Differential impact of apathy and depression in the development of dementia in mild cognitive impairment patients

Effects of dance therapy on cognitive and mental health in adults aged 55 years and older with mild cognitive impairment: a systematic review and meta-analysis

BACKGROUND

Individuals with mild cognitive impairment are at high risk of developing dementia. Dance therapy has promising applications in delaying cognitive decline. However, the effectiveness of dance therapy for older adults with mild cognitive impairment is unclear. The objective of this review was to evaluate the effectiveness of dance therapy on global cognitive function, specific cognitive subdomains, quality of life, and mental health in older adults with mild cognitive impairment to enrich health management strategies for dementia.

METHODS

Electronic databases and grey literature were searched from inception up to September 23, 2023. The language was limited to English and Chinese. Relevant studies were screened and assessed for risk of bias. A meta-analysis and subgroup analyses stratified by measurement instrument, dance type, intervention duration, and frequency were conducted using the STATA 16.0 software. This review was conducted in accordance with the PRISMA guidelines.

RESULTS

Ten studies involving 984 participants aged 55 years and over who met the eligibility criteria were included. Dance therapy significantly improved global cognitive function, memory, executive function, attention, language, and mental health (i.e., depression and neuropsychiatric symptoms). However, the effects of dance therapy on processing speed, visuospatial ability, and quality of life in older adults with mild cognitive impairment remain inconclusive. Moreover, dance interventions of longer duration (> 3 months) improved global cognition more than shorter interventions.

CONCLUSION

This review reported that dance therapy was effective in improving global cognitive function, memory, executive function, attention, language, and mental health (i.e., depression and neuropsychiatric symptoms). Hence, it may be an effective non-pharmacological complementary treatment for older adults with mild cognitive impairment.

The Interface between Depression and Alzheimer's Disease. A Comprehensive Approach

Depression and Alzheimer's disease (AD) are frequent interacting diseases in the elderly with a negative impact on the quality of life of patients and caregivers. Late-life depression may be regarded either as an early symptom of AD or a risk factor for AD, depending on the context. This review was focused on the latest developments in the fields of the neurobiological basis and treatment of depression in AD. We found that some plausible hypotheses are emerging to correlate with depression in AD, such as neuroinflammation and dysimmune regulation. It seems that depression is not related to amyloid deposition, but this issue is not completely resolved. The response to antidepressants is controversial according to the evidence from 10 small double-blind randomized placebo-controlled clinical trials with antidepressants in AD patients with depression: four with sertraline, one with three arms (sertraline, mirtazapine, placebo), one with fluoxetine, one with imipramine, one with clomipramine, one with escitalopram, and one with vortioxetine. The total number of treated patients completing the trials was 638. The main criterion of a positive response was a reduction in the scores of clinical scales for depression of at least 50%. The weighted OR (odds ratio) was calculated with the method of Mantel-Haenszel: 1.29; 95% CI: 0.77-2.16. No significant differences were found compared with placebo. Antidepressants did not have a meaningful negative influence on cognition, which was measured with the mini-mental state examination (MMSE) in 18 clinical trials. Alternatives other than drugs are also discussed. Although there have been important advances in this field, pathophysiology and treatment deserve further research.

Putative pathological mechanisms of late-life depression and Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by progressive impairment in cognition and memory. AD is accompanied by several neuropsychiatric symptoms, with depression being the most prominent. Although depression has long been known to be associated with AD, controversial findings from preclinical and clinical studies have obscured the precise nature of this association. However recent evidence suggests that depression could be a prodrome or harbinger of AD. Evidence indicates that the major central serotonergic nucleus-the dorsal raphe nucleus (DRN)-shows very early AD pathology: neurofibrillary tangles made of hyperphosphorylated tau protein and degenerated neurites. AD and depression share common pathophysiologies, including functional deficits of the serotonin (5-HT) system. 5-HT receptors have modulatory effects on the progression of AD pathology i.e., reduction in Aβ load, increased hyper-phosphorylation of tau, decreased oxidative stress etc. Moreover, preclinical models show a role for specific channelopathies that result in abnormal regional activational and neuroplasticity patterns. One of these concerns the pathological upregulation of the small conductance calcium-activated potassium (SK) channel in corticolimbic structure. This has also been observed in the DRN in both diseases. The SKC is a key regulator of cell excitability and long-term potentiation (LTP). SKC over-expression is positively correlated with aging and cognitive decline, and is evident in AD. Pharmacological blockade of SKCs has been reported to reverse symptoms of depression and AD. Thus, aberrant SKC functioning could be related to depression pathophysiology and diverts its late-life progression towards the development of AD. We summarize findings from preclinical and clinical studies suggesting a molecular linkage between depression and AD pathology. We also provide a rationale for considering SKCs as a novel pharmacological target for the treatment of AD-associated symptoms.

The Differential Role of Executive Apathy in Alzheimer's Disease Dementia, Mild Cognitive Impairment and Healthy Cognitive Ageing

The objective of the present work was to compare the levels of executive, emotional, and initiation apathy in individuals with mild cognitive impairment (MCI), mild Alzheimer's disease dementia (ADD), and cognitively intact healthy controls (HCs). Fifty-two patients with mild ADD, 40 individuals with MCI, and 37 cognitively intact individuals were included in the current study. The participants were consecutive visitors to the Outpatient Memory Clinic of "Nestor" Alzheimer's Center. The symptoms of apathy were measured with the dimensional apathy scale. Analyses showed that ADD patients had significantly higher degrees of executive, emotional, initiation, and overall apathy compared with both the MCI group and the HCs. Additionally, a significant difference was observed in the dimension of executive apathy between individuals with MCI and the HCs. In conclusion, the dimension of executive apathy was the most sensitive measure regarding the differentiation of individuals with mild ADD or MCI and HCs. Hence, detailed evaluation of executive apathy in older individuals referred to a memory clinic may provide useful information contributing to their diagnostic categorization and to the differentiation between neurocognitive disorders and healthy cognitive ageing.

Apathy as a Predictor of Conversion from Mild Cognitive Impairment to Alzheimer's Disease: A Texas Alzheimer's Research and Care Consortium (TARCC) Cohort-Based Analysis

BACKGROUND

Apathy is among the neuropsychiatric symptoms frequently observed in people with cognitive impairment. It has been postulated to be a potential predictor of conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD).

OBJECTIVE

To detect conversion rates from MCI to AD, and to determine the effect of apathy on the progression to AD in patients with MCI enrolled in the Texas Alzheimer's Research and Care Consortium (TARCC) cohort.

METHODS

Apathy was determined by a positive response to the respective item in the Neuropsychiatric Inventory -Questionnaire (NPI-Q) completed by family members or caregivers. The final dataset included 2,897 observations from 1,092 individuals with MCI at the baseline. Kaplan-Meier survival curves were estimated to provide indices of the probability of conversion to AD over time across all individuals as well as between those with and without apathy. Cox proportional hazards regression measured the hazard associated with apathy and several other predictors of interest.

RESULTS

Over a period of 8.21 years, 17.3% of individuals had conversion from MCI to AD (n = 190 of 1,092 total individuals) across observations. The median time-to-conversion across all participants was 6.41 years. Comparing individuals with apathy (n = 158) versus without apathy (n = 934), 36.1% and 14.2% had conversion to AD, respectively. The median time-to-conversion was 3.79 years for individuals with apathy and 6.83 years for individuals without apathy. Cox proportional hazards regression found significant effects of several predictors, including apathy, on time-to-conversion. Age and cognitive performance were found to moderate the relationship between apathy and time-to-conversion.

CONCLUSIONS

Apathy is associated with progression from MCI to AD, suggesting that it might improve risk prediction and aid targeted intervention delivery.

Apathy as a Predictor for Conversion From Mild Cognitive Impairment to Dementia: A Systematic Review and Meta-Analysis of Longitudinal Studies

BACKGROUND

Apathy is one of the most prevalent neurobehavioral manifestations in mild cognitive impairment (MCI) and is included among the behavioral and psychological symptoms of dementia (BPSD). Studies suggest that the presence of apathy could be associated with increased dementia risk. The role of apathy in conversion from MCI to dementia, and whether apathy could be a relevant predictor for dementia progression, are still matters of investigation.

AIM

To study the relationship between apathy and progression to dementia in individuals with MCI.

METHODS

A systematic literature search in Medline, Embase, Cochrane Library, Epistemonikos, PsychINFO, and CINAHL was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search included longitudinal studies reporting on the association between apathy and dementia.

