Cognitive functioning and the natural course of depressive symptoms in late life

Determinants of Psychomotor Slowing in Older Adults With Depressive Disorder

BACKGROUND

Psychomotor slowing in older adults with depressive disorder (DD) has been associated with a poor prognosis. Whether psychomotor slowing is associated with depression itself, age-related physical and cognitive factors, or both, is important to personalize treatments. We examined the unique contributions of different determinants of psychomotor slowing in older adults with DD.

METHODS

Baseline data of the Routine-Outcome-Monitoring for Geriatric Psychiatry and Science (ROM-GPS) study, and the Netherlands Study of Depression in Older persons (NESDO) were used to include a total of N = 521 patients (N = 143 ROM-GPS; N = 378 NESDO) aged ≥ 60 years who fulfilled DSM-criteria of a DD. Psychomotor slowing was measured multidimensionally with motor slowing (gait speed), cognitive slowing (processing speed), and subjective slowing (item-23 of Inventory-of-Depressive-Symptoms scale). Potential determinants were categorized into demographics, depression-related, physical and cognitive health, lifestyle, and psychosocial factors. Multivariate linear regression analyses were applied for each component of slowing.

RESULTS

The minority (7.3%) had slowing on all three components. Moderate correlations were found between motor and cognitive slowing, whereas no or low correlations were found between subjective slowing and either motor or cognitive slowing. Motor slowing was associated with higher age, female sex, polypharmacy, and higher body-mass-index. Cognitive slowing was associated with diminished global cognitive performance. Subjective slowing with higher depression severity and worse global cognitive performance.

CONCLUSIONS

Psychomotor slowing in older adults with DD is complex, consisting of a motor, cognitive, and subjective component, all of which have a unique phenotype. Because motor and cognitive slowing are not closely related to depression severity, it suggests that in older people with DD other age-related factors are more important determinants, which should be taken into account for optimizing treatment.

Exploring the Reciprocal Relationship between Depressive Symptoms and Cognitive Function among Chinese Older Adults

(1) Objectives: This study aims to investigate the bidirectional relationship between depressive symptoms and cognitive function among older adults in China, addressing a research gap in the context of developing nations. (2) Methods: A total of 3813 adults aged 60 and older participating in 2013, 2015, and 2018 waves of the China Health and Retirement Longitudinal Study (CHARLS) were included. A fixed-effects model and cross-lagged panel model (CLPM) was utilized. (3) Results: First, the results indicated that a significant negative correlation existed between depressive symptoms and cognitive function in older adults during the study period (β = -0.084, p < 0.001). Second, after controlling for unobserved confounding factors, the deterioration and improvement of depressive symptoms still significantly affected cognitive function (β = -0.055, p < 0.001). Third, using the cross-lagged panel model, we observed a reciprocal relationship between depressive symptoms (Dep) and cognitive function (Cog) among Chinese older adults (Dep2013 → Cog2015, β = -0.025, p < 0.01; Dep2015 → Cog2018, β = -0.028, p < 0.001; Cog2013 → Dep2015, β = -0.079, p < 0.01; Cog2015 → Dep2018, β = -0.085, p < 0.01). (4) Discussion: The reciprocal relationship between depressive symptoms and cognitive functioning in older adults emphasizes the need for integrated public health policies and clinical interventions, to develop comprehensive intervention strategies that simultaneously address depressive symptoms and cognitive decline.

Quantitative readability analysis of websites providing information on traumatic brain injury and epilepsy: A need for clear communication

OBJECTIVE

The use of the Internet for health-related questions is increasing, but it is not clear whether individuals can understand the information available online. Most health organizations recommend that health educational materials (HEMs) be written below the sixth grade reading level. This study was designed to evaluate the readability level of available online HEMs pertaining to traumatic brain injury (TBI), epilepsy, and posttraumatic epilepsy (PTE).

METHODS

This cross-sectional readability assessment included HEMs from TBI and epilepsy stakeholder organizations and those obtained from four Internet searches. The search strategy was designed to replicate a nonmedical individual's keyword searches. Each HEM was assessed with an online automated readability tool using three indices (Flesch Reading Ease Score, Flesch-Kincaid Grade Level, and Simple Measure of Gobbledygook). Findings were compared as a function of organization type (journalistic news or health organization), targeted medical condition (TBI, epilepsy, or PTE), or content topic (patient health education, clinical research education, or both).

RESULTS

Readability analysis of 405 identified HEMs revealed scores above the sixth grade reading level recommendation. Only 6.2% of individual HEMs met the sixth grade recommendation. Journalistic news organizations' HEMs had similar readability levels to health organizations' HEMs. PTE-related HEMs required the highest readability level, >11th grade (P < .001). There were significant differences in the readability scores (P < .01 for all indices) among HEMs with information on health education, research education, or both topics. The highest required readability level (>12 grade level) was for HEMs that included both health and research education.

