Do severity and duration of depressive symptoms predict cognitive decline in older persons? Results of the Longitudinal Aging Study Amsterdam

Association between depressive duration and cognitive decline in middle-aged and older adults: Evidence from the Health and Retirement Study 2010-2018

BACKGROUND

Depression has been found to be associated with cognitive decline, but whether longer depressive durations lead to more severe cognitive declines has not been investigated. We aimed to estimate the association between depressive duration and cognitive decline in middle-aged and older Americans based on a large-scale representative population study.

METHODS

We included 27,886 participants from the Health and Retirement Study (HRS) in 2010-2018. Four datasets with 2-, 4-, 6-, and 8-year consecutive interviews were further derived which involving persistent depressed and persistent depression-free individuals. Multiple linear regressions were constructed to estimate the effects of each depressive duration on the decline in global cognition, memory and mental status. Meta-regressions were performed to test the linear trends and to explore the heterogeneity between sex, age and baseline cognitive function along with subgroup analyses.

RESULTS

Depressive durations of 2, 4, 6, and 8 years were associated with reductions in global cognitive scores of 0.62 points (95% CI: 0.51-0.73), 0.77 points (95% CI: 0.60-0.94), 0.83 points (95% CI: 0.55-1.10), and 1.09 points (95% CI: 0.63-1.55), respectively, indicating a linear trend (P = 0.016). More pronounced associations were observed in middle-aged adults and females. Similar patterns were found in the associations between depressive duration and two subdomains, i.e., memory and mental health.

LIMITATIONS

This study is essentially a cross-sectional study and therefore cannot provide causal associations.

CONCLUSIONS

Longer depressive durations were linearly related to more severe cognitive declines. Timely intervention for depression targeted middle-aged adults can more effectively alleviate cognition-related burdens.

Depressive Symptoms, Glial Fibrillary Acid Protein Concentrations, and Cognitive Decline in a Cohort Study

BACKGROUND

Little is known about how depressive symptoms and glial fibrillary acid protein (GFAP) concentrations taken together may influence cognitive functioning. Understanding this relationship may inform strategies for screening and early intervention to decrease the rate of cognitive decline.

METHODS

This study sample includes 1 169 participants from the Chicago Health and Aging Project (CHAP), consisting of 60% Black participants and 40% White participants, and 63% female participants and 37% male participants. CHAP is a population-based cohort study of older adults with a mean age of 77 years. Linear mixed-effects regression models tested the main effects of depressive symptoms and GFAP concentrations and their interactions on baseline cognitive function and cognitive decline over time. Models included adjustments for age, race, sex, education, chronic medical conditions, body mass index, smoking status, alcohol use, and their interactions with time.

RESULTS

The interaction of depressive symptomology and GFAP (β = -0.105 [standard error = 0.038], p = .006) on global cognitive function was statistically significant. Participants with depressive symptoms including and above the cutoff and high log of GFAP concentrations had more cognitive decline over time, followed by participants with depressive symptoms below the cutoff and high log of GFAP concentrations, depressive symptom scores including and above the cutoff and low log of GFAP concentrations, and depressive symptom scores below the cutoff and low log of GFAP concentrations.

CONCLUSIONS

Depressive symptoms have an additive effect on the association between the log of GFAP and baseline global cognitive function.

Depressive symptoms and cognitive impairment: A 10-year follow-up study from the Survey of Health, Ageing and Retirement in Europe

BACKGROUND

Depressive symptoms and cognitive impairment often coexisted in the elderly. This study investigates the effect of late-life depressive symptoms on risk of mild cognitive impairment (MCI).

METHODS

A total of 14,231 dementia- and MCI free participants aged 60+ from the Survey of Health, Ageing, and Retirement in Europe were followed-up for 10 years to detect incident MCI. MCI was defined as 1.5 standard deviation (SD) below the mean of the standardized global cognition score. Depressive symptoms were assessed by a 12-item Europe-depression scale (EURO-D). Severity of depressive symptoms was grouped as: no/minimal (score 0-3), moderate (score 4-5), and severe (score 6-12). Significant depressive symptoms (SDSs) were defined as EURO-D score ≥ 4.

