% of participants had depression, and at least 30% had functional disability in at least one domain, but their quality of life was fairly good (>60.0%) across all domains. Significant correlation existed between depression scores and individual quality of life and functional disability domains and between overall QoL and each functional disability domain (p<0.001).

CONCLUSIONS

Depression and functional disability were quite prevalent among sampled older adults but their QOL was not too severely affected. Since the constructs were interrelated, it seems interventions targeted at depression and functional status may invariably enhance the quality of life of the older adults.

Prevalence of Dementia, Depression, and Mild Cognitive Impairment in a Rural Area of the Island of Crete, Greece

The studies on the prevalence of dementia, depression, and mild cognitive impairment (MCI) in Greece are sparse and show major variations of prevalence depending on geographical areas, nutritional habits, and the way of living. The aim of this door-to-door study was to find the prevalence of dementia, depression, and MCI in a rural Greek population. Four hundred and forty-three individuals older than 61years following the application of specific criteria were diagnosed with: normal cognition, depression, MCI with and without depression, and dementia with and without depression. Four diagnostic methods were used, 2 of which included Mungas correction for age and education. After Mungas adjustment, the results were as follows-depression: 33.9%; MCI: 15.3%; MCI with depression: 8.6%; dementia: 2.0%; and dementia with depression: 7.2%. Dementia is less prevalent compared to global data and other Greek areas. Mild cognitive impairment is more prevalent than dementia. High percentages of depression may be related to low education.

A Comprehensive Review of the Quality and Feasibility of Dementia Assessment Measures: The Dementia Outcomes Measurement Suite

The diagnosis of dementia and the management of its associated symptoms are aided by high-quality assessment tools. However, there is disagreement on the optimal tools among abundant alternatives and lack of consistent quality standards across the different domains of dementia-related change (ie, cognition, severity, function, behavioral and psychological symptoms, delirium, quality of life). Standardization is difficult because the relevance of a measurement tool for health professionals may depend on the clinical setting and on the dementia type and severity. To address this need, we conducted a comprehensive and clinically relevant evidence-based review of dementia-related tools and present a set of recommended tools, the Dementia Outcomes Measurement Suite. The review revealed that considerable development has occurred in terms of assessment of persons with mild cognitive impairment, executive dysfunction, cognitively mediated functional change, and apathy. More research is needed to develop and validate tools to assess health-related quality of life and specific symptoms of dementia including anxiety, wandering, and repetitive vocalizations. This extensive overview of the quality of different measures may serve as a guide for health professionals clinically and for researchers developing new or improved dementia assessment tools.

Early diagnosis of mild cognitive impairment and mild dementia through basic and instrumental activities of daily living: Development of a new evaluation tool

BACKGROUND

Assessment of activities of daily living (ADL) is paramount to determine impairment in everyday functioning and to ensure accurate early diagnosis of neurocognitive disorders. Unfortunately, most common ADL tools are limited in their use in a diagnostic process. This study developed a new evaluation by adopting the items of the Katz Index (basic [b-] ADL) and Lawton Scale (instrumental [i-] ADL), defining them with the terminology of the International Classification of Human Functioning, Disability and Health (ICF), adding the scoring system of the ICF, and adding the possibility to identify underlying causes of limitations in ADL.

METHODS AND FINDINGS

The construct validity, interrater reliability, and discriminative validity of this new evaluation were determined. From 2015 until 2016, older persons (65-93 y) with normal cognitive ageing (healthy comparison [HC]) (n = 79), mild cognitive impairment (MCI) (n = 73), and Alzheimer disease (AD) (n = 71) underwent a diagnostic procedure for neurocognitive disorders at the geriatric day hospital of the Universitair Ziekenhuis Brussel (Brussels, Belgium). Additionally, the ICF-based evaluation for b- and i-ADL was carried out. A global disability index (DI), a cognitive DI (CDI), and a physical DI (PDI) were calculated. The i-ADL-CDI showed high accuracy and higher discriminative power than the Lawton Scale in differentiating HC and MCI (area under the curve [AUC] = 0.895, 95% CI .840-.950, p = .002), MCI and AD (AUC = 0.805, 95% CI .805-.734, p = .010), and HC and AD (AUC = 0.990, 95% CI .978-1.000, p < .001). The b-ADL-DI showed significantly better discriminative accuracy than the Katz Index in differentiating HC and AD (AUC = 0.828, 95% CI .759-.897, p = .039). This study was conducted in a clinically relevant sample. However, heterogeneity between HC, MCI, and AD and the use of different methods of reporting ADL might limit this study.