RESULTS

The main outcome was pooled unadjusted hazard ratios (HR) of apathy in dementia conversion and included 11 studies with 9504 individuals. There was a significant association between apathy and dementia conversion, HR = 1.54; 95% CI, 1.29, 1.84. Subgroup analysis showed a significant association between apathy and progression to AD.

CONCLUSION

Apathy was associated with an increased risk of conversion to AD and all-cause dementia in patients with MCI. The role of apathy as a marker for incident dementia needs to be investigated in large, high-quality studies.

Different Trajectories of Apathy and Depression Among Subjective Cognitive Impairment Individuals with or without Conversion to Dementia: Results from the Memento Cohort in France

BACKGROUND

Apathy and depression are two early behavioral symptoms in Alzheimer's disease (AD) and related disorders that often occur prior to the onset of cognitive decline and memory disturbances. Both have been associated with an increased risk of conversion to dementia, with a distinct neuropathology.

OBJECTIVE

The assessment of the trajectories of apathy and depression and their independent impact on dementia conversion.

METHODS

Apathy and Depression were measured using the Neuropsychiatric Inventory for caregiver (NPI) and clinician (NPI-C), among the nondemented individuals reporting subjective cognitive decline (SCD) at baseline. They were followed up over a 60-month period. Some converted to dementia, according to the methodology carried out by the French Memento Cohort.

RESULTS

Among individuals with SCD (n = 2,323), the levels of apathy and depression were low and did not evolve significantly over the 60-month period, despite a trend in apathy increasing as of month 24. Regarding SCD individuals who converted to dementia within the 60-month period (n = 27), the prevalence of depression remained globally steady, while the levels of apathy increased over time.

CONCLUSION

Apathy and depression have different trajectories among individuals with SCD and apathy alone is more likely-compared to depression-to be associated with conversion to dementia.

Apathy in depression: An arterial spin labeling perfusion MRI study

INTRODUCTION

Apathy, as defined as a deficit in goal-directed behaviors, is a critical clinical dimension in depression associated with chronic impairment. Little is known about its cerebral perfusion specificities in depression. To explore neurovascular mechanisms underpinning apathy in depression by pseudo-continuous arterial spin labeling (pCASL) magnetic resonance imaging (MRI).

METHODS

Perfusion imaging analysis was performed on 90 depressed patients included in a prospective study between November 2014 and February 2017. Imaging data included anatomical 3D T1-weighted and perfusion pCASL sequences. A multiple regression analysis relating the quantified cerebral blood flow (CBF) in different regions of interest defined from the FreeSurfer atlas, to the Apathy Evaluation Scale (AES) total score was conducted.

RESULTS

After confound adjustment (demographics, disease and clinical characteristics) and correction for multiple comparisons, we observed a strong negative relationship between the CBF in the left anterior cingulate cortex (ACC) and the AES score (standardized beta = -0.74, corrected p value = 0.0008).

CONCLUSION

Our results emphasized the left ACC as a key region involved in apathy severity in a population of depressed participants. Perfusion correlates of apathy in depression evidenced in this study may contribute to characterize different phenotypes of depression.

Prediction of Cognitive Decline by Behavioral Symptoms in Neuropsychiatric Disorders

Background: Neuropsychiatric disorders are described by their neurological, behavioral, and cognitive symptoms. However, behavioral symptoms may often be overlooked due to the current approach in neurology. Objectives: This study investigated the relationship between behavioral symptoms and cognitive functioning in neurological disorders. The second aim was to predict neurocognitive patterns by behavioral symptoms as independent variables. Methods: Behavioral symptoms were collected based on semi-structured neuropsychiatric interviews with 211 patients admitted to the neuropsychiatry department of Ayatollah Kashani hospital in Isfahan by both a neuropsychiatry fellow and an attending neuropsychiatrist. A neuropsychiatry fellow assessed all patients using the neuropsychiatry unit cognitive (NUCog) assessment tool. We used a generalized linear model (GLM) to indicate the effect of behavioral symptoms on the risk of decline in cognitive domains. Due to the use of all available samples, this study had no age limit, and the patients were 15 to 92 years old. Results: The regression coefficient of NUCog subscale scores for behavioral symptoms using GLM revealed that education level had a positive relationship with the scores of attention (P < 0.001), visuoconstruction (P < 0.001), memory (P < 0.001), executive function (P < 0.001), language (P < 0.001), and the total score of NUCog (P < 0.001). Patients with apathy had lower scores on the memory subscale (P = 0.002) and total NUCog (P = 0.021). Similarly, patients with delusion had lower scores on memory (P = 0.006) and executive function (P = 0.026). There was a negative relationship between agitation and attention (P = 0.049), visuoconstruction (P = 0.015), memory (P = 0.018), executive function (P = 0.005), and total score of NUCog (P = 0.007). Sleep disturbances were accompanied by lower memory scores (P = 0.056) and lower mean NUCog scores (P = 0.052). Visual hallucination was associated with declined performance in attention (P = 0.057). Conclusions: Behavioral assessment can help predict cognitive patterns in patients with neurobehavioral syndromes.

Effectiveness of life story book intervention on apathy and verbal fluency in people with dementia

OBJECTIVES

This study determined whether the individual intervention of using life story books (LSBs) improves apathy and verbal fluency in people with dementia (PWD).

METHODS

The intervention group (n = 43) underwent 3 interviews in the 10 weeks following an initial assessment. Based on the information obtained, LSBs were developed; participants received individual interventions weekly, five times for four weeks. They also received a final assessment 12 weeks after the end of the intervention. Primary outcome measures comprised the Categorical Verbal Fluency Test (CFT) and the Neuropsychiatric Inventory-Nursing Home Apathy sub-item. The control group (n = 32) underwent initial and final assessments at intervals of 28 weeks while receiving the best care services.

RESULTS

CFT scores for participants with mild to moderate dementia increased from 4.3 to 5.3 (P < .05) and the interaction effect of group and data collection timing was significant (p < .05). Apathy score for participants with severe dementia also improved from 4.5 to 2.5 (P < .05) immediately after the intervention period.

CONCLUSIONS

LSB is a comprehensive communication tool that encourages apathy and verbal fluency.

CLINICAL IMPLICATIONS

The use of LSB may allow caregivers to achieve intervention effects on apathy and verbal fluency in PWD.

Lipid Peroxidation as a Marker of Apathy and Executive Dysfunction in Patients at Risk for Vascular Cognitive Impairment

Background: The co-occurrence of apathy and executive dysfunction, a correlate of vascular cognitive impairment (VCI), is highly prevalent, yet facilitating factors are largely unknown. Objective: This study investigates the relationship between lipid peroxidation, apathy, and executive dysfunction in patients at risk for VCI. Methods: In participants with coronary artery disease, who are at a high risk of VCI, apathy (Apathy Evaluation Scale), and executive function (composite z-score based on age and education population norms from trails making test B, animal naming, and phonemic fluency tests) were assessed. Serum concentrations of an early (lipid hydroperoxide (LPH)) and late (8-isoprostane (8-ISO)) lipid peroxidation marker, were measured and the 8-ISO/LPH ratio was calculated. Results: Participants (n = 206, age±SD = 63.0±7.5, 80% men, total years of education = 15.9±3.4, AES score = 28.3±8.8, executive function = 0±1) demonstrated significantly different 8-ISO/LPH ratios between groups (F(3, 202) = 10.915, p <  0.001) with increasing levels in the following order: no apathy or executive dysfunction, only executive dysfunction (executive function composite score≤–1), only apathy (AES≥28), and both apathy and executive dysfunction. A model adjusting for demographics showed that lipid peroxidation was associated with both apathy (B(SE) = 4.63 (0.954), t = 4.852, p <  0.001) and executive function (B(SE) = –0.19 (0.079), t = –2.377, p = 0.018). However, when controlling for both demographics and vascular risk factors, lipid peroxidation was associated with only apathy (B(SE) = 3.11 (0.987), t = 3.149, p = 0.002). Conclusion: The results highlight a potentially important involvement of lipid peroxidation in the co-occurrence of apathy and executive dysfunction in those at risk for VCI.