RESULTS

During an average of 8.2 (SD = 2.4)-year follow-up, 1,352 (9.50%) incident MCI cases were identified. SDSs were related to higher MCI risk (hazard ratio [HR] = 1.26, 95% confidence intervals [CI]: 1.10-1.44) in total population, individuals aged 70+ (HR = 1.35, 95% CI: 1.14-1.61) and women (HR = 1.28, 95% CI: 1.08-1.51) in Cox proportional hazard model adjusting for confounders. In addition, there was a dose-response association between the severity of depressive symptoms and MCI incidence in total population, people aged ≥70 years and women (p-trend <0.001).

CONCLUSIONS

Significant depressive symptoms were associated with higher incidence of MCI in a dose-response fashion, especially among people aged 70+ years and women. Treating depressive symptoms targeting older population and women may be effective in preventing MCI.

Temporal Relationship Between Depressive Symptoms and Cognition in Mid and Late Life: A Longitudinal Cohort Study

OBJECTIVES

To examine the bidirectional temporal relationship between depressive symptoms and cognition in relation to risk, reaction, and prodrome.

DESIGN

Cross-lag analysis of longitudinal data collected online at baseline and 12-month follow-up.

SETTING AND PARTICIPANTS

A United Kingdom population cohort of 11,855 participants aged 50 years and over.

MEASURES

Patient Health Questionnaire-9 (depressive symptoms), cognitive measures: Paired Associate Learning, Verbal Reasoning, Spatial Working Memory, and Digit Span.

RESULTS

Depressive symptoms predicted a decline in paired associates learning [β = -.020, P = .013, (95% confidence interval [CI], ‒.036, -.004)] and verbal reasoning [β = -.014, P = .016, (95% CI ‒.025, -.003)] but not vice versa. Depressive symptoms predicted [β = -.043, P < .001, (95% CI ‒.060, -.026); β = -.029, P < .001, (95% CI ‒.043, -.015)] and were predicted by [β = -.030, P = < .001, (95% CI ‒.047, -.014); β = -.025, P = .003, (95% CI ‒.041, -.009)], a decline in spatial working memory and verbal digit span, respectively.

CONCLUSIONS AND IMPLICATIONS

Depressive symptoms may be either a risk factor or prodrome for cognitive decline. In addition, a decline in attention predicts depressive symptoms. Clinical implications and implications for further research are discussed.

Brain Aging in Midlife: The Beaver Dam Offspring Study

OBJECTIVES

Middle age has been identified as a critical time period for health later in life. Identifying factors associated with worse brain function in middle-aged adults may help identify ways to preserve brain function with aging. Our objective was to evaluate factors associated with a novel measure of brain aging in middle-aged and older adults.

DESIGN

Longitudinal cohort study.

SETTING

Beaver Dam Offspring Study (BOSS) baseline (2005-2008), 5-year (2010-2013), and 10-year examinations (2015-2017).

PARTICIPANTS

A total of 2285 adults, 22 to 84 years of age, with complete sensorineural and neurocognitive data at the 5-year examination.

MEASUREMENTS

Principal component analysis (PCA) was performed combining 5-year sensorineural (hearing, vision, olfaction) and cognitive (Trail Making Test A and B, Digit Symbol Substitution Test, Verbal Fluency Test, Auditory Verbal Learning Test) test data. Participants with a standardized PCA score less than -1 were classified as having brain aging. Incident brain aging was defined as a PCA score less than -1 at 10 years among participants who had a PCA score of -1 or higher at 5 years. Logistic regression and Poisson models were used to estimate associations between baseline factors and prevalent or incident brain aging, respectively.

