Depressive symptoms, vascular risk factors, and Alzheimer's disease

Depression as a Risk Factor for Dementia: A Meta-Analysis

Dementia is a syndrome characterized by the deterioration of cognitive function beyond what is expected. The increased risk of developing this syndrome resulting from established modifiable risk factors, such as depressive episodes, is currently a subject of interest. The aim of this study was to review the scientific evidence that addresses the relationship between depression and dementia. A bibliographic search of the PubMed and PsycInfo databases for articles published over the past 20 years was conducted with the following medical subject heading terms: depression or depressive, dementia, and incidence or cohort studies. After articles meeting the inclusion criteria were selected, relevant moderating variables were grouped as sample characteristics, methodological characteristics, extrinsic characteristics, and outcome variables. The 26 selected studies resulted in a sample comprising 1,760,262 individuals. Statistical analysis revealed a pooled relative risk for the development of dementia of 1.82 (95% CI=1.62-2.06). The primary variables evaluated were the diagnostic methods for depression and dementia and the presence of depression. Other variables, such as mean age, methodological quality of each study, follow-up time, and publication year, were also evaluated. Age was statistically but not clinically significant. No relevant publication bias or alterations in the results were found when accounting for the quality of the studies. It is recommended that new moderating variables be evaluated or that existing variables be reformulated in future studies.

Effects of Vascular Risk Factors on the Association of Blood-Based Biomarkers with Alzheimer's Disease

Background

Comorbidities may influence the levels of blood-based biomarkers for Alzheimer's disease (AD). We investigated whether differences in risk factors or comorbid conditions might explain the discordance between clinical diagnosis and biomarker classifications in a multi-ethnic cohort of elderly individuals.

Aims

To evaluate the relationship of medical conditions and other characteristics, including body mass index (BMI), vascular risk factors, and head injury, with cognitive impairment and blood-based biomarkers of AD, phosphorylated tau (P-tau 181, P-tau 217), in a multi-ethnic cohort.

Methods

Three-hundred individuals, aged 65 and older, were selected from a prospective community-based cohort for equal representation among three racial/ethnic groups: non-Hispanic White, Hispanic/Latino and African American/Black. Participants were classified into four groups based on absence (Asym) or presence (Sym) of cognitive impairment and low (NEG) or high (POS) P-tau 217 or P-tau 181 levels, determined previously in the same cohort: (Asym/NEG, Asym/POS, Sym/NEG, Sym/POS). We examined differences in individual characteristics across the four groups. We performed post-hoc analysis examining the differences across biomarker and cognitive status.

Results

P-tau 217 or P-tau 181 positive individuals had lower BMI than P-tau negative participants, regardless of symptom status. Symptomatic and asymptomatic participants did not differ in terms of BMI. BMI was not a mediator of the effect of P-tau 217 or P-tau 181 on dementia. Frequencies of other risk factors did not differ between the four groups of individuals.

Conclusions

Participants with higher levels of P-tau 217 or P-tau 181 consistent with AD had lower BMI regardless of whether the individual was symptomatic. These findings suggest that weight loss may change with AD biomarker levels before onset of cognitive decline. They do not support BMI as a confounding variable. Further longitudinal studies could explore the relationship of risk factors with clinical diagnoses and biomarkers.

Depression and bone loss as risk factors for cognitive decline: A systematic review and meta-analysis

BACKGROUND

Depression is linked to Alzheimer's disease (AD) but it is unclear whether depression is also associated with cognitive decline in the preclinical phase and mild cognitive impairment (MCI). Previous meta-analyses have only investigated AD as an outcome without accounting for individuals showing cognitive decline that does not meet the diagnostic criteria for AD. Other potentially modifiable risk factors such as bone loss have also been less explored and there remains uncertainty around their temporal relationship with cognitive decline.

AIMS

To conduct a systematic review and meta-analysis investigating depression and bone loss as risk factors for subsequent cognitive decline.

METHODS

A comprehensive search strategy was developed and applied using four databases; MEDLINE Complete, Embase, PsycINFO and CINAHL Complete. The pooled summary effects were estimated as odds ratios with 95% confidence intervals using a random-effects model. The study protocol was registered with PROSPERO (ID: CRD42020159369).

RESULTS

A total of 75 longitudinal cohort studies were identified for meta-analysis, of which 70 examined the impact of depression on cognitive decline and five examined the impact of bone loss. Prior exposure to depression was found to be associated with cognitive score reduction (OR 1.33 95% CI 1.17, 1.51), MCI incidence (OR 1.52 95% CI 1.28, 1.79) and AD incidence (OR 1.79 95% CI 1.46, 2.2). Bone loss was also associated with the incidence of AD (OR=1.81 95% CI 1.28, 2.55).

CONCLUSIONS

Overall, the results support the hypothesis that depression is associated with subsequent cognitive decline. Bone loss was also found to be associated with AD incidence; however, due to the small number of studies, the results should be viewed with caution.