SIGNIFICANCE

The majority of TBI-, epilepsy-, and PTE-related online HEMs do not meet the sixth grade reading recommendation. Improving the readability of HEMs may advance health literacy around TBI, epilepsy, and PTE, leading to more effective participant recruitment/retention strategies for future antiepileptogenesis trials in persons with TBI and perhaps better patient-centered outcomes.

Illness and intelligence are comparatively strong predictors of individual differences in depressive symptoms following middle age

OBJECTIVE

We compared the importance of socio-demographic, lifestyle, health, and multiple cognitive measures for predicting individual differences in depressive symptoms in later adulthood.

METHOD

Data came from 6203 community-dwelling older adults (age 41-93 years at study entry) from the United Kingdom. Predictors (36 in total) were assessed up to four times across a period of approximately 12 years. Depressive symptoms were measured with the Geriatric Depression Scale. Statistical methods included multiple imputation (for missing data), random forest analysis (a machine learning approach), and multivariate regression.

RESULTS

On average, depressive symptoms increased gradually following middle age and appeared to accelerate in later life. Individual differences in depressive symptoms were most strongly associated with differences in combined symptoms of physical illness (positive relation) and fluid intelligence (negative relation). The strength of association between depressive symptoms and fluid intelligence was unaffected by differences in health status within a subsample of chronically depressed individuals.

CONCLUSION

Joint consideration of general health status and fluid intelligence may facilitate prediction of depressive symptoms severity during later life and may also serve to identify sub-populations of community-dwelling elders at risk for chronic depression.

Cognitive performance in antidepressant-free recurrent major depressive disorder

BACKGROUND

Cognitive complaints are common in depression, and cognition may be an important treatment target as cognitive problems often remain during remission and may contribute to recurrence risk. Previous studies of cognitive performance in depression have mainly examined late-life depression, with a focus on older adults, or assessed performance in specific cognitive tasks rather than cognitive domains.

METHODS

This study examined cognitive performance across multiple cognitive domains in antidepressant-free depressed adults with early onset recurrent depression compared to never-depressed controls. Domain scores were calculated for episodic memory, executive function, processing speed, and working memory, and the effect of depression diagnosis, depression severity, and depression duration on each domain score was examined, including interactions with age, sex, and education.

RESULTS

Currently depressed adults (n = 91) exhibited poorer performance in the processing speed domain compared with never-depressed adults (n = 105). Additionally, there was an interactive effect of depression duration and age on processing speed and executive function domain performance, such that performance was worse with older age and longer duration of depression. There were no effects of depression severity on performance across the cognitive domains.

CONCLUSIONS

These findings support that processing speed deficits appear in young adults with early onset depression that may not be related to current mood. Additionally, the effects of cumulative depressive episodes may interact with aging such that cognitive performance deficits worsen with recurrence over the lifespan.

Is the naturalistic course of depression in older people related to received support over time? Results from a longitudinal population-based study

OBJECTIVES

To test the interrelation of the naturalistic course of depression in older people with long-term support received.

DESIGN

Longitudinal cohort study.

METHODS

A sample of 277 adults age 55-85 years participating in the Longitudinal Aging Study Amsterdam, with clinically relevant depressive symptoms at baseline (scores ≥16 on the Center for Epidemiological Studies Depression Scale) were followed up over a period of 13 years. General estimating equations were used to examine the relation between depression course and emotional/instrumental support received over time. In addition, partner status, gender, and age were tested as modifiers.

RESULTS

A 2-way interaction between depression courses types and time showed significant differences in instrumental support received over time in older people with a late-life depression. Three-way interactions showed that associations between depression course and support variables were modified by gender and partner status.

CONCLUSION

Both men and singles, with a chronic course of depression may be at risk to lose emotional and instrumental support over time. Professional attention is needed to prevent a chronic course of late-life depression, and to preserve personal social networks. Copyright © 2016 John Wiley & Sons, Ltd.

Older Adults' Perspectives on Clinical Research: A Focus Group and Survey Study

OBJECTIVES

Clinical trials can benefit from patient perspectives to inform trial design, such as choice of outcome measures. We engaged older adults in focus groups and surveys to get their perspective regarding needs in clinical research. The goal was to inform the development of a new clinical trial of medication strategies for treatment-resistant depression in older adults.

METHODS

Older adults with depression participated in focus groups and a subsequent survey in St. Louis and New York. They were queried regarding research design features including outcomes, clinical management, mobile technology and iPad-administered assessments, the collection of DNA, and the receipt of their personal results.

