Depressive, functional status, and neuropsychiatric symptom trajectories before an Alzheimer's disease diagnosis

Mapping morbidity 10 years prior to a diagnosis of young onset Alzheimer's disease

INTRODUCTION

Early symptoms in young onset Alzheimer's disease (YOAD) may be misinterpreted, causing delayed diagnosis. This population-based study aimed to map morbidity prior to YOAD diagnosis.

METHODS

In a register-based incidence density matched nested case-control study, we examined hospital-diagnosed morbidity for people diagnosed with YOAD in Danish memory clinics during 2016-2020 compared to controls in a 10-year period. Conditional logistic regression produced incidence rate ratios (IRRs).

RESULTS

The study included 1745 cases and 5235 controls. YOAD patients had a higher morbidity burden in the year immediately before dementia diagnosis, for certain disorders up to 10 years before. This was especially evident for psychiatric morbidity with the highest increased IRRs throughout the entire period and IRR 1.43 (95% confidence interval 1.14-1.79) in the 5-10-years before dementia diagnosis.

DISCUSSION

YOAD patients display a different pattern of morbidity up to 10 years prior to diagnosis. Awareness of specific alterations in morbidity may improve efforts toward a timely diagnosis.

HIGHLIGHTS

Retrospective, nested case-control study of young onset Alzheimer's disease (YOAD). YOAD cases had a higher morbidity burden than controls. YOAD cases had a higher psychiatric morbidity burden up to 10 years before diagnosis. Altered morbidity patterns could serve as an early warning sign of YOAD.

Distinguishing features of depression in dementia from primary psychiatric disease

Depression is a common and devastating neuropsychiatric symptom in the elderly and in patients with dementia. In particular, nearly 80% of patients with Alzheimer's Disease dementia experience depression during disease development and progression. However, it is unknown whether the depression in patients with dementia shares the same molecular mechanisms as depression presenting as primary psychiatric disease or occurs and persists through alternative mechanisms. In this review, we discuss how the clinical presentation and treatment differ between depression in dementia and as a primary psychiatric disease, with a focus on major depressive disorder. Then, we hypothesize several molecular mechanisms that may be unique to depression in dementia such as neuropathological changes, inflammation, and vascular events. Finally, we discuss existing issues and future directions for investigation and treatment of depression in dementia.

Difficulty with Taking Medications Is Associated with Future Diagnosis of Alzheimer's Disease and Related Dementias

BACKGROUND

Medication management requires complex cognitive functioning, and therefore, difficulty taking medications might be an early sign of cognitive impairment and could be a risk factor for Alzheimer's disease and related dementias (ADRD). Accordingly, people with difficulty taking medications may benefit from more detailed cognitive screening, potentially aiding in the diagnosis of ADRD, which is underdiagnosed. We are unaware of evidence on medication management difficulties that precede a real-world ADRD diagnosis in the USA.

OBJECTIVE

Examine the association between difficulty taking medications and subsequent real-world ADRD diagnoses.

DESIGN

Case-control study, using Health and Retirement Study (HRS) survey data linked to Medicare claims.

PARTICIPANTS

A total of 1461 HRS respondents with an ADRD diagnosis observed from 1993 to 2012 (cases), matched by year of birth, wave of HRS entry, and sex to 3771 controls with no ADRD diagnosis.

MAIN MEASURES

We examined the association between diagnosis of ADRD and self-reported difficulty taking medications in the preceding years (1-2 and 3-4 years prior to case definition). Control individuals were assigned the index date from their matched case. Conditional logistic regressions adjusted for age, sex, race, education, and comorbidities.

KEY RESULTS

Compared with matched controls, cases had higher prevalence of difficulty taking medications 1-2 years prior to diagnosis (11.0% versus 2.3%), and 3-4 years prior to diagnosis (5.8% versus 2.3%). Adjusted analyses showed that compared with individuals without ADRD, those with an ADRD diagnosis had more than four times higher odds of difficulty taking medications 1-2 years prior (OR = 4.56 (CI 3.30-6.31)), and more than two times higher odds of difficulty taking medications 3-4 years prior (OR = 2.41 (CI 1.61-3.59)).