Depression and Dementia in Elderly People

BACKGROUND: Dementia itself is not a disease, but a constellation of symptoms caused by diseases and disorders that affect the brain. Dementia and depression are mental health problems commonly encountered in neuropsychiatric practice in the elderly. AIM: The aims study was to evaluate the prevalence of depression in elderly people with dementia and to see the association between them. METHODS: This is a retrospective cohort study associating dementia with depression among the population from 50 until to more than 85 years old in Shkodra City in Albania. Practically, the figure of 187 patients with dementia was selected using the cluster sampling method. Patients were considered to have depression when one or more ICD codes for depression were recorded as primary or secondary diagnosis. Multilogistic regression odds ratio (OR) was used to identify factors predicting severity of depression. RESULTS: A total figure of 187 patients with dementia were enrolled into the study for a period of 4 years. Approximately, the minimum age was 50 and maximum 89 years old with average 75 ± 8.1 std. The prevalence of depression among those patients with dementia resulted 44.9% (84/187). Almost 61% of patients had moderate depression and 28% of patients had severe depression. According to studies, male with dementia was the most predominant sex compared to female with percentage 60.4% and 39.6%, respectively. On the other hand, depression was being found more predominant to female patients with dementia, not to forget that female was 2.9 (OR) time in risk to develop depression compared to male 95% CI (1.6–5.4) p = 0.0005. We did not find a strong association between the late-life depressions than in depression in middle-aged adults. CONCLUSION: Depression in older adults is a serious concern, especially in dementia population, which often is underdiagnosed being masked by cognitive impairments. According to the case in question, the findings highlight a high prevalence of depression within the dementia patients. After numerous medical researches, we found a strong association between depression and gender, lifestyle, type, or residence with the dementia patients. As stated, the better knowledges in the interactions between the depression and dementia from the part of medical staff will likely contribute to the timely prevention, identification, and treatment of depression in the elderly and will influence on their quality of life.

Fibrinogen Levels and the Risk of Cerebrovascular Events in Older Adults With Both Depressive Symptoms and Cognitive Impairment: A Prospective Study

Depression and cognitive impairment have been identified as risk factors for cerebrovascular events (CVE), and one of their potential etiological pathways is inflammatory status. This prospective study aims to investigate the association between inflammatory markers and the risk of CVE in a population of 2659 older adults, enrolled in the Progetto Veneto Anziani (Pro.V.A.), with depressive symptoms, cognitive impairment, or both conditions. For each individual, we assessed at baseline the presence of depressive symptoms (defined as a Geriatric Depression Scale ≥11), cognitive impairment (defined as a Mini-Mental State Examination <24), and serum levels of fibrinogen, white blood cells (WBC), and erythrocyte sedimentation rate (ESR). During a 4.4-year follow-up, 188 (7.1%) participants had CVE. Among the inflammatory markers, high fibrinogen values were associated with a 50% higher risk of CVE in the whole sample, and with a 4-fold higher risk in individuals with both depressive symptoms and cognitive impairment (hazard ratio = 4.04, 95% confidence interval: 1.45-11.23). Elevated WBC were associated with a 5% higher risk of CVE in the whole sample and in those with both conditions. No significant association was observed with the ESR. In conclusion, our study found that high fibrinogen levels may predict the risk of CVE in older people with concomitant depressive symptoms and cognitive impairment. Therefore, fibrinogen could be considered as an easily accessible aging biomarker, which might estimate the chronic inflammatory status and its potential detrimental effects on the most vulnerable older adults.

Hypertension and Drug Adherence in the Elderly

Hypertension is highly prevalent after the age of 65 years affecting more than 60% of individuals in developed countries. Today, there is sufficient evidence from clinical trials that treating elderly subjects with hypertension with antihypertensive medications has a positive benefit/risk ratio even in very elderly patients (>80 years). In recent years, partial or total non-adherence has been recognized as major issues in the long-term management of hypertension in all age categories. However, whether non-adherence is more frequent in hypertensive patients older than 65 years or not is still a matter of debate and the common belief is that adherence is lower in older than in younger patients. Are clinical data supporting this belief? In this brief review, we discuss the topic of drug adherence in elderly in the context of the medical treatment of hypertension. Studies show that drug adherence is actually better in patients aged 65 to 80 years when compared to younger hypertensive patients (<50 years). However, in very old patients (>80 years) the prevalence of non-adherence does increase. In this patients' group, there are specific risk factors for non-adherence such as cognitive ability, depression, and health believes, in addition to classical risk factors for non-adherence. One important aspect in the elderly is the prescription of potentially inappropriate medications that will interfere with the adherence to necessary treatments. In this context, an interesting new concept was developed few years ago, i.e., the process of deprescribing. Thus, today, in addition to conventional guidelines recommendations (use of single pill combinations, individualization of treatments), the evaluation of cognitive abilities, the regular assessment of potentially inappropriate medications, and the process of deprescribing appear to be three new additional steps to improve drug adherence in the elderly and thereby ameliorate the global management of hypertension.