RESULTS

Patients told us: (1) psychological well-being and symptomatic remission are outcomes that matter to them; (2) it is important to measure not only benefits but risks (such as risk of falling) of medications; (3) for pragmatic trials in clinical settings, the research team should provide support to clinicians to ensure that medications are properly prescribed; (4) technology-based assessments are acceptable but there were concerns about data security and burden; (5) DNA testing is very important if it could improve precision care; (6) participants want to receive aggregate findings and their own personal results at the end of the study.

CONCLUSIONS

Patients gave useful and wide-ranging guidance regarding clinical and comparative effectiveness research in older adults. We discuss these findings with the goal of making the next generation of geriatric studies more impactful and patient-centered.

The Longitudinal Aging Study Amsterdam: cohort update 2016 and major findings

The Longitudinal Aging Study Amsterdam (LASA) is an ongoing longitudinal study of older adults in the Netherlands, which started in 1992. LASA is focused on the determinants, trajectories and consequences of physical, cognitive, emotional and social functioning. The study is based on a nationally representative sample of older adults aged 55 years and over. The findings of the LASA study have been reported in over 450 publications so far (see www.lasa-vu.nl ). In this article we describe the background and the design of the LASA study, and provide an update of the methods. In addition, we provide a summary of the major findings from the period 2011-2015.

Cognitive functioning throughout the treatment history of clinical late-life depression

OBJECTIVE

Previous investigations into the relationship between late-life depressive symptoms and cognitive functioning have resulted in mixed findings concerning whether or not depressive symptoms and cognitive functioning are related. The mixed reports may be due in part to differences in clinical and nonclinical samples and to inadequate consideration of the dynamic nature (i.e., fluctuating course) of depressive symptoms and cognitive functioning in older adults. The current study examined the chronic, acute, and longitudinal relationships between depressive symptoms and cognitive functioning in older adults in an ongoing treatment study of major depressive disorder (MDD).

METHODS

The neurocognitive outcomes of depression in the elderly study operates in a naturalistic treatment milieu using a pharmacological treatment algorithm and regular psychiatric assessment. Four hundred and fifty-three older adults [mean age 70 years, standard deviation (SD) = 7.2] meeting criteria for MDD at study enrollment received annual neuropsychological testing and depressive symptom monitoring for an average of 8.5 years (SD = 4.5).

RESULTS

Hierarchical linear modeling revealed that higher age, lower education, and higher average/chronic levels of depressive symptoms were related to lower cognitive functioning. Additionally, results revealed that when an individual's depressive symptoms are higher than is typical for a specific individual, general cognitive function was worse than average. There was no evidence of lagged/longitudinal relationships between depressive symptoms and cognitive functioning in older adults in treatment for MDD.

CONCLUSIONS

Cognitive functioning and depressive symptoms are concurrently associated in older adults with MDD, highlighting the potential importance for stabilizing mood symptoms as a means to manage cognitive deficits in late-life depression.

Cognitive performance and the course of depressive symptoms over 7 years of follow-up: the SMART-MR study

BACKGROUND

Depressive symptoms and cognitive impairment often co-occur, but their interactive relationship is complex and the direction of causation is still a topic of research. We examined the influence of cognitive performance on the course of depressive symptoms during 7 years of follow-up in patients with vascular disease.

METHOD

Within the SMART-MR study, 736 patients (mean age 62 ± 10 years) had neuropsychological assessment on four cognitive domains at baseline [memory (MEM), working memory (WMEM), executive functioning (EXEC), and information processing speed (SPEED)]. Depressive symptoms were assessed with the Patient Health Questionnaire-9 (PHQ-9) at baseline and every 6 months during 7 years of follow-up. Generalized Estimating Equation (GEE) models were used to assess the association between cognitive performance with depressive symptoms at multiple time points during follow-up. Interaction terms between the respective cognitive domains and time was included to examine if the course of depressive symptoms differed according to baseline cognitive performance.

RESULTS

The GEE analyses showed no significant interactions between the respective cognitive domains and time indicating no different course of depressive symptoms according to baseline cognitive performance. Lower MEM, EXEC or SPEED, but not WMEM performance, was significantly associated with more depressive symptoms during follow-up per z score decrease: MEM [B = 0.70, 95% confidence interval (CI) 0.35-1.05]; EXEC (B = 0.88, 95% CI 0.41-1.36), and SPEED (B = 0.57, 95% CI 0.21-0.92).

CONCLUSIONS

Poorer cognitive performance on the domains MEM, EXEC and SPEED, but not WMEM, was associated with higher levels of depressive symptoms over 7 years of follow-up, but not with a different course of depressive symptoms over time.