CONCLUSIONS

Odds of medication difficulty 1-2 years prior were more than four times greater for individuals with ADRD diagnoses compared with those without ADRD. Medication management difficulties may prompt further cognitive screening, potentially aiding in earlier recognition of ADRD.

Depression in Alzheimer's Disease: An Alternative Role for Selective Serotonin Reuptake Inhibitors?

Depression is a common co-morbidity seen in people with Alzheimer's disease (AD). However, the successful treatment of depressive symptoms in people with AD is rarely seen. In fact, multiple randomized controlled trials have shown selective serotonin reuptake inhibitors (SSRIs), the current best recommended treatment for depression, to be ineffective in treating depressive symptoms in people with AD. One explanation for this lack of treatment effect may be that depressive symptoms can reflect the progression of AD, rather than clinical depression and are a consequence of more severe neurodegeneration. This raises several questions regarding not only the efficacy of SSRIs in the treatment of depression in people with AD but also regarding the accuracy of diagnosis of depression in AD. However, there may be a rationale for the prescription of SSRIs in early AD. Even in the absence of depression, SSRIs have been shown to slow the conversion from mild cognitive impairment to AD. This may be attributed to the effect of SSRIs on the processing of amyloid-β precursor protein, which may cause a reduction in the accumulation of amyloid-β. Thus, although SSRIs may lack efficacy in treating depression in people with AD, they may hold therapeutic potential for treating and delaying the progression of AD especially if treatment begins in the early stages of AD. This article reviews the current consensus for SSRI treatment of depression in people with AD and highlights the possibility of SSRIs being a treatment option for delaying the progression of AD.

Association of Low-Level Ozone with Cognitive Decline in Older Adults

Increasing evidence points to an association of airborne pollutant exposure with respiratory, cardiovascular, and neurological pathology. We examined whether or not ground-level ozone or fine particulate matter ≤ 2.5 μm in diameter (PM2.5) was associated with accelerated cognitive decline. Using repeated measures mixed regression modeling, we analyzed cognitive performance of a geographically diverse sampling of individuals from the National Alzheimer's Coordinating Center between 2004-2008. Ambient air concentrations of ozone and PM2.5 were established using a space-time Hierarchical Bayesian Model that statistically merged air monitor data and modeled air quality estimates. We then compared the ambient regional concentrations of ozone and PM2.5 with the rate of cognitive decline in residents within those regions. Increased levels of ozone correlated with an increased rate of cognitive decline, following adjustment for key individual and community-level risk factors. Furthermore, individuals harboring one or more APOE4 alleles exhibited a faster rate of cognitive decline. The deleterious association of ozone was confined to individuals with normal cognition who eventually became cognitively impaired as opposed to those who entered the study with baseline impairment. In contrast to ozone, we did not observe any correlation between ambient PM2.5 and cognitive decline at regulatory limits set by the Environmental Protection Agency. Our findings suggest that prolonged exposure to ground-level ozone may accelerate cognitive decline during the initial stages of dementia development.

Are depressive symptoms in mild cognitive impairment predictive of conversion to dementia?

BACKGROUND

Depressive symptoms are common in amnestic mild cognitive impairment (aMCI). The association between depressive symptoms and conversion to dementia is not yet clear. This longitudinal study was conducted to ascertain whether depressive symptoms in aMCI patients are predictive of conversion to dementia.

METHODS

35 aMCI patients participated in this study. All participants underwent cognitive testing and were administered the geriatric depression scale (GDS) to determine the presence of depressive symptoms. A score equaling or higher than 11 on the GDS was taken as the cut-off point for presence of significant depressive symptoms. Conversion to dementia was assessed at follow-up visits after 1.5, 4, and 10 years.

