Amyloid Plaques and Symptoms of Depression Links to Medical Help-Seeking due to Subjective Cognitive Decline

Depressive Symptoms Are Not Associated with Predementia Cerebrospinal Fluid Amyloid Pathology

Introduction

Depressive symptoms are associated with Alzheimer's disease (AD), but their neurobiological and neuropsychological correlates remain poorly understood. We investigate if depressive symptoms are associated with amyloid (Aβ) pathology and cognition in predementia AD.

Methods

We included subjective cognitive decline (SCD, n = 160) and mild cognitive impairment (MCI, n = 192) from the dementia disease initiation cohort. Depressive symptoms were assessed using the Geriatric Depression Scale (GDS-15). Aβ pathology was determined using cerebrospinal fluid (CSF) Aβ42/40 ratio. Associations between depressive symptoms and cognition were assessed with logistic regression.

Results

Only the Aβ negative MCI group (MCI-Aβ-) was associated with depressive symptoms (odds ratio [OR] = 2.65, p = 0.005). Depressive symptoms were associated with worse memory in MCI-Aβ- (OR = 0.94, p = 0.039), but with better performance in MCI-Aβ+ (OR = 1.103, p = 0.001).

Conclusion

Our results suggest that depressive symptoms in MCI are neither associated with Aβ pathology, nor AD-associated memory impairment. However, memory impairment in non-AD MCI may relate to depressive symptoms.

Neurobiological correlation between phosphorylated tau and mood symptoms in memory clinic patients

BACKGROUND

Alzheimer's disease (AD) dementia and mild cognitive impairment are characterised by impaired cognition accompanied by neuropsychiatric symptoms (NPS) relating to mood, including depression, anxiety, and apathy. However, the utility of AD biomarkers for predicting mood symptoms of NPS remains controversial. Herein, we analyzed the relationship between phosphorylated tau (p-tau) and depression, anxiety, and apathy of NPS. We also examined the influence of genetic factors such as apolipoprotein E (APOE) ε4 on these relationships.

METHODS

We conducted a cross-sectional survey in older patients (n = 122) with normal cognition (n = 12), mild cognitive impairment (n = 46), and AD (n = 64) strictly diagnosed by the board of psychiatrists and neurologists of Hokkaido University. NPS of the patients were assessed using the Neuropsychiatric Inventory Questionnaire (NPI). All patients also received a lumbar puncture to obtain cerebral spinal fluid for assessment of p-tau. The inverse probability weighting method was used to adjust for demographic differences between the p-tau present group and the p-tau absent group.

RESULTS

There was an association between p-tau accumulation and decreased incidence of depression and apathy. APOE ε4 non-carriers also showed a trend toward a negative association between p-tau and depression, which was not evident in APOE ε4 carriers.

CONCLUSIONS

We provide new evidence for a negative correlation between p-tau and depression and apathy of NPS, which may be influenced by APOE ε4. Future longitudinal studies are required to confirm the utility of p-tau for predicting the course of mood symptoms in patients with cognitive decline.

Characteristics of subjective cognitive decline associated with amyloid positivity

INTRODUCTION

The evidence for characteristics of persons with subjective cognitive decline (SCD) associated with amyloid positivity is limited.

METHODS

In 1640 persons with SCD from 20 Amyloid Biomarker Study cohort, we investigated the associations of SCD-specific characteristics (informant confirmation, domain-specific complaints, concerns, feelings of worse performance) demographics, setting, apolipoprotein E gene (APOE) ε4 carriership, and neuropsychiatric symptoms with amyloid positivity.

RESULTS

Between cohorts, amyloid positivity in 70-year-olds varied from 10% to 76%. Only older age, clinical setting, and APOE ε4 carriership showed univariate associations with increased amyloid positivity. After adjusting for these, lower education was also associated with increased amyloid positivity. Only within a research setting, informant-confirmed complaints, memory complaints, attention/concentration complaints, and no depressive symptoms were associated with increased amyloid positivity. Feelings of worse performance were associated with less amyloid positivity at younger ages and more at older ages.