RESULTS

Older age, being male, current smoking, larger waist circumference, not consuming alcohol, cardiovascular disease, and interleukin-6 were associated with greater odds of prevalent brain aging, whereas more education and exercise were associated with decreased odds. In addition to age and sex, less than a college education, higher levels of soluble intercellular adhesion molecule-1, diabetes, depressive symptoms, and history of head injury were associated with an increased 5-year risk of incident brain aging.

CONCLUSION

In the current study, vascular and inflammatory factors were associated with a new brain aging marker in middle-aged and older adults. Many of these factors are modifiable, highlighting the importance of addressing health and lifestyle factors in midlife to potentially preserve function for better brain health later in life. J Am Geriatr Soc 67:1610-1616, 2019.

Persistent depressive symptoms and cognitive decline in older adults

BACKGROUND

Little is known about the effect of persistent depressive symptoms on the trajectory of cognitive decline.AimsWe aimed to investigate the longitudinal association between the duration of depressive symptoms and subsequent cognitive decline over a 10-year follow-up period.

METHOD

The English Longitudinal Study of Ageing cohort is a prospective and nationally representative cohort of men and women living in England aged ≥50 years. We examined 7610 participants with two assessments of depressive symptoms at wave 1 (2002-2003) and wave 2 (2004-2005), cognitive data at wave 2 and at least one reassessment of cognitive function (wave 3 to wave 7, 2006-2007 to 2014-2015).

RESULTS

The mean age of the 7610 participants was 65.2 ± 10.1 years, and 57.0% were women. Of these, 1157 (15.2%) participants had episodic depressive symptoms and 525 participants (6.9%) had persistent depressive symptoms. Compared with participants without depressive symptoms at wave 1 and wave 2, the multivariable-adjusted rates of global cognitive decline associated with episodic depressive symptoms and persistent depressive symptoms were faster by -0.065 points/year (95% CI -0.129 to -0.000) and -0.141 points/year (95% CI -0.236 to -0.046), respectively (P for trend < 0.001). Similarly, memory, executive and orientation function also declined faster with increasing duration of depressive symptoms (all P for trend < 0.05).

CONCLUSIONS

Our results demonstrated that depressive symptoms were significantly associated with subsequent cognitive decline over a 10-year follow-up period. Cumulative exposure of long-term depressive symptoms in elderly individuals could predict accelerated subsequent cognitive decline in a dose-response pattern.Declaration of interestNone.

Gait Speed and Processing Speed as Clinical Markers for Geriatric Health Outcomes

OBJECTIVE

This study investigates the independent and combined potential of slowed gait speed and slowed processing speed as predictors of adverse health outcomes. The role of depressive symptoms in these associations is also investigated.

METHODS

In the prospective cohort study, using the Longitudinal Aging Study Amsterdam database, three study samples for each outcome variable were defined: persistent cognitive decline (PCD; N = 1,271, 13 years of follow-up), falls (N = 1,282, 6 years of follow-up), and mortality (N = 1,559, age 74.9 ± 5.8, 21 years of follow-up). At baseline, gait speed (6-m walk with a turn at 3 m), processing speed (coding task), depressive symptoms (Center for Epidemiologic Studies Depression Scale), and basic demographic data were assessed. Also, time to PCD, falls, and mortality were assessed. Cox (for PCD and mortality) and stratified Cox (for falls) regression models were used.

RESULTS

Slowed processing speed predicted PCD (HR: 7.8; 95% CI: 3.3-18.8), slowed gait speed predicted falls (HR: 1.3; 95% CI: 1.0-1.5), and both measures predicted mortality (gait speed HR: 2.1; 95% CI: 1.6-2.6; processing speed HR: 1.9; 95% CI: 1.6-2.4). Each association remained significant after adjusting for the other slowing symptom. Slowed processing speed only predicted falls in the presence of slowed gait (interaction). A slowing sum score that combines both slowing symptoms predicted all three outcomes. The associations were not influenced by depressive symptoms.