RESULTS

31.4% of the patients reported depressive symptoms at baseline. None of the cognitive measures revealed a significant difference at baseline between patients with and without depressive symptoms. After 1.5, 4, and 10 years respectively 6, 14, and 23 patients had converted to dementia. Although the GDS scores at baseline did not predict conversion to dementia, the cognitive measures and more specifically a verbal cued recall task (the memory impairment scale-plus) was a good predictor for conversion.

CONCLUSIONS

Based on this dataset, the presence of depressive symptoms in aMCI patients is not predictive of conversion to dementia.

Medicare Utilization and Expenditures Around Incident Dementia in a Multiethnic Cohort

BACKGROUND

Few studies have examined patterns of health care utilization and costs during the period around incident dementia.

METHODS

Participants were drawn from the Washington Heights-Inwood Columbia Aging Project, a multiethnic, population-based, prospective study of cognitive aging of Medicare beneficiaries in a geographically defined area of northern Manhattan. Medicare utilization and expenditure were examined in individuals with clinically diagnosed dementia from 2 years before until 2 years after the initial diagnosis. A sample of non-demented individuals who were matched on socio-demographic and clinical characteristics at study enrollment was used as controls. Multivariable regression analysis estimated effects on Medicare utilization and expenditures associated with incident dementia.

RESULTS

During the 2 years before incident dementia, rates of inpatient admissions and outpatient visits were similar between dementia patients and non-demented controls, but use of home health and skilled nursing care and durable medical equipment were already higher in dementia patients. Results showed a small but significant excess increase associated with incident dementia in inpatient admissions but not in other areas of care. In the 2 years before incident dementia, total Medicare expenditures were already higher in dementia patients than in non-demented controls. But we found no excess increases in Medicare expenditures associated with incident dementia.

CONCLUSIONS

Demand for medical care already is increasing and costs are higher at the time of incident dementia. There was a small but significant excess risk of inpatient admission associated with incident dementia.

Depressive symptomatology in severe dementia in a European sample: prevalence, associated factors and prescription rate of antidepressants

BACKGROUND

Depression is a common comorbid disorder of dementia. This study explores the prevalence of and factors associated with depressive symptomatology, and antidepressant prescription rates in severe dementia across eight European countries.

METHODS

In total, 414 people with severe dementia completed measures of cognition and quality of life (QoL), whilst carers completed proxy measures of activities of daily living (ADLs), depression, neuropsychiatric symptoms, QoL and comorbidity.

RESULTS

Findings indicated that 30% of the sample had depression, whilst the highest and lowest prevalence of depression was reported in Germany and Finland, respectively. Lower QoL, the presence of pain and more frequent neuropsychiatric symptoms were associated with depressive symptomatology, whilst no significant relationship between impairment of ADLs, comorbidity, and depression emerged. Spain and Estonia had the highest and lowest rates of antidepressant prescribing, respectively, whilst Germany had the highest discrepancy between depressive symptomatology and prescription.

CONCLUSIONS

The study highlights variations across countries in the prevalence of depressive symptomatology in severe dementia and prescription of antidepressants. Information about factors associated with depressive symptomatology may help to better identify and manage depression.

Depression versus dementia: is this construct still relevant?

Cognitive impairment has long been identified as a component of late-life depression (LLD), and depressive symptoms are common in neurodegeneration. Depression may confer a greater risk of cognitive decline in a cognitively intact population and further cognitive decline in a mild cognitive impairment population compared with those without depression. Exploration of the link between cognitive impairment in LLD and the depressive features of neurodegeneration is an essential part of a diagnostic algorithm. In this review, we will discuss these links; we will address depressive symptoms as a risk factor for dementia and as a prodrome to dementia. We will review clinical subtypes and imaging markers as predictors of development of dementia in depressed patients and explore vascular etiologies. We will also explore LLD and dementia as a spectrum, rather than mutually exclusive diagnostic entities.