DISCUSSION

Next to age, setting, and APOE ε4 carriership, SCD-specific characteristics may facilitate the identification of amyloid-positive individuals.

Prevalence of Depressive Symptoms in a Memory Clinic Cohort: A Retrospective Study

BACKGROUND

Depression has been suggested to be a cause of reversible cognitive impairment but also a risk factor for neurodegenerative disease. Studies suggest that depression prevalence may be high in early onset dementia, particularly Alzheimer's disease, but this has not been systematically assessed in a biomarker-validated clinical dementia cohort to date.

OBJECTIVE

To examine the prevalence, features, and association with amyloid pathology of lifetime depressive symptoms in a memory clinic cohort meeting appropriate use criteria for amyloid PET imaging.

METHODS

We included 300 patients from a single-center memory clinic cohort that received diagnostic biomarker evaluation with amyloid PET imaging according to appropriate use criteria. History of lifetime depressive symptoms was retrospectively assessed through structured review of clinical correspondence.

RESULTS

One hundred forty-two (47%) patients had a history of significant depressive symptoms ('D+'). Of these, 89% had ongoing symptoms and 60% were on antidepressants at the time of presentation to our Clinic. Depressive symptoms were equally highly prevalent in the amyloid-positive and the heterogeneous group of amyloid-negative patients.

CONCLUSION

Approximately half of patients who meet appropriate use criteria for amyloid PET had a history of depressive symptoms. We suggest that depression is an important feature of both neurodegenerative and non-neurodegenerative cognitive impairment and may contribute to the diagnostic uncertainty behind referral to amyloid PET.

Longitudinal Trajectories of Participant- and Study Partner-Rated Cognitive Decline, in Relation to Alzheimer's Disease Biomarkers and Mood Symptoms

Whereas discrepancies between participant- and study partner-reported cognitive concerns on the Alzheimer's disease (AD) continuum have been observed, more needs to be known regarding the longitudinal trajectories of participant- vs. study partner-reported concerns, particularly their relationship to AD biomarkers and mood symptomology. Additionally, it is unclear whether years of in-clinic data collection are needed to observe relationships with AD biomarkers, or whether more frequent, remote assessments over shorter periods of time would suffice. This study primarily sought to examine the relationships between longitudinal trajectories of participant- and study partner-rated cognitive decline and baseline biomarker levels [i.e., amyloid and tau positron emission tomography (PET)], in addition to how mood symptomatology may alter these trajectories of concerns over a 2-year period. Baseline mood was associated with longitudinal participant-rated concerns, such that participants with elevated depression and anxiety scores at baseline had decreasing concerns about cognitive decline over time (fixed estimate = -0.17, 95% CI [-0.29 to -0.05], t = -2.75, df = 457, adj. p = 0.012). A significant interaction between baseline amyloid (fixed estimate = 4.07, 95% CI [1.13-7.01], t = 2.72, df = 353, adj. p = 0.026) and tau (fixed estimate = 3.50, 95% CI [0.95-6.06], t = 2.70, df = 331, adj. p = 0.030) levels was associated with increasing study partner concerns, but not participant concerns, over time. The interaction between amyloid and study partner concerns remained significant when utilizing only the first year of concern-related data collection. Overall, these results suggest that frequent, remote assessment of study partner-reported concerns may offer additional insight into the AD clinical spectrum, as study partners appear to more accurately update their concerns over time with regard to pathology, with these concerns less influenced by participants' mood symptomatology.

Age and gender disparities in depression and subjective cognitive decline-related outcomes

OBJECTIVES

Determine the association between depression and SCD-related outcomes by age and gender.

METHODS

Using 2018 Behavioral Risk Factor Surveillance System survey data, crude and multivariable logistic regression models were used to determine the associations between depression and SCD-related outcomes by age and gender.