Cross-sectional and prospective inter-relationships between depressive symptoms, vascular disease and cognition in older adults

BACKGROUND

It has been proposed that vascular disease is the mechanism linking depression and cognition, but prospective studies have not supported this hypothesis. This study aims to investigate the inter-relationships between depressive symptoms, cognition and cerebrovascular disease using a well-characterised prospective cohort.

METHOD

Data came from waves 1 (2005-2007) and 2 (2007-2009) of the Sydney Memory and Ageing Study (n = 462; mean age = 78.3 years).

RESULTS

At wave 1, there was an association between depressive symptoms and white matter hyperintensity (WMH) volume [b = 0.016, t(414) = 2.34, p = 0.020]. Both depressive symptoms [b = -0.058, t(413) = -2.64, p = 0.009] and WMH volume [b = -0.011, t(413) = -3.77, p < 0.001], but not stroke/transient ischaemic attack (TIA) [b = -0.328, t(413) = -1.90, p = 0.058], were independently associated with lower cognition. Prospectively, cerebrovascular disease was not found to predict increasing depressive symptoms [stroke/TIA: b = -0.349, t(374.7) = -0.76, p = 0.448; WMH volume: b = 0.007, t(376.3) = 0.875, p = 0.382]. Depressive symptoms predicted increasing WMH severity [b = 0.012, t(265.9) = -3.291, p = 0.001], but not incident stroke/TIA (odds ratio = 0.995; CI 0.949-1.043; p = 0.820). When examined in separate models, depressive symptoms [b = -0.027, t(373.5) = -2.16, p = 0.032] and a history of stroke/TIA [b = -0.460, t(361.2) = -4.45, p < 0.001], but not WMH volume [b = 0.001, t(362.3) = -0.520, p = 0.603], predicted declines in cognition. When investigated in a combined model, a history of stroke/TIA remained a predictor of cognitive decline [b = -0.443, t(360.6) = -4.28, p < 0.001], whilst depressive symptoms did not [b = -0.012, t(359.7) = -0.96, p = 0.336].

CONCLUSIONS

This study is contrasted with previous prospective studies which indicate that depressive symptoms predict cognitive decline independently of vascular disease. Future research should focus on further exploring the vascular mechanisms underpinning the relationship between depressive symptoms and cognition.

Risk Factors, Neuroanatomical Correlates, and Outcome of Neuropsychiatric Symptoms in Alzheimer's Disease

BACKGROUND

An integrative model of neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) is lacking.

OBJECTIVE

In this study, we investigated the risk factors, anatomy, biology, and outcomes of NPS in AD.

METHODS

181 subjects were included from the Alzheimer's Disease Neuroimaging Study (ADNI). NPS were assessed with the Neuropsychiatric Inventory Questionnaire at baseline and 6 months. NPI >3 was used as a threshold for NPS positivity. Three NPS courses were characterized: 1) minimal/absent (negative at 0 and 6 months, n = 77); 2) fluctuating (positive only at one time point, n = 53); 3) persistent (positive at both time points, n = 51). We examined the association between NPS course and family history of dementia, personal history of psychiatric disorders, cerebrospinal fluid biomarkers, atrophy patterns, as well as longitudinal cognitive and functional measures at 12 and 24 months (MMSE, CDR-SOB, FAQ).

RESULTS

AD subjects with absent, fluctuating, or persistent NPS had similar CSF amyloid-β and tau levels. AD subjects with minimal/absent NPS had less personal history of psychiatric disorders (35%) than those with fluctuating (57%; p = 0.015) or persistent NPS (47%, not significant). At 24 months, AD subjects with persistent NPS had worse cognitive (MMSE; p = 0.05) and functional (CDR-SOB; p = 0.016) outcomes. Dorsolateral prefrontal atrophy was seen in persistent NPS, but not in fluctuating NPS.

CONCLUSIONS

Our results suggest that individuals with personal history of psychiatric disorders might be more vulnerable to develop NPS throughout the course of AD. The worst cognitive and functional outcomes associated with NPS in AD underscores the importance of monitoring NPS early in the disease course.

Dementia risk estimates associated with measures of depression: a systematic review and meta-analysis

OBJECTIVES

To perform a systematic review of reported HRs of all cause dementia, Alzheimer's disease (AD) and vascular dementia (VaD) for late-life depression and depressive symptomatology on specific screening instruments at specific thresholds.

DESIGN

Meta-analysis with meta-regression.

SETTING AND PARTICIPANTS

PubMed, PsycInfo, and Cochrane databases were searched through 28 February 2014. Articles reporting HRs for incident all-cause dementia, AD and VaD based on published clinical criteria using validated measures of clinical depression or symptomatology from prospective studies of general population of adults were selected by consensus among multiple reviewers. Studies that did not use clinical dementia diagnoses or validated instruments for the assessment of depression were excluded. Data were extracted by two reviewers and reviewed by two other independent reviewers. The most specific analyses possible using continuous symptomatology ratings and categorical measures of clinical depression focusing on single instruments with defined reported cut-offs were conducted.

PRIMARY OUTCOME MEASURES

HRs for all-cause dementia, AD, and VaD were computed where possible for continuous depression scores, or for major depression assessed with single or comparable validated instruments.