CONCLUSIONS

This evaluation of b- and i-ADL can contribute to the diagnostic differentiation between cognitively healthy ageing and neurocognitive disorders in older age. This evaluation provides more clarity and nuance in assessing everyday functioning by using an ICF-based terminology and scoring system. Also, the possibility to take underlying causes of limitations into account seems to be valuable since it is crucial to determine the extent to which cognitive decline is responsible for functional impairment in diagnosing neurocognitive disorders. Though further prospective validation is still required, the i-ADL-CDI might be useful in clinical practice since it identifies impairment in i-ADL exclusively because of cognitive limitations.

Longitudinal course of behavioural and psychological symptoms of dementia: systematic review

BACKGROUND

More information about the pattern of behavioural and psychological symptoms of dementia (BPSD) in the course of dementia is needed to inform patients and clinicians and to design future interventions.

AIMS

To determine the persistence and incidence of BPSD and their relation to cognitive function, in individuals with dementia or in cohorts investigated for dementia onset.

METHOD

A systematic literature review analysed the baseline prevalence, persistence and incidence of 11 symptoms. The review was conducted according to established guidelines with the exception that we could not exclude the possibilities of bias in the studies examined.

RESULTS

The 59 included studies showed considerable heterogeneity in their objectives and methods. The symptoms hyperactivity and apathy showed high persistence and incidence; depression and anxiety low or moderate persistence and moderate incidence; and psychotic symptoms low persistence with moderate or low incidence.

CONCLUSIONS

Despite heterogeneity across studies in terms of setting, focus and length of follow-up, there were clinically relevant differences in the longitudinal courses of different BPSD. Apathy was the only symptom with high baseline prevalence, persistence and incidence during the course of dementia.

Trajectories of Depressive Symptomatology in Rural Memory Clinic Patients between Baseline Diagnosis and 1-Year Follow-Up

BACKGROUND/AIMS

To investigate the prevalence and trajectories of depressive symptomatology at 1-year follow-up, and the severity of depressive symptoms, by dementia diagnostic group, as well as to determine the predictors of depressive symptomatology at 1-year follow-up.

METHODS

In rural and remote patients of an interdisciplinary memory clinic between 2004 and 2014, 144 patients diagnosed with no cognitive impairment (NCI), mild cognitive impairment, dementia due to Alzheimer's disease (AD), or non-AD dementia completed the Center for Epidemiologic Studies of Depression Scale to assess depressive symptomatology at both time points.

RESULTS

Among patients with data at both time points, persistence of depressive symptomatology at follow-up occurred in 22.2%, remission in 17.4%, incidence in 13.2%, and absence in 47.2%. The prevalence of depressive symptomatology at baseline and persistence at follow-up were significantly greater in the NCI group than in the other diagnostic groups, but there were no differences in severity. Depressive symptomatology at follow-up was independently associated with depressive symptomatology, lower independence in activities of daily living, and lower self-rating of memory at baseline, as well as with decreased independence in activities of daily living between time points.

CONCLUSION

Future studies should further examine short-term postdiagnostic trajectories in depressive symptomatology in multiple dementia diagnostic groups to inform prognoses and treatment decisions.

Future-Oriented Thought Patterns Associated With Anxiety and Depression in Later Life: The Intriguing Prospects of Prospection

Anxiety and mood disorders in later life are the focus of an increasing amount of intervention research, however basic mechanisms and paradigms explaining etiology and maintenance warrant further exploration. Research on future-oriented thought patterns associated with anxiety and depression in this age group may prove useful, as these disorders are both characterized by a tendency to generate and fixate on threat-related future scenarios that may or may not materialize. Additionally, depression is associated with a reduced expectancy of positive future events. In this paper, we review the literature relevant to future thinking in anxiety and depression in older adults. We focus on the mental construction and anticipation of negative future events, and their underlying neurocognitive mechanisms. We then consider clinical and research implications of anxious and depressive future-oriented thought patterns for older adults. We believe that more research investigating future-oriented thought patterns associated with emotional disorders in later life could improve conceptualization, measurement, and perhaps potential treatments for late-life anxiety and depression.