Mediation Analyses of the Role of Apathy on Motoric Cognitive Outcomes

Recent literature indicates that apathy is associated with poor cognitive and functional outcomes in older adults, including motoric cognitive risk syndrome (MCR), a predementia syndrome. However, the underlying biological pathway is unknown. The objectives of this study were to (1) examine the cross-sectional associations between inflammatory cytokines (Interleukin 6 (IL-6) and C-Reactive Protein (CRP)) and apathy and (2) explore the direct and indirect relationships of apathy and motoric cognitive outcomes as it relates to important cognitive risk factors. N = 347 older adults (≥65 years old) enrolled in the Central Control of Mobility in Aging Study (CCMA). Linear and logic regression models showed that IL-6, but not CRP was significantly associated with apathy adjusted for age, gender, and years of education (β = 0.037, 95% CI: 0.002-0.072, p = 0.04). Apathy was associated with a slower gait velocity (β = -14.45, 95% CI: -24.89-4.01, p = 0.01). Mediation analyses demonstrated that IL-6 modestly mediates the relationship between apathy and gait velocity, while apathy mediated the relationships between dysphoria and multimorbidity and gait velocity. Overall, our findings indicate that apathy may be an early predictor of motoric cognitive decline. Inflammation plays a modest role, but the underlying biology of apathy warrants further investigation.

Apathy Is the Best Dimension to Consider for Awareness Assessment in Alzheimer’s Disease

Previous studies have reported the major role of apathy in awareness assessment among Alzheimer’s patients using the patient-caregiver discrepancy method, whatever the awareness dimension assessed. Using the Apathy Evaluation Scales among other awareness scales, we report that apathy is the sole awareness dimension distinguishing healthy controls (25), mild (57) and moderate-to-moderately-severe (11) Alzheimer’s patients. A linear regression showed that the Mini-Mental State Examination score used as a risk factor for non-awareness was the only factor associated with awareness of apathy and was the best predictor. This suggests that apathy is the most discriminant dimension for awareness assessment in Alzheimer’s disease.

Apathy as a Treatment Target in Alzheimer's Disease: Implications for Clinical Trials

Apathy is one of the most prevalent, stable and persistent neuropsychiatric symptom across the neurocognitive disorders spectrum. Recent advances in understanding of phenomenology, neurobiology and intervention trials highlight apathy as an important target for clinical intervention. We conducted a comprehensive review and critical evaluation of recent advances to determine the evidence-based suggestions for future trial designs. This review focused on 4 key areas: 1) pre-dementia states; 2) assessment; 3) mechanisms/biomarkers and 4) treatment/intervention efficacy. Considerable progress has been made in understanding apathy as a treatment target and appreciating pharmacological and non-pharmacological apathy treatment interventions. Areas requiring greater investigation include: diagnostic procedures, symptom measurement, understanding the biological mechanisms/biomarkers of apathy, and a well-formed approach to the development of treatment strategies. A better understanding of the subdomains and biological mechanisms of apathy will advance apathy as a treatment target for clinical trials.

Patterns of Symptom Tracking by Caregivers and Patients With Dementia and Mild Cognitive Impairment: Cross-sectional Study

Background

Individuals with dementia and mild cognitive impairment (MCI) experience a wide variety of symptoms and challenges that trouble them. To address this heterogeneity, numerous standardized tests are used for diagnosis and prognosis. myGoalNav Dementia is a web-based tool that allows individuals with impairments and their caregivers to identify and track outcomes of greatest importance to them, which may be a less arbitrary and more sensitive way of capturing meaningful change.

Objective

We aim to explore the most frequent and important symptoms and challenges reported by caregivers and people with dementia and MCI and how this varies according to disease severity.

Methods

This cross-sectional study involved 3909 web-based myGoalNav users (mostly caregivers of people with dementia or MCI) who completed symptom profiles between 2006 and 2019. To make a symptom profile, users selected their most personally meaningful or troublesome dementia-related symptoms to track over time. Users were also asked to rank their chosen symptoms from least to most important, which we called the symptom potency. As the stage of disease for these web-based users was unknown, we applied a supervised staging algorithm, previously trained on clinician-derived data, to classify each profile into 1 of 4 stages: MCI and mild, moderate, and severe dementia. Across these stages, we compared symptom tracking frequency, symptom potency, and the relationship between frequency and potency.

Results

Applying the staging algorithm to the 3909 user profiles resulted in 917 (23.46%) MCI, 1596 (40.83%) mild dementia, 514 (13.15%) moderate dementia, and 882 (22.56%) severe dementia profiles. We found that the most frequent symptoms in MCI and mild dementia profiles were similar and comprised early hallmarks of dementia (eg, recent memory and language difficulty). As the stage increased to moderate and severe, the most frequent symptoms were characteristic of loss of independent function (eg, incontinence) and behavioral problems (eg, aggression). The most potent symptoms were similar between stages and generally reflected disruptions in everyday life (eg, problems with hobbies or games, travel, and looking after grandchildren). Symptom frequency was negatively correlated with potency at all stages, and the strength of this relationship increased with increasing disease severity.

Conclusions

Our results emphasize the importance of patient-centricity in MCI and dementia studies and illustrate the valuable real-world evidence that can be collected with digital tools. Here, the most frequent symptoms across the stages reflected our understanding of the typical disease progression. However, the symptoms that were ranked as most personally important by users were generally among the least frequently selected. Through individualization, patient-centered instruments such as myGoalNav can complement standardized measures by capturing these infrequent but potent outcomes.

Neuropsychiatric Profile as a Predictor of Cognitive Decline in Mild Cognitive Impairment

Introduction: Mild cognitive impairment is often associated with affective and other neuropsychiatric symptoms (NPS). This co-occurrence might have a relevant impact on disease progression, from MCI to dementia.

Objective: The aim of this study was to explore the trajectories of cognitive decline in an MCI sample from a memory clinic, taking into consideration a perspective of isolated cognitive functions and based on NPS clusters, accounting for the different comorbid symptoms collected at their baseline visit.

Methods: A total of 2,137 MCI patients were monitored over a 2.4-year period. Four clusters of NPS (i.e., Irritability, Apathy, Anxiety/Depression and Asymptomatic) were used to run linear mixed models to explore the interaction of cluster with time on cognitive trajectories using a comprehensive neuropsychological battery (NBACE) administered at baseline and at the three subsequent follow-ups.

Results: A significant interaction between cluster and time in cognitive decline was found when verbal learning and cued-recall were explored (p = 0.002 for both memory functions). For verbal learning, the Irritability cluster had the largest effect size (0.69), whereas the Asymptomatic cluster showed the smallest effect size (0.22). For cued-recall, the Irritability cluster had the largest effect size among groups (0.64), and Anxiety/Depression had the smallest effect size (0.21).

Conclusions: In MCI patients, the Irritability and Apathy NPS clusters shared similar patterns of worsening in memory functioning, which could point to these NPS as risk factors of a faster cognitive decline, acting as early prognostic markers and helping in the diagnostic process.

Comorbidity Trajectories Associated With Alzheimer's Disease: A Matched Case-Control Study in a United States Claims Database

Background: Trajectories of comorbidities among individuals at risk of Alzheimer's disease (AD) may differ from those aging without AD clinical syndrome. Therefore, characterizing the comorbidity burden and pattern associated with AD risk may facilitate earlier detection, enable timely intervention, and help slow the rate of cognitive and functional decline in AD. This case-control study was performed to compare the prevalence of comorbidities between AD cases and controls during the 5 years prior to diagnosis (or index date for controls); and to identify comorbidities with a differential time-dependent prevalence trajectory during the 5 years prior to AD diagnosis. Methods: Incident AD cases and individually matched controls were identified in a United States claims database between January 1, 2000 and December 31, 2016. AD status and comorbidities were defined based on the presence of diagnosis codes in administrative claims records. Generalized estimating equations were used to assess evidence of changes over time and between AD and controls. A principal component analysis and hierarchical clustering was performed to identify groups of AD-related comorbidities with respect to prevalence changes over time (or trajectory), and differences between AD and controls. Results: Data from 186,064 individuals in the IBM MarketScan Commercial Claims and Medicare Supplementary databases were analyzed (93,032 AD cases and 93,032 non-AD controls). In total, there were 177 comorbidities with a ≥ 5% prevalence. Five main clusters of comorbidities were identified. Clusters differed between AD cases and controls in the overall magnitude of association with AD, in their diverging time trajectories, and in comorbidity prevalence. Three clusters contained comorbidities that notably increased in frequency over time in AD cases but not in controls during the 5-year period before AD diagnosis. Comorbidities in these clusters were related to the early signs and/or symptoms of AD, psychiatric and mood disorders, cerebrovascular disease, history of hazard and injuries, and metabolic, cardiovascular, and respiratory complaints. Conclusion: We demonstrated a greater comorbidity burden among those who later developed AD vs. controls, and identified comorbidity clusters that could distinguish these two groups. Further investigation of comorbidity burden is warranted to facilitate early detection of individuals at risk of developing AD.