RESULTS

Searches yielded 121,301 articles, of which 36 (0.03%) were eligible. Included studies provided a combined sample size of 66,532 individuals including 6593 cases of dementia, 2797 cases of AD and 585 cases of VaD. The increased risk associated with depression did not significantly differ by type of dementia and ranged from 83% to 104% for diagnostic thresholds consistent with major depression. Risk associated with continuous depression symptomatology measures were consistent with those for clinical thresholds.

CONCLUSIONS

Late-life depression is consistently and similarly associated with a twofold increased risk of dementia. The precise risk estimates produced in this study for specific instruments at specified thresholds will assist evidence-based medicine and inform policy on this important population health issue.

Feelings of Hopelessness in Midlife and Cognitive Health in Later Life: A Prospective Population-Based Cohort Study

BACKGROUND

Several studies have found depression and depressive feelings to be associated with subsequent dementia. As dementias typically have a long preclinical development phase, it has been difficult to determine whether depression and depressive feelings reflect a concurrent underlying dementia disease, rather than playing a causative role. Our aim was to investigate hopelessness, one dimension of depressive feelings, and evaluate the likelihood of a prodromal versus a causative role of hopelessness feelings in dementia development.

METHODS

We invited a random sample of 2000 survivors from a representative population in Eastern Finland, originally investigated in midlife between 1972 and 1987, for re-examination an average of 21 years later. The age of the 1449 persons who accepted the invitation was between 39 and 64 years (mean 50.4 years) in midlife and between 65 and 80 (mean 71.3) at follow-up. To measure feelings of hopelessness in midlife and at follow-up, the participants indicated their level of agreement to two statements about their own possible future. We used logistic regression to investigate the association between the combined scores from these two items and cognitive health at follow-up, while adjusting for several health and life-style variables from midlife and for apolipoprotein E4 (ApoE4) status, depression and hopelessness feelings at follow-up. We compared the associations with late-life cognitive health when feelings of hopelessness were either measured in midlife or at the follow-up. In addition we analyzed the changes in hopelessness scores from midlife to follow-up in participants who were either cognitively healthy or impaired at follow-up.

RESULTS

We found higher levels of hopelessness in midlife, but not at follow-up, to be associated with cognitive impairment at follow-up; the adjusted odds ratio for each step of the five-level hopelessness scale was 1.30 (95% confidence interval 1.11-1.51) for any cognitive impairment and 1.37 (1.05-1.78) for Alzheimer's disease. These associations remained significant also after the final adjustments for depressive feelings and for hopelessness at follow-up. The individual changes in hopelessness scores between midlife and follow-up were not systematically related to cognitive health at the follow-up.

CONCLUSION

Our results suggest that feelings of hopelessness already in midlife may have long-term implications for cognitive health and increase the risk of Alzheimer's disease in later life.

Alzheimer´s Disease associated with Psychiatric Comorbidities

Alzheimer's disease (AD) is the most common cause of dementia and has become a severe public health issue. It is estimated that globally, 35.6% of people have some form of dementia. This number is expected to double by 2030, and possibly even triple by 2050. The disease is associated with deficits in cognition/memory and a reduced ability in coping with everyday life. Moreover, patients can experience behavioral alterations such as mood swings, depression and hallucinations. Therefore, it is common to find the presence of neuropsychiatric comorbidities such as depression, schizophrenia and bipolar disorder during the course or development of AD. These disorders can become severe enough to interfere with the patients daily functioning, and can worsen the course of the disease. However, little is known about the causal relationship between psychiatric comorbidities and AD, or the reasons for the predisposition of some individuals to such disorders. Therefore, the purpose of this review is to clarify the causal relationship between depression, schizophrenia and bipolar disorder with AD.

Risk factors for age at onset of dementia due to Alzheimer's disease in a sample of patients with low mean schooling from São Paulo, Brazil

OBJECTIVE

In view of the mild effects of pharmacological treatment for dementia due to Alzheimer's disease (AD), the search for modifiable risk factors is an important challenge. Although risk factors for AD are widely recognized, elements that influence the time of onset of the dementia syndrome have not been comprehensively reported. We aimed to investigate which risk factors might be associated with the age at onset of AD in a sample of patients with low mean schooling from São Paulo, Brazil.

METHODS

We included 210 consecutive patients with late-onset AD to investigate whether education, gender, nationality, urban living and sanitation, occupation, cognitive and physical inactivity, head trauma, depression, systemic infections, surgical interventions, cerebrovascular risk factors, family history of neurodegenerative diseases or cardiovascular diseases and apolipoprotein E gene (APOE) haplotypes might be related to the age at AD onset.

RESULTS

Each copy of APOE-ε4 led to onset of AD almost 2 years earlier, while depression, smoking, higher body mass index and family history of cardiovascular diseases were also highly significant. Protective factors included non-Brazilian nationality, use of a pacemaker and waist circumference. Cerebrovascular risk factors had a mild combined effect for earlier onset of AD.