A Reanalysis of Cognitive-Functional Performance in Older Adults: Investigating the Interaction Between Normal Aging, Mild Cognitive Impairment, Mild Alzheimer's Disease Dementia, and Depression

Depressive symptoms are associated with cognitive-functional impairment in normal aging older adults (NA). However, less is known about this effect on people with mild Cognitive Impairment (MCI) and mild Alzheimer's disease dementia (AD). We investigated this relationship along with the NA-MCI-AD continuum by reanalyzing a previously published dataset. Participants (N = 274) underwent comprehensive neuropsychological assessment including measures of Executive Function, Language/Semantic Memory, Episodic Memory, Visuospatial Abilities, Activities of Daily Living (ADL), and the Geriatric Depression Scale. MANOVA, logistic regression and chi-square tests were performed to assess the association between depression and cognitive-functional performance in each group. In the NA group, depressed participants had a lower performance compared to non-depressed participants in all cognitive and functional domains. However, the same pattern was not observed in the MCI group or in AD. The results suggest a progressive loss of association between depression and worse cognitive-functional performance along the NA-MCI-AD continuum.

Understanding the cognitive underpinnings of functional impairments in early dementia: a review

OBJECTIVES

Early dementia is marked by cognitive and functional impairments, and although studies indicate an association between these, detailed analyses exploring this relationship are rare. It is crucial to understand how specific cognitive deficits underlie functional deficits to develop successful cognitive interventions. This paper reviews the evidence of impairment in everyday functioning and in working, long-term and prospective memory in early dementia. Findings are evaluated with respect to the relationship between cognitive and functional impairments.

METHODS

From the literature searches, 17 studies on everyday functioning and 40 studies on memory were obtained. Studies were only included if patients had an official diagnosis and were in the early stages of dementia.

RESULTS

Complex instrumental activities of daily living were subject to greater impairment than basic activities of daily living. In particular, early dementia patients struggle with finance tasks; a deficit linked to impaired working memory. Regarding cognition, long-term memory is the earliest form of memory to decline as is well recognised. Evidence also indicates deficits in working and prospective memory, with inconsistent evidence about impairments of the former. A major limitation of the literature is a lack of studies assessing individual everyday activities and the associated error patterns that might occur.

CONCLUSION

This review critically assesses the status of translational research for everyday activities in early dementia, an area with critical implications for cognitive-based rehabilitation. Further research is required into the detailed assessment of individual everyday activity and specific memory deficits, in order to effectively map cognitive functions onto functional performance.

Confirmatory factor analysis of the Cornell scale for depression in dementia among patient with dementia of various degrees

BACKGROUND

Depression in dementia is difficult to diagnose. The psychometric qualities of the Cornell scale for depression in dementia and whether depression varies depending on the dementia severity are still controversial.

DESIGN

Cross-sectional study of memory clinic and nursing-home patients.

METHODS

A sample of 1682 patients (750 from memory clinics and 932 from nursing homes) with Clinical dementia rating scale score of one or higher was evaluated with the Cornell scale. The sample was randomly divided into two groups. Exploratory factor analysis was performed on one-half of the patients and confirmatory factor analysis on the other half. It was further analysed whether the scores of the sub-scales differed across CDR score.

RESULTS

A five-factor solution fitted the data best according to both the exploratory and confirmatory factor analysis: 'mood', 'physical', 'cyclic', 'retardation' and 'behaviour'. Further, it was found that the sum score of the Cornell scale differs significantly across dementia severity (p=0.018). The mood and the cyclic sub-scales scores did not vary across dementia severity, unlike the three remaining sub-scales scores.

CONCLUSION

A five-factor solution of the Cornell scale best fitted the data according to both exploratory and confirmatory factor analysis. The mood and cyclic factors' scores did not vary across dementia severity, and this might suggest that they are the core symptoms of depression that are equally present regardless of dementia severity. The other factors scores were higher in severe dementia, which might suggest that these factors are related to the dementia.

The Electrophysiological Phenomenon of Alzheimer's Disease: A Psychopathology Theory

The current understanding of Alzheimer's disease (AD) is based on the Aβ and tau pathology and the resulting neuropathological changes, which are associated with manifested clinical symptoms. However, electrophysiological brain changes may provide a more expansive understanding of AD. Hence, the objective of this systematic review is to propose a theory about the electrophysiological phenomenon of Alzheimer's disease (EPAD). The review of literature resulted from an extensive search of PubMed and MEDLINE databases. One-hundred articles were purposively selected. They provided an understanding of the concepts establishing the theory of EPAD (neuropathological changes, neurochemical changes, metabolic changes, and electrophysiological brain changes). Changes in the electrophysiology of the brain are foundational to the association or interaction of the concepts. Building on Berger's Psychophysical Model, it is evident that electrophysiological brain changes occur and affect cortical areas to generate or manifest symptoms from onset and across the stages of AD, which may be prior to pathological changes. Therefore, the interaction of the concepts demonstrates how the psychopathology results from affected electrophysiology of the brain. The theory of the EPAD provides a theoretical foundation for appropriate measurements of AD without dependence on neuropathological changes. Future research is warranted to further test this theory. Ultimately, this theory contributes to existing knowledge because it shows how electrophysiological changes are useful in understanding the risk and progression of AD across the stages.