RESULTS

Among respondents 45 to 69, depression was associated with SCD [adjusted OR (aOR): 4.36; 95% CI: 3.24-5.86]; needing assistance with activities due to confusion/memory loss (aOR: 2.38; 95% CI: 1.26 - 4.51); needing help with activities and the help is not available (aOR: 4.46; 95% CI: 1.31 - 15.2); and having discussed confusion/memory loss with a health care professional (aOR: 1.87; 95% CI: 1.09 - 3.23). However, among respondents 70 and older, depression was associated with SCD (aOR): 3.52; 95% CI: 2.06-6.02); needing help with activities and the help is not available (aOR: 0.09; 95% CI: 0.01-0.56); confusion/memory loss interfering with work/social activities (aOR: 2.44; 95% CI: 1.03-5.79); and having discussed confusion/memory loss with a health care professional (aOR): 2.99; 95% CI: 1.20-7.40). Depression was positively associated with SCD among men (aOR): 3.68; 95% CI: 2.52-5.38) and women (aOR): 4.76; 95% CI: 3.29-6.87; and was positively associated with all SCD-related outcomes among men except for confusion/memory loss interfering with work/social activities and given up chores. Depression was positively associated with the latter among women (aOR): 2.10; 95% CI: 1.09-4.06).

DISCUSSION

SCD interventions should include assessment of and intervention for depression, and consider age and gender differences.

CCCDTD5: Clinical role of neuroimaging and liquid biomarkers in patients with cognitive impairment

Since 1989, four Canadian Consensus Conferences on the Diagnosis and Treatment of Dementia (CCCDTDs) have provided evidence-based dementia diagnostic and treatment guidelines for Canadian clinicians and researchers. We present the results from the Neuroimaging and Fluid Biomarkers Group of the 5th CCCDTD (CCCDTD5), which addressed topics chosen by the steering committee to reflect advances in the field and build on our previous guidelines. Recommendations on Imaging and Fluid Biomarker Use from this Conference cover a series of different fields. Prior structural imaging recommendations for both computerized tomography (CT) and magnetic resonance imaging (MRI) remain largely unchanged, but MRI is now more central to the evaluation than before, with suggested sequences described here. The use of visual rating scales for both atrophy and white matter anomalies is now included in our recommendations. Molecular imaging with [18F]-fluorodeoxyglucose ([18F]-FDG) Positron Emisson Tomography (PET) or [99mTc]-hexamethylpropyleneamine oxime/ethylene cysteinate dimer ([99mTc]-HMPAO/ECD) Single Photon Emission Tomography (SPECT), should now decidedly favor PET. The value of [18F]-FDG PET in the assessment of neurodegenerative conditions has been established with greater certainty since the previous conference, and it has now been recognized as a useful biomarker to establish the presence of neurodegeneration by a number of professional organizations around the world. Furthermore, the role of amyloid PET has been clarified and our recommendations follow those from other groups in multiple countries. SPECT with [123I]-ioflupane (DaTscanTM) is now included as a useful study in differentiating Alzheimer's disease (AD) from Lewy body disease. Finally, liquid biomarkers are in a rapid phase of development and, could lead to a revolution in the assessment AD and other neurodegenerative conditions at a reasonable cost. We hope these guidelines will be useful for clinicians, researchers, policy makers, and the lay public, to inform a current and evidence-based approach to the use of neuroimaging and liquid biomarkers in clinical dementia evaluation and management.

Structural imaging outcomes in subjective cognitive decline: Community vs. clinical-based samples

Subjective cognitive decline (SCD) has been proposed as a preclinical stage of Alzheimer's disease (AD). Neuroimaging studies have suggested early AD-like structural brain alterations in SCD subjects compared to healthy controls. However, there is substantial heterogeneity in the results, which might depend on whether SCD samples were drawn from the community or from memory clinics. Here we reviewed brain atrophy, assessed through structural magnetic resonance imaging, separately for SCD-community and clinic-based samples. SCD-community samples show a more consistent pattern of atrophy, involving the hippocampus and temporal and parietal cortices. Similarly, in SCD-clinic samples the temporo-parietal cortex showed early vulnerability, however these studies reported a more heterogeneous atrophy pattern. Overall, these studies suggest both commonalities and differences in brain atrophy patterns between SCD clinical and community samples. In SCD-community, the temporal cortex is involved, while SCD-clinical exhibited a more complex pattern of atrophy, which may be related to a more heterogeneous sample reporting neuropsychiatric symptoms along with preclinical AD.