CONCLUSION

Slowing of thought is as relevant as slowing of movement to predict adverse health outcomes, because they seem to represent separate underlying pathologies.

A 13-year prospective cohort study on the effects of aging and frailty on the depression-pain relationship in older adults

OBJECTIVES

The primary aim of the study is to investigate the effect of age and aging on the association between pain and depression over 13 years. We hypothesized that (1) this association would become stronger with age and frailty and that (2) this association is mainly driven by somatic and psychological factors.

METHODS

Data were derived from the Longitudinal Aging Study Amsterdam, a prospective population-based cohort study with four follow-up measurements over 13 years, consisting of 1528 respondents (mean age 67.9 ± 8.1). Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale; pain was measured with an adapted version of the Nottingham Health Profile. Follow-up time and age were used as proxy variables for aging and gait speed as frailty marker. Cognition, mastery and neuroticism were measured using the mini mental state examination, the Pearlin Mastery Scale and the Dutch Personality Questionnaire respectively.

RESULTS

Linear mixed models showed that pain and depressive symptoms were associated over the 13-year follow-up: b = 0.095, p < 0.001. Neither aging nor frailty changed this association. Measured somatic and psychological characteristics explained 40% of the covariance between pain and depressive symptoms over time.

DISCUSSION

When dealing with people suffering from pain and depression, interventions should be similar for all aged people, encompassing both somatic and psychological factors, irrespective of age or frailty status.

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.

Does subjective sleep affect cognitive function in healthy elderly subjects? The Proof cohort

OBJECTIVE

Some epidemiological data are available on the association between sleep duration and sleep quality, sleep complaints, and the aging related cognitive impairment in the elderly. In this study we examined a large sample of healthy elderly subjects to assess the relationship between sleep quality, subjective cognitive complaints, and neuropsychological performance.

METHODS

A total of 272 elderly subjects (mean age 74.8 ± 1.1 years) were recruited from a population-based cross-sectional study on aging and cardiovascular morbidity. All subjects filled in self-assessment questionnaires evaluating cognitive function, anxiety, depression, sleep-related parameters, and the Pittsburgh Sleep Quality Index (PSQI). Ambulatory polygraphy and extensive neuropsychological tests were also performed. Based on the total PSQI score, subjects were classified as good sleepers (GS, PSQI<5, n=116) and poor sleepers (PS, PSQI≥5, n=156).

RESULTS

Poor sleep did not affect the subjective cognitive function score, subjective cognitive impairment being mainly related to anxiety, depression, and sleep medication intake. No significant differences were seen between GS and PS in any of the objective cognitive function tests except for the Trail Making Test A (TMA-A), processing speed being longer in the PS group (p<0.001). Neither the presence of sleep-related breathing disorders nor gender affected cognitive performance.

CONCLUSIONS

Our results suggest that in healthy elderly subjects, subjective sleep quality and duration did not significantly affect subjective and objective cognitive performances, except the attention level, for that the interference of sleep medication should be considered.

An evaluation of analytical approaches for understanding change in cognition in the context of aging and health

OBJECTIVES

In this article, we discuss the importance of studying the relationship between health and cognitive function, and some of the methods with which this relationship has been studied.

METHODS

We consider the challenges involved, in particular operationalization of the health construct and causal inference in the context of observational data. We contrast the approaches taken, and review the questions addressed: whether health and cognition are associated, whether changes in health are associated with changes in cognition, and the degree of interdependency among their respective trajectories.

RESULTS

A variety of approaches for understanding the association between cognition and health in aging individuals have been used. Much of the literature on cognitive change and health has relied on methods that are based at least in part on the reorganization of between-person differences (e.g., cross-lag analysis) rather than relying more fully on analysis of within-person change and joint analysis of individual differences in within-person change in cognition and health.