The Apathy Evaluation Scale (AES-C): Psychometric Properties and Invariance of Italian Version in Mild Cognitive Impairment and Alzheimer's Disease

Apathy is a neuropsychiatric symptom observed in different neurological and psychiatric disorders. Although apathy is considered a symptom, it has been recently reconsidered as a syndrome characterised by three dimensions: cognitive symptoms, affective symptoms and behavioural symptoms. Recent studies have shown that apathy can be considered as a prodromal symptom of Alzheimer's disease (AD), but also an indicator of the transition from mild cognitive impairment to AD. According to this scenario, an early detection of apathy in subjects with Mild Cognitive Impairment (MCI) and Mild AD can be a valid psychometric strategy to improve an early diagnosis and promote a prompt intervention. The Apathy Evaluation Scale is a validated tool composed of 18 items that assess and quantify emotional, behavioural and cognitive aspects of apathy. The aim of this study is to assess the specific reliability and validity of the Italian version of the Apathy Evaluation Scale-Clinician Version (AES-C) to detect apathy both in amnestic MCI and mild AD patients. In the present paper, we therefore examined the psychometric properties and the invariance of the Italian Version of the AES-C conducted on a sample composed of an experimental group of amnestic MCI and AD patients (N = 107) and a control group (N = 107) constituted by Age- and Sex-matched healthy controls. Results confirm the goodness of the scale. Confirmatory factory analysis confirmed that the AES-C Italian Version presents the same stability of one second-order factor and three first-order factors identified in the original version, and all items are predicted by a single general factor. Moreover, the scale was found to be invariant across both populations. Moreover, reliability and discriminant analysis showed good values. We found in the experimental group a negative correlation between the AES-C and Frontal Assessment Battery (FAB) (rs = -0.21, p < 0.001) and Mini Mental State Examination (MMSE) (rs = -0.04, p < 0.001), while a positive correlation was found between the AES-C and Hamilton psychiatric Rating scale for Depression (HAM-D) scores (rs = 0.58, p < 0.001) Overall, our data demonstrated the validity of the Italian version of the AES-C for the assessment of apathy both in MCI and in AD patients.

Affective Neuropsychiatric Symptoms as Early Signs of Dementia Risk in Older Adults

BACKGROUND

Affective neuropsychiatric symptoms (aNPS: depression, anxiety, apathy, irritability) have been linked to increased dementia risk. However, less is known whether this association is independent of Alzheimer's disease (AD) pathophysiology.

OBJECTIVE

To investigate the contribution of early aNPS to dementia risk in cognitively normal (CN) older adults and mild cognitive impairment (MCI) patients, with and without AD biomarker abnormality.

METHODS

Participants included 763 community-dwelling, stroke-free older adults identified as CN and 617 with MCI at baseline, drawn from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Baseline assessments included a neuropsychological battery, the Neuropsychiatric Inventory (NPI), and apolipoprotein E ɛ4 (ApoE4) genotyping. A participant subset completed cerebrospinal fluid (CSF) AD biomarker assessment. Time to progression to dementia was measured based on months at follow-up when an individual was diagnosed with dementia, over the follow-up period of 48 months.

RESULTS

Latent class analysis identified 3 subgroups of older adults in CN and MCI, indicated by the baseline profiles of neuropsychiatric symptoms (NPS). Subgroups with higher aNPS were at increased risk of progression to dementia in both CN (HR = 3.65, 95% CI [1.80, 7.40]) and MCI (HR = 1.52, 95% CI [1.16, 2.00]; HR = 1.86 [1.05, 3.30]) groups, adjusting for age, sex, global cognition, and ApoE4, compared with their counterparts with minimal NPS. There was no difference between higher aNPS and minimal NPS subgroups in their CSF AD biomarker profiles.

CONCLUSION

Findings suggest that aNPS may represent a neurobiological vulnerability that uniquely contribute to the dementia risk, independent of AD biomarker profiles.

Revisiting Apathy in Alzheimer's Disease: From Conceptualization to Therapeutic Approaches

Apathy is a neurobehavioral syndrome characterized by impaired motivation for goal-directed behaviors and cognitive activity, alongside blunted affect. Apathy is a common neuropsychiatric syndrome in Alzheimer's disease (AD), with a 5-year prevalence over 70%. Apathy also serves as a prognostic indicator, correlating with the progression of AD. Despite advances in its conceptualization and understanding of its neural basis, there is very limited empirical evidence to support the available strategies for the treatment of apathy in AD. Given its complex pathophysiology, including distinct substrates for different apathy dimensions (affective, cognitive, and behavioral), it is unlikely that a single pharmacological or nonpharmacological strategy will be effective for all cases of apathy in AD. High-quality evidence research is needed to better understand the role of specific strategies aiming at a personalized approach.

Loneliness, Sense of Control, and Risk of Dementia in Healthy Older Adults: A Moderated Mediation Analysis

Objectives: Despite the rising prevalence of dementia, little research has been conducted to identify modifiable psychological factors that alleviate the risk of dementia in older adults and the underlying mechanisms. Given that loneliness is, in part, concomitant with a weakened sense of control, we examined whether sense of control would mediate the relation between loneliness and dementia risk. Further, considering that working -memory capacity is a critical cognitive resource that serves as a buffer against age-related cognitive decline, we examined a second-order moderated mediational model whereby working-memory capacity moderates the relation between control beliefs and dementia risk in older adults.

METHODS

We administered a series of measures to older community-dwelling adults (ages 60-93; N = 69), including the participant-rated AD8 to assess the risk of dementia. Using the PROCESS macro, we examined the moderated mediation model for the relation between loneliness, sense of control, and dementia risk.

RESULTS

We found that sense of control significantly mediated the relation between loneliness and risk of dementia. Moreover, the indirect effect of loneliness on dementia risk via lowered sense of control was significant only in individuals with poorer working-memory capacity. Notably, these findings held true when important covariates were controlled for.

CONCLUSIONS

Our findings underscore the critical role of control beliefs and working memory in protecting against dementia risk.

CLINICAL IMPLICATIONS

Our findings have implications for intervention programs that target alleviating dementia risk and promoting healthy aging in older adults by improving socioemotional health and cognitive functioning.

Apathy symptoms increase the risk of dementia conversion: a case-matching cohort study on patients with post-stroke mild cognitive impairment in China

BACKGROUND

Apathy is a neuropsychiatric symptom frequently observed in patients with cognitive impairment. It has been found to be a predictor of conversion from mild cognitive impairment (MCI) to dementia of Alzheimer disease type. However, this association between apathy and dementia conversion has not yet been confirmed in vascular MCI, especially post-stroke MCI. The aim of this study was to evaluate whether apathy would increase the risk of dementia conversion in patients with post-stroke MCI after 6 months.

METHOD

A prospective multi-centre cohort study was performed in 14 clinics in seven provinces and cities of China. A total of 989 subjects were included 2 weeks to 6 months after stroke, and met the diagnostic criteria of International Working Group for MCI. Symptoms of apathy were assessed using the apathy subscale of Geriatric Depression Scale. Subjects were divided into an apathy group (n = 128) and a non-apathy group (n = 861). The primary outcome was the dementia conversion after 6 months. To eliminate potential biases, subjects were chosen from 861 non-apathy patients with similarity in seven potential predictors of cognitive impairment to match with the apathy group (n = 128) at a 1:1 ratio, as a matched non-apathy group (n = 128). The dementia conversion rate was compared between the apathy group (n = 128) and its correspondingly matched non-apathy group (n = 128), and the relative risk (RR) was calculated.

RESULTS

The prevalence of apathy in post-stroke MCI was 12.9%. After 6 months, 5.2% of patients with post-stroke MCI converted to dementia. The dementia conversion rate of the apathy group was significantly higher than that of the non-apathy group before case-matching (17.2% vs 3.4%, P < 0.001), and also after case-matching (17.2% vs 6.3%, P < 0.001). Symptoms of apathy increased the risk of conversion from MCI to dementia (RR 2.75, 95% CI 1.272-5.947, P < 0.001).