CONCLUSION

APOE haplotypes, depression, nationality and cerebrovascular risk factors were the most important elements to influence the age at AD onset in this sample, whereas gender, education, occupation and physical activities had no isolated effects over the age at onset of this dementia syndrome.

Depressive symptoms precede memory decline, but not vice versa, in non-demented older adults

OBJECTIVES

To determine whether depressive symptoms typically precede or follow memory declines.

DESIGN

An autoregressive latent trajectory model was used to examine the direction of the relationship between depressive symptoms and memory decline observed over 12 years.

SETTING

Washington/Hamilton Heights Inwood Columbia Aging Project, a community-based longitudinal study of aging and dementia in northern Manhattan.

PARTICIPANTS

Older adults initially without dementia(n = 2,425).

MEASUREMENTS

Memory composite scores were computed from three subscores of the Selective Reminding Test. Depressive symptoms were assessed using a 10-item version of the Center for Epidemiologic Studies Depression Scale. Analyses controlled for age, sex, recruitment wave,education, black race, and Hispanic ethnicity measured at baseline and chronic disease burden measured at each study visit.

RESULTS

Initial depressive symptoms predicted worse memory scores at the second study visit (B weight = − 0.03; P = .003) and accelerated memory decline over the entire study period (B weight = − 0.02; P = .03). Memory scores did not predict subsequent depressive symptoms.

CONCLUSION

These findings suggest that depressive symptoms precede memory decline, but not vice versa, in late life. This pattern of results is consistent with hypotheses that depression is a prodrome of dementia or a causal contributor to memory decline. Clinicians should be aware that depressive symptoms may represent an early indicator not only of dementia, as reported previously, but also of memory decline more generally.

Depressive symptoms predict cognitive decline and dementia in older people independently of cerebral white matter changes: the LADIS study

OBJECTIVE

Depressive symptoms (DS) have been associated with increased risk of cognitive decline. Our aim was to evaluate the longitudinal influence of DS on cognition in independent older people, accounting for the severity of white matter changes (WMC).

METHODS

The LADIS (Leukoaraiosis And DISability in the elderly) prospective study evaluated the impact of WMC on the transition of independent older subjects into disability. Subjects were evaluated annually over a 3 year period with a comprehensive clinical and neuropsychological evaluation. Previous episodes of depression and current DS were assessed during each interview. Severity of DS was assessed using the self-rated 15 item Geriatric Depression Scale. A neuropsychological battery and clinical criteria for cognitive impairments were applied in all clinical visits, and cognitive compound measures were made based on neuropsychological results. MRI was performed at baseline and at year 3.

RESULTS

639 subjects were included (74.1 ± 5 years old, 55% women, 9.6 ± 3.8 years of schooling). Dementia was diagnosed in 90 patients and cognitive impairment not dementia in 147 patients at the last clinical evaluation. DS were an independent predictor of cognitive impairment (dementia and not dementia) during follow-up, independent of the effect of the severity of WMC, medial temporal lobe atrophy, age, education or global cognitive function at baseline.

CONCLUSIONS

DS are associated with an increase risk of cognitive decline, independent of the effect of WMC, probably due to an additive or synergistic effect. In this context, DS probably represent a subtle ongoing organic dysfunction.

Late-life depression, mild cognitive impairment, and dementia

OBJECTIVE

To evaluate the association of late-life depression with mild cognitive impairment (MCI) and dementia in a multiethnic community cohort.

DESIGN AND SETTING

A cohort study was conducted in Northern Manhattan, New York, New York.

PARTICIPANTS

A total of 2160 community-dwelling Medicare recipients aged 65 years or older were included in the study.

METHODS

Depression was assessed using the 10-item version of the Center for Epidemiological Studies Depression scale (CES-D) and defined by a CES-D score of 4 or more. We used logistic regression for cross-sectional association analyses and proportional hazards regression for longitudinal analyses.

MAIN OUTCOME MEASURES

Mild cognitive impairment dementia, and progression from MCI to dementia were the main outcome measures. We also used subcategories of MCI (amnestic and nonamnestic), and dementia (probable Alzheimer disease and vascular dementia, including possible Alzheimer disease with stroke).

RESULTS

Baseline depression was associated with prevalent MCI (odds ratio, 1.4; 95% CI, 1.1-1.9) and dementia (2.2; 1.6-3.1). Baseline depression was associated with an increased risk of incident dementia (hazard ratio [HR], 1.7; 95% CI, 1.2-2.3) but not with incident MCI (0.9; 0.7-1.2). Persons with MCI and coexisting depression at baseline had a higher risk of progression to dementia (HR, 2.0; 95% CI, 1.2-3.4), especially vascular dementia (4.3; 1.1-17.0), but not Alzheimer disease (1.9; 1.0-3.6).

CONCLUSION

The association of depression with prevalent MCI and with progression from MCI to dementia, but not with incident MCI, suggests that depression accompanies cognitive impairment but does not precede it.

Affective disorders and risk of developing dementia: systematic review

BACKGROUND

Affective disorders are associated with cognitive disturbances but their role as risk factors for dementia is still not fully investigated.