DISCUSSION

We make the case for focusing on the interdependency between within-person changes in health and cognition and suggest methods that would support this.

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

OBJECTIVES

To investigate whether specific domains of cognitive functioning predict the natural course of depressive symptoms in older people.

DESIGN AND PARTICIPANTS

Using the nationally representative, population-based cohort of the Longitudinal Aging Study Amsterdam, 281 participants with clinically relevant depressive symptoms (Center for Epidemiological Studies Depression Scale ≥16) aged 55 years and older were followed longitudinally during a period of 6 years.

MEASUREMENTS

Using a maximum of 14 successive Center for Epidemiological Studies Depression Scale observations, three clinical course types of depressive symptoms were defined. At baseline, general cognitive functioning was assessed using the Mini-Mental State Exam, memory performance (immediate recall and retention) by means of the auditory verbal learning test, and processing speed by means of a timed coding task.

RESULTS

Remission, fluctuating course, and chronic course were seen in 22%, 50%, and 28%, respectively. In univariate analyses, a slowed processing speed was associated with a chronic course of depressive symptoms, as compared with remission (mean: 21.5, SD: 6.6, versus mean: 24.6, SD: 6.8, t = 2.78, df = 139, p < 0.001). Using multivariate regression techniques, this association remained significant after correcting for potential confounders and a number of risk factors for vascular brain damage (odds ratio: 1.08, 95% confidence interval: 1.01-1.14). Neither global cognitive functioning nor memory performance was associated with any course type of depressive symptoms.

CONCLUSION

We found an independent association of a slowed processing speed with a poor natural course of depressive symptoms in older people. In clinical practice, when dealing with an older depressed person with comorbid cognitive decline, processing speed might be a more useful tool than the Mini-Mental State Exam in predicting the prognosis.

Depressive symptoms, chronic diseases, and physical disabilities as predictors of cognitive functioning trajectories in older Americans

OBJECTIVES

To determine the concurrent influence of depressive symptoms, medical conditions, and disabilities in activities of daily living (ADLs) on rates of decline in cognitive function of older Americans.

DESIGN

Prospective cohort.

SETTING

National population based.

PARTICIPANTS

A national sample of 6,476 adults born before 1924.

MEASUREMENTS

Differences in cognitive function trajectories were determined according to prevalence and incidence of depressive symptoms, chronic diseases, and ADL disabilities. Cognitive performance was tested five times between 1993 and 2002 using a multifaceted inventory examined as a global measure (range 0-35, standard deviation (SD) 6.0) and word recall (range 0-20, SD 3.8) analyzed separately.

RESULTS

Baseline prevalence of depressive symptoms, stroke, and ADL limitations were independently and strongly associated with lower baseline cognition scores but did not predict future cognitive decline. Each incident depressive symptom was independently associated with a 0.06-point lower (95% confidence interval (CI)=0.02-0.10) recall score, incident stroke with a 0.59-point lower total score (95% CI=0.20-0.98), each new basic ADL limitation with a 0.07-point lower recall score (95% CI=0.01-0.14) and a 0.16-point lower total score (95% CI=0.07-0.25), and each incident instrumental ADL limitation with a 0.20-point lower recall score (95% CI=0.10-0.30) and a 0.52-point lower total score (95% CI=0.37-0.67).

CONCLUSION

Prevalent and incident depressive symptoms, stroke, and ADL disabilities contribute independently to poorer cognitive functioning in older Americans but do not appear to influence rates of future cognitive decline. Prevention, early identification, and aggressive treatment of these conditions may ameliorate the burdens of cognitive impairment.

The NIH Cognitive and Emotional Health Project. Report of the Critical Evaluation Study Committee

BACKGROUND

The Cognitive and Emotional Health Project (CEHP) seeks to identify the demographic, social, and biological determinants of cognitive and emotional health in the older adult. As part of the CEHP, a critical evaluation study committee was formed to assess the state of epidemiological research on demographic, social, and biological determinants of cognitive and emotional health.