CONCLUSIONS

For patients with post-stroke MCI, apathy symptoms increase the risk of conversion from MCI to dementia.

Apathy and the Risk of Predementia Syndromes in Community-Dwelling Older Adults

Objectives

Apathy is a potential predictor of dementia in older adults, but this investigation has been limited to older adults with a preexisting neurological illness like mild cognitive impairment (MCI), stroke or Parkinson’s disease. The objective of this study was to investigate the association between apathy at baseline and incident predementia syndromes, including MCI and motoric cognitive risk syndrome (MCR), subjective cognitive complaints and slow gait, in community-dwelling older adults.

Method

We prospectively studied the association between apathy (using the 3-item subscale of the Geriatric Depression Scale [GDS3A]) and incident cognitive disorders in 542 community-dwelling older adults enrolled in the Central Control of Mobility in Aging study using Cox proportional hazard models. Associations were reported as hazard ratio (HR) with 95% confidence intervals (CIs), adjusting for age, education, baseline cognitive performance, and depressive symptoms.

Results

Apathy was associated with incident MCR (HR 2.39, 95% CI: 1.10–5.20), but not predementia syndromes overall nor MCI. In sensitivity analyses of MCI subtypes, apathy was associated with nonamnestic MCI (HR 2.44, 95% CI: 1.14–5.22), but not amnestic MCI. Our study was limited by a short follow-up time (median 13.6 months; interquartile range 29.8) and a brief subscale measurement of apathy, GDS3A.

Discussion

In our study, apathy predicted MCR but not MCI in community-dwelling older adults. These results and the current literature suggest that apathy is an early risk factor for dementia. Additionally, apathy may be a novel treatment target that could forestall the disability of dementia.

Widespread white matter aberration is associated with the severity of apathy in amnestic Mild Cognitive Impairment: Tract-based spatial statistics analysis

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In aMCI, apathy severity was associated with lower FA in widespread WM pathways.

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WM aberrations are related to apathy severity after controlling for depression.

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Disruptions related to apathy severity are not limited to frontal-subcortical area.

Apathy is recognized as a prevalent behavioral symptom of amnestic Mild Cognitive Impairment (aMCI). In aMCI, apathy is associated with an increased risk and increases the risk of progression to Alzheimer’s Disease (AD). Previous DTI study in aMCI showed that apathy has been associated with white matter alterations in the cingulum, middle and inferior longitudinal fasciculus, fornix, and uncinate fasciculus. However, the underlying white matter correlates associated with apathy in aMCI are still unclear. We investigated this relationship using whole-brain diffusion tensor imaging (DTI). Twenty-nine aMCI patients and 20 matched cognitively healthy controls were included. Apathy severity was assessed using the Apathy Evaluation Scale Clinician version. We applied the tract-based spatial statistics analyses to DTI parameters: fractional anisotropy (FA), mean diffusivity, axial diffusivity, and radial diffusivity to investigate changes in white matter pathways associated with the severity of apathy. No significant difference was found in any of the DTI parameters between aMCI and the control group. In aMCI, higher severity of apathy was associated with lower FA in various white matter pathways including the left anterior part of inferior fronto-occipital fasciculus/uncinate fasciculus, genu and body of the corpus callosum, superior and anterior corona radiata, anterior thalamic radiation of both hemispheres and in the right superior longitudinal fasciculus/anterior segment of arcuate fasciculus (p < .05, TFCE-corrected) after controlling for age, gender and GDS non-apathy. A trend association was observed in the right posterior corona radiata and corticospinal tract/internal capsule, and bilateral forceps minor (p < .065, TFCE-corrected). In conclusion, in aMCI, severity of apathy is associated with aberrant white matter integrity in widely distributed pathways, within and between hemispheres.

Interactions between Personality, Depression, Anxiety and Cognition to Understand Early Stage of Alzheimer's Disease

The multifaceted nature of Alzheimer's disease (AD) and Mild cognitive impairment (MCI) can lead to wide inter-individual differences in disease manifestation in terms of brain pathology and cognition. The lack of understanding of phenotypic diversity in AD arises from a difficulty in understanding the integration of different levels of network organization (i.e. genes, neurons, synapses, anatomical regions, functions) and in inclusion of other information such as neuropsychiatric characteristics, personal history, information regarding general health or subjective cognitive complaints in a coherent model. Non-cognitive factors, such as personality traits and behavioral and psychiatric symptoms, can be informative markers of early disease stage. It is known that personality can affect cognition and behavioral symptoms. The aim of the paper is to review the different types of interactions existing between personality, depression/anxiety, and cognition and cognitive disorders at behavioral and brain/genetic levels.

Apathy in presymptomatic genetic frontotemporal dementia predicts cognitive decline and is driven by structural brain changes

Introduction

Apathy adversely affects prognosis and survival of patients with frontotemporal dementia (FTD). We test whether apathy develops in presymptomatic genetic FTD, and is associated with cognitive decline and brain atrophy.

Methods

Presymptomatic carriers of MAPT, GRN or C9orf72 mutations (N = 304), and relatives without mutations (N = 296) underwent clinical assessments and MRI at baseline, and annually for 2 years. Longitudinal changes in apathy, cognition, gray matter volumes, and their relationships were analyzed with latent growth curve modeling.

Results

Apathy severity increased over time in presymptomatic carriers, but not in non‐carriers. In presymptomatic carriers, baseline apathy predicted cognitive decline over two years, but not vice versa. Apathy progression was associated with baseline low gray matter volume in frontal and cingulate regions.

Discussion

Apathy is an early marker of FTD‐related changes and predicts a subsequent subclinical deterioration of cognition before dementia onset. Apathy may be a modifiable factor in those at risk of FTD.

Neuropsychiatric symptoms as a distinguishing factor between memory diagnoses

OBJECTIVES

To determine whether neuropsychiatric symptoms (NPS) are able to differentiate those with mild cognitive impairment (MCI) and dementia from persons who are cognitively healthy.

METHODS

Multinomial and binary logistic regressions were used to assess secondary data of a sample (n = 613) of older adults with NPS. Analyses evaluated the ability to differentiate between diagnoses, as well as the influence of these symptoms for individuals with amnestic MCI (MCI-A), non-amnestic MCI (MCI-NA), and dementia compared with those who are cognitively healthy.

RESULTS

Persons with MCI were more likely to have anxiety, apathy, and appetite changes compared with cognitively healthy individuals. Persons with dementia were more likely to have aberrant motor behaviors, anxiety, apathy, appetite changes, and delusions compared with those who were cognitively healthy. Individuals with any type of cognitive impairment were more likely to have anxiety, apathy, appetite changes, and delusions. Specifically, anxiety, apathy, appetite changes, and disinhibition were predictors of MCI-A; agitation and apathy were predictors of MCI-NA; and aberrant motor behaviors, anxiety, apathy, appetite changes, and delusions were predictors of dementia. Finally, nighttime behavior disorders were less likely in individuals with dementia.

CONCLUSIONS

The present study's results demonstrate that specific NPS are differentially represented among types of cognitive impairment and establish the predictive value for one of these cognitive impairment diagnoses.

The Roles of Apathy and Depression in Predicting Alzheimer Disease: A Longitudinal Analysis in Older Adults With Mild Cognitive Impairment

OBJECTIVE

Apathy and depression have each been associated with an increased risk of conversion from mild cognitive impairment (MCI) to Alzheimer disease (AD).These symptoms often co-occur and the contribution of each to risk of AD is not clear.

METHODS

National Alzheimer's Coordinating Center participants diagnosed with MCI at baseline and followed until development of AD or loss to follow-up (n = 4,932) were included. The risks of developing AD in MCI patients with neuropsychiatric symptoms (NPS) (apathy only, depression only, or both) were compared to that in those without NPS in a multivariate Cox regression survival analysis adjusting for baseline cognitive impairment, years of smoking, antidepressant use, and AD medication use.

RESULTS

Thirty-seven percent (N = 1713) of MCI patients developed AD (median follow-up 23 months). MCI patients with both apathy and depression had the greatest risk (hazard ratio [HR] = 1.37; 95% confidence interval [CI]: 1.17-1.61; p < 0.0001; Wald χ2 = 14.70; df = 1). Those with apathy only also had a greater risk (HR = 1.24; 95% CI: 1.05-1.47; p = 0.01; Wald χ2 = 6.22; df = 1), but not those with depression only (HR = 1.08; 95% CI: 0.95-1.22; p=0.25; Wald χ2 = 1.30; df = 1). Post-hoc analyses suggested depression may exacerbate cognitive decline in MCI patients with apathy (odds ratio = 0.70; 95% CI 0.52-0.95; p = 0.02; Wald χ2 = 5.28; df = 1), compared to those without apathy.