Adverse Childhood and Recent Negative Life Events: Contrasting Associations With Cognitive Decline in Older Persons

OBJECTIVE

To examine whether persons who experienced adverse childhood events or recent negative life events have a worse cognitive performance and faster cognitive decline and the role of depression and apolipoprotein E-∊4 in this relationship.

METHODS

The community-based sample consisted of 10-year follow-up data of 1312 persons participating in the Longitudinal Aging Study Amsterdam (age range 65-85 years).

RESULTS

Persons who experienced adverse childhood events showed a faster 10-year decline in processing speed but only when depressive symptoms were experienced. Persons with more recent negative life events showed slower processing speed at baseline but no faster decline.

CONCLUSIONS

Childhood adversity may cause biological or psychological vulnerability, which is associated with both depressive symptoms and cognitive decline in later life. The accumulation of recent negative life events did not affect cognitive functioning over a longer time period.

What predicts persistent depression in older adults across Europe? Utility of clinical and neuropsychological predictors from the SHARE study

BACKGROUND

Depression in later life frequently persists and perpetuating factors are of immediate therapeutic relevance to clinicians. No studies of this scale have examined both clinical and neuropsychological predictors of persistent depression in a cross-national European context.

METHODS

4095 community dwelling older adults (≥ 50 yr) with clinically signficant depression (EURO-D ≥ 4) from eleven European countries in the Survey of Heath, Ageing, and Retirement in Europe (SHARE) were followed for a median of 28 months. Logistic regression analyses were conducted to determine predictors of persistent depression.

RESULTS

2187 (53.4%) remained depressed at follow up. Independent predictors included: female gender, baseline functional impairment, functional decline, physical symptoms, past history of depression, increased severity of depression, early age of onset (< 50 yr), life events, financial distress and country of residence. Neuropsychological variables were associated with persistent depression but not independently of other variables.

LIMITATIONS

The assessment of depression was by self-report and the data source did not contain a number of potentially relevant predictors.

CONCLUSION

Individuals at risk of persistent depression may be identified and targeted for intervention. Therapeutic interventions should adopt a multimodal approach to optimise current function, prevent further functional decline and treat symptoms of depression. Country of residence may be associated with further modifiable variables.

Depression and cognition: how do they interrelate in old age?

OBJECTIVES

To disentangle the reciprocal effects between depressive symptoms and cognitive functioning over time and to study the association between changes in their trajectories using 13 years of follow-up.

DESIGN AND PARTICIPANTS

Data were used from five waves of the population-based Longitudinal Aging Study Amsterdam. Subjects were included if data was present on depressive symptoms and cognitive performance on at least two occasions, which resulted in a study sample of N = 2,299.

MEASUREMENTS

Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression Scale. Cognitive functioning was assessed using the Mini-Mental State Examination (general cognitive functioning) and timed coding task (speed of information processing).

RESULTS

Cross-domain latent change analyses showed that depression at baseline predicted both decline of general cognitive functioning and information processing speed, independent of relevant covariates. Conversely, information processing speed at baseline, but not general cognitive functioning was related to the course of depressive symptoms. The course of cognitive functioning was not significantly associated with the course of depressive symptoms.

CONCLUSION

Depressive symptoms in older patients flag an increased likelihood of cognitive decline. This effect is considerable and may be due to several underlying mechanisms. The likelihood of the relationship reflecting either a causal effect of depression on cognitive decline, or a common cause, or both, should be estimated. Likewise, older persons with more limitations in information processing speed specifically are more vulnerable to increases in depression.

Biological basis of late life depression

Late life depression (LLD) is an important area of research given the growing elderly population. The purpose of this review is to examine the available evidence for the biological basis of LLD. Structural neuroimaging shows specific gray matter structural changes in LLD as well as ischemic lesion burden via white matter hyperintensities. Similarly, specific neuropsychological deficits have been found in LLD. An inflammatory response is another possible underlying contributor to the pathophysiology of LLD. We review the available literature examining these multiple facets of LLD and how each may affect clinical outcome in the depressed elderly.

Depression and cognitive impairment in older adults

Late life depression (LLD) is a heterogeneous illness with high rates of treatment resistance. Cognitive impairment is common in the context of LLD, and LLD may be a prodromal symptom and/or potentially a risk factor for dementia. This manuscript reviews the most recent research into the cognitive deficits associated with LLD and risk of conversion to dementia in the context of LLD. We discuss potential moderators and mediators of cognitive deficits in LLD, including demographic and clinical variables, in addition to brain structure and function. Potential interventions for cognitive symptoms of LLD are reviewed. We conclude with a discussion of the broader implications of what is now known about LLD, and how this might be applied toward improved prognosis and models for effective treatment.