METHODS

Criteria for inclusion in the survey were large cohort studies, longitudinal in design, participants predominantly 65 years or older, with measurements of both cognition and emotion, and information on a wide variety of demographic, psychosocial, and biological factors. North American and European studies, which met these criteria, were selected for the review. Outcome measures included cognition, cognitive decline, and cognitive function. For emotion, symptoms included depression and anxiety, positive and negative affect, subjective well being, mastery, and resilience.

RESULTS

Ninety-six papers were identified that addressed cognitive and emotional outcomes. A large variety of risk factors were consistently identified with cognitive outcomes, particularly those previously associated with increased risk of cardiovascular disease. There was considerable overlap between risk factors for cognitive and emotional outcomes.

CONCLUSION

This review identifies a large number of lifestyle and health behaviors that alter the risk for maintenance of cognitive and emotional health. Large longitudinal cohort studies are a unique source to explore factors associated with cognitive and emotional health. Secondary analyses of these studies should be encouraged as should the development of standardized questionnaires to measure cognitive and emotional health. Future research in this field should study cognitive and emotional health simultaneously.

Usual sleep duration and cognitive function in older adults in Spain

The few studies that have examined the association between usual sleep duration and cognitive function have shown conflicting results. This cross-sectional study examined the association between sleep duration and cognitive function among 3212 people, representative of the non-institutionalized population aged 60 years and over in Spain. Sleep duration was self-reported, and cognitive function was measured with the Mini-Examen Cognoscitivo (MEC), a version of the Mini-Mental State Examination that has been validated in Spain. Linear regression, with adjustment for the main confounders, was used to obtain mean differences in the MEC between the categories of sleep duration (<or=5, 6, 7, 8, 9, 10, >or=11 h day(-1)). The MEC score decreased progressively (became worse) across sleep categories from 7 to >or=11 h (P for linear trend <0.001). People who slept for >or=11 h had a significantly lower MEC score than those who slept for 7 h (mean difference -1.48; 95% confidence interval -2.12 to -0.85). This difference in the MEC was similar to that observed for a 10-year increase in age. The results did not vary significantly by sex (P for interaction >0.05). No association was observed between short sleep duration (<7 h) and cognitive function. We conclude that long sleep duration is associated with poorer cognitive function in older adults from the general population.

APOE-epsilon4, depressive symptoms, and cognitive decline in Chinese older adults: Singapore Longitudinal Aging Studies

BACKGROUND

The precise relationship between depression and cognitive decline in older adults is unclear. We investigated the influence of apolipoprotein E (APOE)-epsilon4 genotype in modulating the effect of depressive symptoms on cognitive decline.

METHODS

Prospective cohort study of 1,487 cognitively high-functioning Chinese older adults. Depressive symptoms (Geriatric Depression Scale score >/=5) and Mini-Mental State Examination (MMSE) were assessed at baseline, and cognitive decline (at least 1-point drop in MMSE) at 1-2 years after baseline.

RESULTS

There was no significant difference in cognitive decline between depressed (32.9%) and nondepressed (31.5%) participants in the whole sample or among non-APOE-epsilon4 carriers. Among APOE-epsilon4 carriers, depressed participants showed more cognitive decline (40.0%) than their nondepressed counterparts (28.6%), odds ratio = 2.89, 95% confidence interval: 1.03-8.12; p = .04, after controlling for age, gender, education, vascular risk factors/events, smoking, alcohol drinking, physical functioning, subjective memory complaint, length of follow-up, and baseline MMSE scores (p for interaction = .03).

CONCLUSIONS

Our study suggests that the presence of the APOE-epsilon4 allele significantly enhanced the risk of cognitive decline associated with depressive symptoms. This finding should be independently replicated in future studies.