CONCLUSION

MCI patients with apathy alone or both apathy and depression are at a greater risk of developing AD compared to those with no NPS. Interventions targeting apathy and depression may reduce risk of AD.

The impact of apathy on cognitive performance in the elderly

OBJECTIVES

To examine the impact of apathy on cognitive performance in the elderly following the conceptual principles proposed by Marin1 and Stuss et al2 and to determine the role of the symptoms of apathy in different cognitive domains.

METHODS

Cross-sectional study with a cohort of healthy elderly subjects over 55 years old (n = 140). One hundred forty healthy-elderly subjects (aged 79.24 ± 8.6 years old) were recruited from 12 day centers in Northern Spain. Participants underwent a neuropsychological battery, which evaluated Mini Mental State Examination (MMSE), attention, processing speed, verbal fluency, visual and verbal memory, working memory, and executive functioning. Apathy was assessed by the Lille Apathy Rating Scale (LARS), which is composed of four factors: intellectual curiosity, emotion, action initiation, and self-awareness. Correlation and linear regression analyses were performed.

RESULTS

In the correlational analysis, the LARS total score correlated negatively with global cognition, verbal fluency, and visual and verbal memory. The intellectual curiosity factor correlated negatively with all cognitive domains except attention. The emotion factor correlated negatively with visual memory. No correlation was found between the action initiation and self-awareness factors or any of the cognitive variables. Multiple stepwise regression analysis showed that symptoms of apathy explained cognitive performance in attention, processing speed, verbal fluency, visual and verbal memory, working memory, executive functioning, and MMSE.

CONCLUSIONS

Apathy was significantly associated with cognitive performance, especially with the intellectual curiosity factor. Our results suggest that specific symptoms of apathy contribute differently to individual cognitive domains.

Dysexecutive disorders and their diagnosis: A position paper

Although executive function disorders are among the most prevalent cognitive impairments a consensus on diagnostic criteria has yet to be reached. With a view to harmonizing these criteria, the present position paper (i) focuses on the main dysexecutive disorders, (ii) examines recent approaches in both the behavioral and cognitive domains, (iii) defines diagnostic boundaries for frontal syndrome, (iv) reports on the frequency and profile of the executive function disorders observed in the main brain diseases, and (v) proposes an operationalization of diagnostic criteria. Future work must define the executive processes involved in human adaptive behavior, characterize their impairment in brain diseases, and improve the management of these conditions (including remediation strategies and rehabilitation).

Association of Apathy With Risk of Incident Dementia: A Systematic Review and Meta-analysis

IMPORTANCE

Fear of dementia is pervasive in older people with cognitive concerns. Much research is devoted to finding prognostic markers for dementia risk. Studies suggest apathy in older people may be prodromal to dementia and could be a relevant, easily measurable predictor of increased dementia risk. However, evidence is fragmented and methods vary greatly between studies.

OBJECTIVE

To systematically review and quantitatively synthesize the evidence for an association between apathy in dementia-free older individuals and incident dementia.

DATA SOURCES

Two reviewers conducted a systematic search of Medline, Embase, and PsychINFO databases.

STUDY SELECTION

Inclusion criteria were (1) prospective cohort studies, (2) in general populations or memory clinic patients without dementia, (3) with clear definitions of apathy and dementia, and (4) reporting on the association between apathy and incident dementia.

DATA EXTRACTION AND SYNTHESIS

PRISMA and MOOSE guidelines were followed. Data were extracted by 1 reviewer and checked by a second.

MAIN OUTCOMES AND MEASURES

Main outcomes were pooled crude risk ratios, maximally adjusted reported hazard ratios (HR), and odds ratios (OR) using DerSimonian-Laird random effects models.

RESULTS

The mean age of the study populations ranged from 69.2 to 81.9 years (median, 71.6 years) and the percentage of women ranged from 35% to 70% (median, 53%). After screening 2031 titles and abstracts, 16 studies comprising 7365 participants were included. Apathy status was available for 7299 participants. Studies included populations with subjective cognitive concerns (n = 2), mild cognitive impairment (n = 11), cognitive impairment no dementia (n = 1), or mixed cognitive and no cognitive impairment (n = 2). Apathy was present in 1470 of 7299 participants (20.1%). Follow-up ranged from 1.2 to 5.4 years. In studies using validated apathy definitions (n = 12), the combined risk ratio of dementia for patients with apathy was 1.81 (95% CI, 1.32-2.50; I2 = 76%; n = 12), the hazard ratio was 2.39 (95% CI, 1.27-4.51; I2 = 90%; n = 7), and the odds ratio was 17.14 (95% CI, 1.91-154.0; I2 = 60%; n = 2). Subgroup analyses, meta-regression, and individual study results suggested the association between apathy and dementia weakened with increasing follow-up time, age, and cognitive impairment. Meta-regression adjusting for apathy definition and follow-up time explained 95% of heterogeneity in mild cognitive impairment.

CONCLUSIONS AND RELEVANCE

Apathy was associated with an approximately 2-fold increased risk of dementia in memory clinic patients. Moderate publication bias may have inflated some of these estimates. Apathy deserves more attention as a relevant, cheap, noninvasive, and easily measureable marker of increased risk of incident dementia with high clinical relevance, particularly because these vulnerable patients may forgo health care.

Depression and Risk of Alzheimer Dementia: A Longitudinal Analysis to Determine Predictors of Increased Risk among Older Adults with Depression

OBJECTIVE

Older adults with depression are at increased risk of Alzheimer dementia, but predictors of increased risk remain incompletely understood. We aim to identify characteristics of older adults with depression most at risk of progressing to Alzheimer dementia. Identification of high-risk subgroups could facilitate future interventional strategies to reduce risk of Alzheimer dementia in older adults with depression.

METHODS

Using data from the National Alzheimer's Coordinating Center, 1,965 participants with clinically defined depression and mild cognitive impairment at baseline were followed until development of Alzheimer dementia or loss to follow-up.

RESULTS

Seven hundred and eighty (39.7%) developed Alzheimer dementia over a median follow-up duration of 27 months. In survival analyses, age (hazard ratio [HR] 1.04, 95% 1.03-1.05), baseline Mini-Mental State Exam (HR 0.85, 95% confidence interval 0.83-0.87), amnestic subtype of mild cognitive impairment (HR 1.66, 95% 1.30-2.12), presence of APOE4 allele (HR 1.99, 1.69-2.36), and presence of active depression within the last two years (HR 1.44, 95% confidence interval 1.16-1.79) were all independently associated with increased risk of Alzheimer dementia. Six hundred and fifty-six (41.7%) participants with mild cognitive impairment and active depression within the last two years developed Alzheimer dementia compared to 120 (31.6%) of those with a more remote history of depression.

CONCLUSION

Older adults with depression and mild cognitive impairment demonstrated a high rate of progression to Alzheimer dementia over a relatively short duration of follow-up. Individuals with a combination of mild cognitive impairment and recently active depression are a particularly high-risk subgroup.

Lower Choline and Myo-Inositol in Temporo-Parietal Cortex Is Associated With Apathy in Amnestic MCI

Apathy is a common symptom in patients with amnestic mild cognitive impairment (aMCI) and is associated with an increased risk of progression to Alzheimer's disease (AD). The neural substrates underlying apathy in aMCI may involve multiple brain regions, including the anterior cingulate cortex and the temporo-parietal region. Here we investigated neurometabolites in brain regions that may underlie apathy in aMCI patients using proton magnetic resonance spectroscopy (¹H-MRS). Twenty-eight aMCI patients with varying degrees of apathy and 20 matched controls underwent ¹H-MRS. Spectra were acquired from single voxels in the posterior cingulate cortex (PCC), dorsal anterior cingulate cortex (DACC), right dorsolateral prefrontal cortex (DLPFC), and right temporo-parietal cortex (TPC). Apathy was measured with the Apathy Evaluation Scale (AES). Spearman partial correlations between metabolite concentrations in each region and severity of apathy were determined. Additionally, analyses of covariance (ANCOVA) were performed to determine whether metabolite changes differed between patients with or without clinically-diagnosed apathy. The degree of apathy was found to be negatively correlated with choline and myo-inositol (mI) in the TPC. Additional exploratory analyses suggested that N-acetylaspartate (NAA)/mI ratio was reduced in aMCI without clinical apathy but not in aMCI with clinical apathy. In the DACC, glutamate and glutamine (Glx) levels tended to be higher in the aMCI with apathy group compared to controls and reduced in association with depression scores. In conclusion, apathy in aMCI patients was associated with neurometabolite changes indicative of altered membranal integrity and glial function in the right TPC. Findings also indicated that in a clinically-diagnosed aMCI cohort, apathy symptoms may be suggestive of neural changes that are distinct from aMCI without apathy.