Specific cognitive functions and depressive symptoms as predictors of activities of daily living in older adults with heterogeneous cognitive backgrounds

Cognitive functioning influences activities of daily living (ADL). However, studies reporting the association between ADL and neuropsychological performance show inconsistent results regarding what specific cognitive domains are related to each specific functional domains. Additionally, whether depressive symptoms are associated with a worse functional performance in older adults is still under explored. We investigated if specific cognitive domains and depressive symptoms would affect different aspects of ADL. Participants were 274 older adults (96 normal aging participants, 85 patients with mild cognitive impairment, and 93 patients probable with mild Alzheimer's disease dementia) with low formal education (∼4 years). Measures of ADL included three complexity levels: Self-care, Instrumental-Domestic, and Instrumental-Complex. The specific cognitive functions were evaluated through a factorial strategy resulting in four cognitive domains: Executive Functions, Language/Semantic Memory, Episodic Memory, and Visuospatial Abilities. The Geriatric Depression Scale measured depressive symptoms. Multiple linear regression analysis showed executive functions and episodic memory as significant predictors of Instrumental-Domestic ADL, and executive functions, episodic memory and language/semantic memory as predictors of Instrumental-Complex ADL (22 and 28% of explained variance, respectively). Ordinal regression analysis showed the influence of specific cognitive functions and depressive symptoms on each one of the instrumental ADL. We observed a heterogeneous pattern of association with explained variance ranging from 22 to 38%. Different instrumental ADL had specific cognitive predictors and depressive symptoms were predictive of ADL involving social contact. Our results suggest a specific pattern of influence depending on the specific instrumental daily living activity.

Relationship between depressive symptoms and cognition in older, non-demented African Americans

Knowledge of the relationship between depressive symptoms and cognition in older adults has primarily come from studies of clinically depressed, functionally impaired or cognitively impaired individuals, and in predominately White samples. Limited minority representation in depression research exposes the need to examine these associations in more ethnic/racially diverse populations. We sought to examine the relationship between depressive symptoms and cognition in a sample of non-demented older African Americans recruited from surrounding U.S. cities of New York, Greensboro, Miami, and Nashville (N=944). Depressive symptoms were evaluated with the Geriatric Depression Scale (GDS). Cognition was evaluated with a comprehensive neuropsychological battery. Test scores were summarized into attention, executive function, memory, language, and processing speed composites. Controlling for age, education, reading level, and sex, African American older adults who endorsed more symptoms obtained significantly lower scores on measures of memory, language, processing speed, and executive functioning. Further investigation of the causal pathway underlying this association, as well as potential mediators of the relationship between depressive symptoms and cognitive test performance among older African Americans, such as cardiovascular and cerebrovascular disease, may offer potential avenues for intervention.

Cognitive declines precede and predict functional declines in aging and Alzheimer's disease

OBJECTIVE

To investigate the temporal ordering of cognitive and functional declines separately in older adults with or without Alzheimer's disease (AD).

DESIGN AND SETTING

A community-based longitudinal study of aging and dementia in Northern Manhattan (Washington Heights/Hamilton Heights Inwood Columbia Aging Project) and a multicenter, clinic-based longitudinal study of prevalent AD at Columbia University Medical Center, Johns Hopkins School of Medicine, Massachusetts General Hospital, and the Hôpital de la Salpêtrière in Paris, France (the Predictors Study).

PARTICIPANTS

3,443 initially non-demented older adults (612 with eventual incident dementia) and 517 patients with AD.

MAIN OUTCOME MEASURES

Cognitive measures included the modified Mini-Mental State Exam and composite scores of memory and language derived from a standardized neuropsychological battery. Function was measured with the Blessed Dementia Rating Scale, completed by the participant (in the sample of non-demented older adults) or an informant (in the sample of prevalent AD patients). Data were analyzed with autoregressive cross-lagged panel analysis.

RESULTS

Cognitive scores more consistently predicted subsequent functional abilities than vice versa in non-demented older adults, participants with eventual incident dementia, and patients with prevalent AD.

CONCLUSIONS

Cognitive declines appear to precede and cause functional declines prior to and following dementia diagnosis. Standardized neuropsychological tests are valid predictors of later functional changes in both non-demented and demented older adults.