Symptoms of anxiety and depression in the course of cognitive decline

BACKGROUND/AIMS

Anxiety and depression are common inpatients with cognitive decline and Alzheimer's disease (AD), and recognition and treatment of these symptoms can improve their quality of life. The present study investigates anxiety and depression in different phases of cognitive decline.

METHODS

The sample consisted of five groups of elderly people in different phases of cognitive decline; four from a community-based sample (Longitudinal Aging Study Amsterdam), and one group of elderly people diagnosed with AD. ANOVAs were performed to investigate group differences in the severity and prevalence of anxiety and depression, and comorbid anxiety and depressive symptoms.

RESULTS

The prevalence rates of anxiety, comorbid anxiety and depressive symptoms and depressive symptoms follow a pattern of an increasing prevalence as cognitive performance declines and a decrease in the prevalence when cognitive functioning is severely impaired. AD patients report fewest anxiety symptoms.

CONCLUSION

We found that the prevalence of anxiety symptoms, depressive symptoms and comorbid anxiety and depressive symptoms seems to increase in the early phase of cognitive decline, and decreases as cognitive functioning further declines. Elderly diagnosed with AD report less anxiety as expected, probably due to lack of insight caused by AD.

Acetylcholinesterase inhibitors and depressive symptoms in patients with mild to moderate Alzheimer's disease

BACKGROUND AND AIMS

Acetylcholinesterase inhibitor (AChEis) therapy in Alzheimer Disease (AD) has been shown to provide cognitive benefits and to slow progression of the disease. AChEis have also been demonstrated to improve behavioral symptoms, although there seem to be subtle differences in the magnitude of response. The aim of our study was to evaluate the effect of 16 weeks treatment with AChEis on depressive symptoms in a selected sample of AD patients in routine clinical practice.

SUBJECTS AND METHODS

A study of 135 patients with Alzheimer's disease. All subjects were assessed at baseline (upon initiation of AChEis therapy) and re-evaluated after 16 weeks.

RESULTS

At baseline, "Depressed" and "Not depressed" patients were categorized according to DSM IV criteria for depression in Alzheimer Disease. After 16 weeks of treatment with AchEis, we observed an improvement of mood in the "Depressed" patients. In this group "Mood symptoms", measured with GDS, were independently associated with GDS "Mood symptoms" at baseline, but not with improvement on cognition (mean change of MMSE), age or sex.

CONCLUSIONS

In depressed AD subjects, AChEis treatment improves depressive symptoms evaluated by GDS. This improvement is independent of cognition enhancement.

Depressive symptoms, major depressive episode and cognition in the elderly: the three-city study

OBJECTIVES

The relationship between depression and dementia in the elderly has been extensively studied but the tools used to define depressed subjects are heterogeneous between studies. The objective of this study was to examine the relationship between depression and cognitive performances by using multiple measures of depressive state.

METHODS

A sample of 7,869 nondemented community-dwelling persons aged >or=65 years participated in the study. Depressive symptoms were evaluated by the Center for Epidemiological Study Depression Scale and the Mini-International Neuropsychiatric Interview was used to assess history of major depressive episodes (MDE). Cognitive function was evaluated by several tests including the Mini-Mental State Examination (MMSE), Trail Making Test, Isaacs Set Test and Benton Visual Retention Test.

RESULTS

When studied in separate models, depressive symptoms were significantly related to lower cognitive performances for all neuropsychological tests after adjusting for potential confounders (p<0.0001), whereas subjects with current MDE had significantly lower performances in MMSE and Isaacs Set Test. When studied concomitantly, only high levels of depressive symptoms were related to lower cognitive performance, whereas existence of MDE (past or current) was no longer associated with cognitive performances.

CONCLUSIONS

These data suggest that once current depressive symptoms are taken into account, major depression (past or current) is not associated with lower cognitive performances in a community-based sample of elderly people aged >or=65 years.