State of the Science: Apathy As a Model for Investigating Behavioral and Psychological Symptoms in Dementia

Apathy is one of the most common and pervasive of the behavioral and psychological symptoms of dementia (BPSDs). Apathy has profound consequences for morbidity, mortality, and caregiver burden. Treatment of apathy has been hindered because of poor understanding of the mechanisms underlying this heterogeneous syndrome. Research has demonstrated that apathy is associated with disruption of the frontal-striatal system in individuals with neurodegenerative disease. As with other BPSDs, these neural mechanisms alone do not completely account for the syndrome; individual, caregiver, and environmental factors also contribute to apathy. In this article, we modify a current conceptual model of the factors contributing to BPSDs to examine determinants of apathy. This integrative model provides a more complete and theoretically informed understanding of apathy, allowing for greater insight into potential targets for research, intervention, and care. We end by proposing an agenda for moving the science of BPSDs in general, and apathy in particular, forward.

White matter change with apathy and impulsivity in frontotemporal lobar degeneration syndromes

Objective

To identify the white matter correlates of apathy and impulsivity in the major syndromes associated with frontotemporal lobar degeneration, using diffusion-weighted imaging and data from the PiPPIN (Pick's Disease and Progressive Supranuclear Palsy: Prevalence and Incidence) study. We included behavioral and language variants of frontotemporal dementia, corticobasal syndrome, and progressive supranuclear palsy.

Methods

Seventy patients and 30 controls underwent diffusion tensor imaging at 3-tesla after detailed assessment of apathy and impulsivity. We used tract-based spatial statistics of fractional anisotropy and mean diffusivity, correlating with 8 orthogonal dimensions of apathy and impulsivity derived from a principal component analysis of neuropsychological, behavioral, and questionnaire measures.

Results

Three components were associated with significant white matter tract abnormalities. Carer-rated change in everyday skills, self-care, and motivation correlated with widespread changes in dorsal frontoparietal and corticospinal tracts, while carer observations of impulsive–apathetic and challenging behaviors revealed disruption in ventral frontotemporal tracts. Objective neuropsychological tests of cognitive control, reflection impulsivity, and reward responsiveness were associated with focal changes in the right frontal lobe and presupplementary motor area. These changes were observed across clinical diagnostic groups, and were not restricted to the disorders for which diagnostic criteria include apathy and impulsivity.

Conclusion

The current study provides evidence of distinct structural network changes in white matter associated with different neurobehavioral components of apathy and impulsivity across the diverse spectrum of syndromes and pathologies associated with frontotemporal lobar degeneration.

Psychosis and dementia: risk factor, prodrome, or cause?

BACKGROUND

Progression of dementia is often associated with the emergence of neuropsychiatric symptoms (NPS), though there is recent evidence that NPS may occur in prodromal dementia (PrD) and impact clinical course. Mood and anxiety symptoms are the NPS that tend to occur most frequently in PrD and thus have been most extensively studied. Comparatively, there has been little focus on psychotic symptoms in PrD.

METHODS

The authors review the existing literature on psychosis in PrD, including the functional psychosis of early and late onset, with a focus on epidemiology, phenomenology, and clinical course and treatment considerations.

RESULTS

Patients with psychotic disorders at baseline such as schizophrenia may be more at risk for developing dementia over time, although this is not completely clear. Psychotic symptoms are likely more common in PrD than previously understood based on factor analysis studies, although they are much more common in established dementia. Variability in findings may reflect the heterogeneous nature of PrD studies to date and the lack of inclusion of patients with late onset psychosis in most clinical studies. The presence of psychosis in patients with PrD may be associated with a worse prognosis in terms of mortality and conversion to dementia.

CONCLUSIONS

Research to date suggests that psychosis in PrD may be more common than previously thought and impact clinical course negatively. Future studies incorporating patients with late onset psychotic disorders, and focusing on the impact of early recognition and treatment, are required to more fully understand the role of psychosis in PrD.

Prevalence, neurobiology, and treatments for apathy in prodromal dementia

BACKGROUND

Apathy, characterized by diminished motivation, is a highly prevalent neuropsychiatric symptom in dementia. However, there is a substantial knowledge gap with regard to prevalence rates, neurobiological underpinnings, and effective treatments for apathy in pre-dementia states, including mild cognitive impairment (MCI) and mild behavioral impairment (MBI).

METHODS

We conducted a comprehensive literature search using MEDLINE, Embase, and PsycINFO databases to identify available research on apathy in prodromal dementia.

RESULTS

Apathy has consistently been detected in individuals with MCI with varying prevalence rates, and only recently has literature discussed the prevalence of apathy in MBI. Few pharmacological treatments have been utilized for apathy, with galantamine and risperidone showing mild reductions in apathetic behaviors. Non-pharmacological interventions in prodromal dementia are beginning to be explored and show promise, but few studies have replicated those results.

DISCUSSION

More comprehensive guidelines for diagnosing apathy and further research investigating neurobiological mechanisms of apathy in MCI and MBI are required in order to effectively treat apathetic patients in prodromal dementia.

Neural correlates of apathy in late-life depression: a pilot [18 F]FDDNP positron emission tomography study

BACKGROUND

Neurotoxicity associated with amyloid and tau protein aggregation could represent a pathophysiological cascade that, along with vascular compromise, may predispose individuals to late-life depression (LLD). In LLD, apathy is common, leads to worsening of functioning, and responds poorly to antidepressant treatment. Better understanding of the pathophysiological mechanisms of apathy in LLD would facilitate development of more effective diagnostic and treatment approaches. In this cross-sectional pilot study, we performed positron emission tomography scans after injection of 2-(1-{6-[(2-[¹⁸ F]fluoroethyl)(methyl)-amino]-2-naphthyl}ethylidene) malononitrile ([¹⁸ F]FDDNP), an in vivo amyloid and tau neuroimaging study, in patients with LLD to explore neural correlates of apathy.

METHODS

Sixteen depressed elderly volunteers received clinical assessments and [¹⁸ F]FDDNP positron emission tomography scans. The cross-sectional relationship of [¹⁸ F]FDDNP binding levels with depression (Hamilton Depression Rating Scale) and apathy (Apathy Evaluation Scale) were studied using Spearman's correlation analyses because of the relatively small sample size. Age, sex, and years of education were partialed out. Significance levels were set at P ≤ 0.05.

RESULTS

[¹⁸ F]FDDNP binding in the anterior cingulate cortex was negatively associated with the Apathy Evaluation Scale total (r = -0.62, P = 0.02; where low Apathy Evaluation Scale score equals greater severity of apathy). This suggests that apathy in LLD is associated with higher amyloid and/or tau levels in the anterior cingulate cortex. None of the regional [¹⁸ F]FDDNP binding levels was significantly associated with the Hamilton Depression Rating Scale total.

CONCLUSION

This pilot study suggests that increased apathy in subjects with LLD may be associated with greater amyloid and/or tau burden in certain brain regions. Future studies in larger samples would elucidate the generalizability of these results, which eventually could lead to improved diagnostic and treatment methods in LLD.

Subjective memory complaints, mood and MCI: a follow-up study

OBJECTIVES

Subjective memory complaints (SMC) are common in older people and previous research has shown an association with mood problems, such as depression and anxiety. SMC form part of the criteria for many definitions of mild cognitive impairment (MCI), but there is controversy over whether they should be included as they may be related more strongly to mood than to objective cognitive impairment. This study aims to clarify the relationship between mood and SMC in people with MCI.

METHOD

This paper reports an analysis of data from the Medical Research Council Cognitive Function and Ageing study. Structured interviews were conducted with community-dwelling older people to assess a range of aspects of cognitive functioning and mood. Data from two time points approximately 24 months apart were used in this analysis. At baseline, participants without dementia or severe cognitive impairment were categorised into three groups according to cognitive status. Mood was investigated by assessing symptoms of anxiety and depression which were defined using a diagnostic algorithm. Associations were tested using logistic regression and chi square analyses.