AIMS

To evaluate the risk of developing dementia in individuals with a history of affective disorder.

METHOD

We conducted a systematic review of case-control and cohort studies addressing the risk of developing dementia in people with affective disorders. To the best of our knowledge, this is the first systematic review that has included studies evaluating this risk specifically in people with bipolar disorder.

RESULTS

Fifty-one studies were included. Most of the studies found an increased risk for developing dementia in individuals with depression. Greater frequency and severity of depressive episodes seem to increase this risk. The evidence is contradictory regarding whether there is a difference in risk in people with early- or late-onset depression. The few available risk estimates for dementia in people with bipolar disorder suggest an even higher risk than for those with depression.

CONCLUSIONS

Affective disorders appear to be associated with an increased risk of developing dementia, and one that is dependent on clinical and demographic variables. Depression may be both a prodrome and a risk factor for dementia. Future research should aim to elucidate the mechanisms that mediate these links.

Depression in Taiwanese patients with Alzheimer's disease determined by the National Institutes of Mental Health Provisional Criteria

BACKGROUND

Depression is a common behavioral and psychological symptom of Alzheimer's disease (AD). The aims of the present study were to determine the rate of depression in Taiwanese patients with AD using the National Institutes of Mental Health Provisional Criteria for Depression in AD (NIMH-dAD criteria) and to investigate the association of depression with other behavioral and psychological symptoms.

METHODS

A consecutive series of 302 AD patients registered in a dementia clinic were investigated in this study. All patients met the criteria of the National Institute of Neurological Disorders and Stroke-Alzheimer's Disease and Related Disorders Association for probable AD. The rates of depression were determined according to the criteria of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders for major depression (DSM-IV), the International Classification of Diseases-9-Clinical Modification (ICD-9-CM) for neurotic depression, the depression subscale of the Neuropsychiatric Inventory (NPI), and the NIMH-dAD criteria. Depression severity was assessed using the 17-item Hamilton Depression Rating Scale. The rates of depression determined by the NIMH-dAD criteria were compared with the rates derived from each of the other instruments. Other behavioral and psychological symptoms were assessed using NPI. A behavioral neurologist or a geriatric psychiatrist interviewed all the patients.

RESULTS

Using the NIMH-dAD criteria, it was found that 90 (29.8%) of the AD patients had depression, and all depressive symptoms in NIMH-dAD were significantly higher among depressed patients. Among other depression instruments, the frequency of depression was lowest using the DSM-IV major depression criteria (9.3%) and highest with the NPI depression subscale (54%). Behavioral and psychological symptoms determined with NPI were significantly higher among depressed patients in all domains except euphoria.

CONCLUSIONS

This is the first study of depression in Taiwanese patients with AD using the NIMH-dAD criteria. Our findings suggest that comorbid depression is high in Taiwanese patients with AD. It is clinically important to note the high frequency of most behavioral and psychological symptoms among depressed AD patients.

Dietary omega 3 polyunsaturated fatty acids and Alzheimer's disease: interaction with apolipoprotein E genotype

Epidemiological studies suggest a protective role of omega-3 poly-unsaturated fatty acids (n-3 PUFA) against Alzheimer's disease (AD). However, most intervention studies of supplementation with n-3 PUFA have yielded disappointing results. One reason for such discordant results may result from inadequate targeting of individuals who might benefit from the supplementation, in particular because of their genetic susceptibility to AD. The ε4 allele of the apolipoprotein E gene (ApoE) is a genetic risk factor for late-onset AD. ApoE plays a key role in the transport of cholesterol and other lipids involved in brain composition and functioning. The action of n-3 PUFA on the aging brain might therefore differ according to ApoE polymorphism. The aim of this review is to examine the interaction between dietary fatty acids and ApoE genotype on the risk for AD. Carriers of the ε4 allele tend to be the most responsive to changes in dietary fat and cholesterol. Conversely, several epidemiological studies suggest a protective effect of long-chain n-3 PUFA on cognitive decline only in those who do not carry ε4 but with inconsistent results. An intervention study showed that only non-carriers had increased concentrations of long-chain n-3 PUFA in response to supplementation. The mechanisms underlying this gene-by-diet interaction on AD risk may involve impaired fatty acids and cholesterol transport, altered metabolism of n-3 PUFA, glucose or ketones, or modification of other risk factors of AD in ε4 carriers. Further research is needed to explain the differential effect of n-3 PUFA on AD according to ApoE genotype.

Temporal relationship between depression and dementia: findings from a large community-based 15-year follow-up study

CONTEXT

Late-life depression is associated with increased risk of dementia, but the temporal relationship between depression and development of dementia remains unclear.

OBJECTIVES

To examine the association between risk of dementia and baseline depressive symptoms; history of depression, particularly early-life (<50 years) vs late-life depression (≥50 years); and individual domains of the Center for Epidemiologic Studies Depression Scale.

DESIGN

A large cohort with initially nondemented participants was followed up biennially for up to 15 years. Baseline depressive symptoms were assessed using the 11-item version of the Center for Epidemiologic Studies Depression Scale; presence of significant depressive symptoms was defined as a score of 11 or greater. Self-reported history of depression was collected at the baseline interview. Cox proportional hazards regression was used to assess the association between depression and dementia risk.