The association of self-reported sleep duration, difficulty sleeping, and snoring with cognitive function in older women

We examined the association of sleep duration, snoring, and difficulty sleeping with cognitive function in a cohort of community-dwelling women. Women (n = 1844), aged 70 to 81 years at initial cognitive interview in 2000, are members of the Nurses' Health Study cohort. Women completed six tests of cognitive function encompassing general cognition, verbal memory, category fluency, and attention. We repeated the assessment 2 years later. We used linear regression models to obtain multivariate-adjusted mean differences in initial test performance, and in cognitive decline over time, across categories of sleep duration (< or =5,6,7,8,9+ hours/night), frequency of snoring (never, occasionally, regularly), and sleep difficulties (rarely/never, occasionally, regularly). In analyses of initial test performance, women sleeping < or =5 hours/night scored worse than women sleeping 7 hours/night (mean difference on global score combining all cognitive tests = 0.15 standard units, 95% CI: -0.28, -0.02). Women who regularly had difficulty falling or staying asleep scored 0.11 units lower on the global score (95% CI: -0.22, 0.01) compared with those who rarely had difficulty sleeping. These differences were equivalent to the mean differences in score observed between participants who were 4 to 5 years apart in age. We found no associations with snoring or with any of the sleep variables and cognitive decline over 2 years. Associations between sleep patterns and initial cognitive function may be clinically relevant given that diminished cognition is a risk factor for dementia. However, the lack of an association with prospective cognitive decline warrants further investigation.

Longitudinal change in memory performance associated with HTR2A polymorphism

We present a fresh approach to evaluating association with candidate genes and cognitive change by testing association for parameters describing individual growth curves from twins. Moderate genetic influences on memory in aging adults has been shown in quantitative genetic studies. A recently reported, association of a HTR2A polymorphism with episodic memory in young unrelated adults led us to investigate the association between a nearby polymorphism and longitudinal memory performance in the Swedish Adoption/Twin Study of Aging (SATSA). Analysis of growth curve parameters suggests that both how well individuals perform on figural memory at age 65 years and nonlinear change in figural memory performance across age are associated with HTR2A. Individuals with two copies of the common G allele demonstrated higher figural memory performance longitudinally than those with the less frequent A allele, with performance trajectories differing by 2-6% per year. These findings imply a role for the 5-HT2A serotonin receptor on the formation of episodic memories in older adults.

Cognitive decline and dementia in diabetes--systematic overview of prospective observational studies

AIMS/HYPOTHESIS

We systematically reviewed and summarised prospective data relating diabetes status to changes in cognitive function over time.

METHODS

Published reports of longitudinal studies that described assessment of cognitive function in people with diabetes were sought. Studies were included if they assessed cognitive function in participants with diabetes at the beginning and at follow-up. Studies were excluded if they had (1) a follow-up period of less than 1 year, (2) a rate of loss to follow-up in excess of 30%, or (3) described selected subgroups. Change in cognitive function was recorded as either the mean change in score and/or the proportion of individuals developing various degrees of change in cognitive function. A pooled estimate was calculated for the latter.

RESULTS

Of 1,165 abstracts and titles initially identified, 25 articles met the inclusion and exclusion criteria. Individuals with diabetes had a 1.2- to 1.5-fold greater change over time in measures of cognitive function than those without diabetes. When assessed by the Mini-Mental State Exam and the Digit Symbol Span tests, a diagnosis of diabetes increased the odds of cognitive decline 1.2-fold (95% CI 1.05-1.4) and 1.7-fold (95% CI 1.3-2.3), respectively . The odds of future dementia increased 1.6-fold (95% CI 1.4-1.8).

CONCLUSIONS/INTERPRETATION

Compared to people without diabetes, people with diabetes have a greater rate of decline in cognitive function and a greater risk of cognitive decline. Cognitive dysfunction should therefore be added to the list of chronic complications of diabetes.