RESULTS

A clear association was shown between SMC and mood, both cross-sectionally and over time. The relationship between our two competing definitions of MCI suggested that mood problems were more strongly related to the presence of SMC than objective cognitive impairment.

CONCLUSION

SMC may be a function of anxiety and depression rather than being related to objective cognitive function. This questions whether SMC should be included in definitions of MCI.

Neuropsychiatric Symptoms in Mild Cognitive Impairment

OBJECTIVE

Neuropsychiatric symptoms (NPS) may be the first manifestation of an underlying neurocognitive disorder. We undertook a review to provide an update on the epidemiology and etiological mechanisms of NPS that occur in mild cognitive impairment (MCI) and just before the onset of MCI. We discuss common clinical presentations and the implications for diagnosis and care.

METHOD

The authors conducted a selective review of the literature regarding the emergence of NPS in late life, before and after the onset of MCI. We discuss recent publications that explore the epidemiology and etiological mechanisms of NPS in the earliest clinical stages of these disorders.

RESULTS

NPS have been reported in 35% to 85% of adults with MCI and also occur in advance of cognitive decline. The occurrence of NPS for the first time in later life should increase suspicion for an underlying neurocognitive disorder. The presenting symptom may provide a clue regarding the etiology of the underlying disorder, and the co-occurrence of NPS may herald a more accelerated cognitive decline.

CONCLUSIONS

NPS are prevalent in the early clinical stages of neurocognitive disorders and can serve as both useful diagnostic and prognostic indicators. Recognition of NPS as early manifestations of neurocognitive disorders will become increasingly important as we move towards preventative strategies and disease-modifying treatments that may be most effective when deployed in the earliest stages of disease.

Different Patterns of Correlation between Grey and White Matter Integrity Account for Behavioral and Psychological Symptoms in Alzheimer's Disease

Behavioral disorders and psychological symptoms (BPSD) in Alzheimer's disease (AD) are known to correlate with grey matter (GM) atrophy and, as shown recently, also with white matter (WM) damage. WM damage and its relationship with GM atrophy are reported in AD, reinforcing the interpretation of the AD pathology in light of a disconnection syndrome. It remains uncertain whether this disconnection might account also for different BPSD observable in AD. Here, we tested the hypothesis of different patterns of association between WM damage of the corpus callosum (CC) and GM atrophy in AD patients exhibiting one of the following BPSD clusters: Mood (i.e., anxiety and depression; ADmood), Frontal (i.e., dishinibition and elation; ADfrontal), and Psychotic (delusions and hallucinations; ADpsychotic) related symptoms, as well as AD patients without BPSD. Overall, this study brings to light the strict relationship between WM alterations in different parts of the CC and GM atrophy in AD patients exhibiting BPSD, supporting the hypothesis that such symptoms are likely to be caused by characteristic patterns of neurodegeneration of WM and GM, rather than being a reactive response to accumulation of cognitive disabilities, and should therefore be regarded as potential markers of diagnostic and prognostic value in AD.

Apathy, alexithymia, and depressive symptoms: Points of convergence and divergence

This study determined convergence and divergence in the constructs of alexithymia, apathy, and depressive symptoms. Understanding of similarities and differences between these constructs will improve diagnostic accuracy for clinical and research purposes. Community-dwelling participants (N=622, M age=35.6 years, SD=13.1) completed online measures of alexithymia, depression, and apathy; 12.2% were alexithymic, 37.8% reported significant depressive symptoms, and 24.9% reported significant apathy. Exploratory Factor Analyses (EFAs) determined the best factor structure for the apathy, alexithymia, and depressive symptoms was comprised of three factors and accounted for 45.1% of item variance. The Depression, Apathy, and Alexithymia factors were defined most strongly by item content that is at the core of each construct. Depression was defined most highly by items assessing sadness, low self-esteem, and loneliness. The strongest item loadings for Alexithymia were difficulty identifying and describing feelings. Apathy was characterized by poor motivation, low interest, and lack of initiative. However, each of these core and defining features had significant cross-loadings on one of the other two factors. Negative affect shared variance with Apathy, low motivation shared variance with Depression, and difficulty describing and identify feelings shared variance with Depression and Apathy. Clinical and research implications are discussed.

Depressive symptoms increase the risk of progression to dementia in subjects with mild cognitive impairment: systematic review and meta-analysis

OBJECTIVE

There is a long-standing debate in the literature whether depressive symptoms increase the risk of dementia in older with mild cognitive impairment (MCI). We aim to conduct a meta-analysis of studies that evaluated the risk of dementia in subjects with MCI and depressive symptoms compared with subjects with MCI and no depressive symptoms.

METHODS

We calculated the relative risk of progression to dementia in subjects with MCI and depressive symptoms compared with subjects with MCI and no depressive symptoms using a generic inverse variance method with random effect models.

RESULTS

Eighteen studies were included in the meta-analysis, with a sample size of 10,861 MCI subjects. The pooled relative risk of progressing to dementia was 1.28 CI95% [1.09-1.52] (p = 0.003) in the group of MCI subjects with depressive symptoms compared with the MCI subjects with no depressive symptoms.

DISCUSSION

Our results provide additional evidence that depressive symptoms determine an additive risk effect to the progression to dementia in subjects with MCI. The comorbidity between depression and cognitive impairment can be an intervention target for prevention of dementia in MCI subjects. Copyright © 2015 John Wiley & Sons, Ltd.

Combined treatment with memantine/es-citalopram for older depressed patients with cognitive impairment: a pilot study

OBJECTIVE

The objective of the study is to assess combined antidepressant and memantine treatment in older patients presenting with depression and cognitive impairment.

METHODS

Thirty-five depressed patients with cognitive impairment participated in this open-label pilot study. We evaluated whether, over a 48-week period, combined antidepressant (primarily es-citalopram) and memantine treatment was effective in the treatment of cognitive impairment and depression. Neuropsychological testing was performed, and antidepressant response monitored at baseline and at the 12, 24, and 48-week time points.

RESULTS

Treatment with escitalopram (mean daily dose 18.62 mg, SD 5.15) and memantine (mean daily dose 13.62 mg, SD 6.67) was associated with improvement in Hamilton Depression Rating Scale scores over the 48-week study period. Patients demonstrated significant improvement in the primary outcome of cognitive performance (Selective Reminding Test total immediate recall; SRT-IR) over the 48-week treatment period (p = 0.0147). Significant improvement was also observed in measures of naming and verbal fluency but not in the other cognitive domains. One of the 35 patients (2.9%) converted to Alzheimer's disease over the 48-week treatment period. In the amnestic mild cognitive impairment subsample (n = 22), the conversion rate was 4.5%, a rate lower than in other reports of patients with DEP-CI.

CONCLUSIONS

In this open-label trial, combined antidepressant and memantine treatment in patients with DEP-CI was associated with improved cognition and a low rate of conversion to dementia compared with published studies in patients with DEP-CI. Although limited by the open-label study design that incorporates practice effects that can improve cognitive test performance, the findings suggest the need for a larger randomized placebo-controlled trial.

Obtaining Information from Family Caregivers Is Important to Detect Behavioral and Psychological Symptoms and Caregiver Burden in Subjects with Mild Cognitive Impairment

Background

The objectives of this study are to clarify the differences between the difficulties in daily life experienced by patients with both mild cognitive impairment (MCI) and chronic disease and those experienced by healthy elderly individuals.

Methods

We assessed (a) cognitive function; (b) gait ability; (c) behavioral and psychological symptoms (observed at home); (d) activities of daily living (observed at home); (e) family caregiver burden, and (f) intention to continue family caregiving of 255 cognitively normal and 103 MCI subjects attending adult day care services covered by long-term care insurance, and compared the two groups.

Results

Subjects with MCI display more behavioral and psychological symptoms than cognitively normal subjects, posing a heavy caregiver burden (p < 0.01). Behavioral and psychological symptoms most commonly observed in subjects with MCI are apathy, hallucinations, delusions, agitation, and aberrant motor behavior.

Conclusion

Information regarding the behavioral and psychological symptoms displayed at home by patients with MCI can only be obtained from family caregivers living with the patients. To provide early-stage support for elderly patients with MCI, adult day care workers should collect information from family caregivers regarding behavioral and psychological symptoms observed at home.