SETTING

Population-based cohort drawn from members of the Group Health Cooperative in Seattle, Washington.

PARTICIPANTS

A cohort of 3410 participants without dementia aged at least 65 years.

RESULTS

During a mean of 7.1 years of follow-up, 658 participants (19.3%) developed dementia. At baseline, 9.4% of participants had presence of significant depressive symptoms, and 21.2% reported a history of depression. The adjusted hazard ratio for dementia associated with baseline depressive symptoms was 1.71 (95% confidence interval, 1.37-2.13), after adjusting for age at entry, sex, educational level, and wave of enrollment. Compared with participants without depression history, those with late-life depression were at increased dementia risk (adjusted hazard ratio, 1.46; 95% confidence interval, 1.16-1.84), but early-life depression had no association with dementia risk (1.10 [0.83-1.47]). Depressed mood (adjusted hazard ratio, 1.48; 95% confidence interval, 1.25-1.76) and perceived performance difficulty (1.39 [1.15-1.67]) were independently associated with dementia.

CONCLUSION

This study confirmed that late-life depression is associated with increased risk of dementia and supplied evidence that late-life depression may be an early manifestation of dementia rather than increasing risk for dementia.

Depressive symptoms and incidence of mild cognitive impairment and probable dementia in elderly women: the Women's Health Initiative Memory Study

OBJECTIVES

To examine whether significant depressive symptoms in postmenopausal women increases the risk of subsequent mild cognitive impairment (MCI) and dementia.

DESIGN

Prospective cohort study.

SETTING

Thirty nine of the 40 Women's Health Initiative (WHI) clinical centers that participated in a randomized clinical trial of hormone therapy.

PARTICIPANTS

Six thousand three hundred seventy-six postmenopausal women without cognitive impairment aged 65 to 79 at baseline.

MEASUREMENTS

Depressive disorders were assessed using an eight-item Burnam algorithm and followed annually for a mean period of 5.4 years. A central adjudication committee classified the presence of MCI and probable dementia based on an extensive neuropsychiatric examination.

RESULTS

Eight percent of postmenopausal women in this sample reported depressive symptoms above a 0.06 cut point on the Burnam algorithm. Depressive disorder at baseline was associated with greater risk of incident MCI (hazard ratio (HR)=1.98, 95% confidence interval (CI)=1.33-2.94), probable dementia (HR=2.03, 95% CI=1.15-3.60), and MCI or probable dementia (HR=1.92, 95% CI=1.35-2.73) after controlling for sociodemographic characteristics, lifestyle and vascular risk factors, cardiovascular and cerebrovascular disease, antidepressant use, and current and past hormone therapy status. Assignment to hormone therapy and baseline cognitive function did not affect these relationships. Women without depression who endorsed a remote history of depression had a higher risk of developing dementia.

CONCLUSION

Clinically significant depressive symptoms in women aged 65 and older are independently associated with greater incidence of MCI and probable dementia.

Plasma amyloid beta-42 independently predicts both late-onset depression and Alzheimer disease

OBJECTIVES

Depression in the elderly might represent a prodromal phase of Alzheimer disease (AD). High levels of plasma amyloid beta-42 (Aβ42) were found in prestages of AD and also in depressed patients in cross-sectional studies. This study examined the association of emerging late-onset depression (LOD) and AD with plasma Aβ42 in a sample of never depressed and not demented persons at baseline.

DESIGN

Prospective 5-year longitudinal study.

PARTICIPANTS

A community dwelling of older adults (N = 331) from the Vienna Transdanube Aging study.

MEASUREMENTS

Laboratory measurements, cognitive functioning, and depressive symptoms were assessed at baseline, 2.5, and 5 years follow-ups.

RESULTS

After exclusion of converters to AD, regression analysis revealed that higher plasma Aβ42 at baseline was a positive predictor for conversion to first episode of LOD. Independent of whether persons with mild cognitive impairment (MCI) at 2.5 years were included or excluded into regressions, higher plasma Aβ42 at baseline was a significant predictor for the development of probable or possible AD at 5 years. Higher conversion to AD was also associated with male gender but not with either higher scores on the Geriatric Depression Scale (GDS), with stroke or cerebral infarction nor apolipoprotein E ε4 allele. No association was found for an interaction between plasma Aβ42 levels and GDS.

CONCLUSIONS

Higher plasma Aβ42 at baseline predicted the development of first episode of LOD and conversion to probable or possible AD. Emerging depression as measured by scores on GDS at the 2.5-year follow-up, either alone or as an interaction factor with plasma Aβ42, failed to predict the conversion to AD at 5 years.

Persistent depressive symptoms and cognitive function in late midlife: the Whitehall II study

OBJECTIVE

Depression has been widely linked to poor cognition and dementia in the elderly. However, comorbidity at older ages does not allow an assessment of the role of mental health as a risk factor for cognitive outcomes. We examined the association between depressive symptoms, measured 6 times over an 18-year period, and cognitive deficits in late midlife.

METHOD

Of the 10,308 participants in the Whitehall II study, 4,271 men and women (aged 35-55 years at baseline) were followed up for 18 years, during which depressive symptoms were assessed 6 times using the General Health Questionnaire depression subscale. The follow-up was from 1985-1988 to 2002-2004. Cognition was assessed at the most recent wave (2002-2004, mean age 61 years, range 50-74 years) using 6 tests: memory, reasoning, vocabulary, 2 tests of verbal fluency, and the MMSE (Mini Mental State Examination). Cognitive deficit was defined as MMSE score <28 and performance in the worst sex-specific quintile for the other tests.

RESULTS

History of depressive symptoms, once or more in the 6 times assessed, had a weak association with some of the cognitive tests. However, in analysis adjusted for sociodemographic variables, diabetes, coronary heart disease, hypertension, stroke, and antidepressant use, persistent depressive symptoms (4-6 times) were associated with cognitive deficits on all tests: memory (OR=1.91; 95% CI, 1.36-2.67), reasoning (OR=1.60; 95% CI, 1.15-2.20), vocabulary (OR=1.75; 95% CI, 1.27-2.41), phonemic fluency (OR=1.40; 95% CI, 1.00-1.94), semantic fluency (OR=1.68; 95% CI, 1.20-2.35), and the MMSE (OR=1.76; 95% CI, 1.25-2.50).

CONCLUSIONS

Our data show that depressive episodes tend to persist in some individuals, and these individuals are at a greater risk of cognitive deficits in late midlife.

Diagnostic correlates of Alzheimer dementia in a U.S. Nationwide inpatient sample

INTRODUCTION

Alzheimer dementia (ALZ-D) is among the most frequent diseases in the elderly. Several somatic and psychiatric disorders have been suggested to be related to this diagnosis. The aim of this analysis of a large and representative U.S. nationwide inpatient sample (NIS) was to identify diagnostic correlates of ALZ-D in subjects aged 60 years and older.

METHODS

Of the total sample of 800,457 inpatient subjects ( approximately 2% of all inpatients in 2004), 315,244 individuals were 60 years or older. Of these, 9,572 (3.03%) received a diagnosis of ALZ-D, whereas 33,367 (10.59%) were diagnosed with osteoarthritis (OA) and served as a comparison group. Comparisons of potential somatic and psychiatric diagnostic correlates were conducted.

RESULTS

As determined by both univariate comparison and multivariate logistic regression analysis, after controlling for age and gender, subjects with ALZ-D (versus OA) had an overall higher rate of diagnoses of diseases of the vascular system (stroke: odds ratio 1.69; 95% confidence interval: 1.25-2.30) and psychotic and affective disorders (bipolar: 2.78 [1.26-6.12]; schizoaffective: 3.06 [2.10-4.47]). Increasing age and male gender were positively associated with the diagnosis of ALZ-D.

DISCUSSION

Many somatic diagnoses related to ALZ-D were confirmed by these analyses of the NIS. However, psychotic and affective disorders were identified to be equally significant correlates of ALZ-D, even in the presence of all other disorders. Prospective and longitudinal data are needed to investigate potential causal and temporal relationships between ALZ-D with somatic and psychiatric disorders.

Depression, hypertension, and comorbidity: disentangling their specific effect on disability and cognitive impairment in older subjects

We aimed to demonstrate that depression and hypertension are associated independently of each other with disability and cognitive impairment in older subjects and that such an association is not attributable to number and severity of comorbidities. An observational study was performed on elderly patients admitted to the Hospital Network of the Italian National Research Center on Aging (INRCA) from January 2005 to December 2006. Depression was defined according to 15-item geriatric depression scale (GDS) score; physical disability according to activities of daily living (ADL) and instrumental activities of daily living (IADL) scores; cognitive impairment on the mini-mental state examination (MMSE) test; the number and severity of comorbidities by means of physician-administered cumulative illness rating scale (CIRS). Among 6180 older subjects (age=79.3 ± 5.8 years; 47% men), 48.3% were normotensive, 21.8% normotensive depressed, 21.7% hypertensive, and 8.2% hypertensive and depressed. Both depression and hypertension remained significantly associated with functional disability and cognitive impairment. When controlling for age, gender, the number and severity of comorbidities, hypertension was associated with a significantly higher likelihood of having functional disability or cognitive impairment only in the presence of depression (odds ratio=OR=2.02, 95% confidence interval=95%CI=1.60-2.54, p<0.001 for functional disability; OR=2.21, 95%CI=1.79-2.74, p<0.001 for cognitive impairment) as compared to normotensive controls without depression. We conclude that depression per se' or co-occurrence of hypertension and depression is associated with higher functional disability and cognitive impairment in older subjects. This effect is not attributable to the number or to the severity of comorbidities.

Associations between stroke risk and cognition in normal aging and Alzheimer's disease with and without depression

BACKGROUND

Stroke risk factors have been increasingly implicated in the development of age-related cognitive decline, the spectrum of vascular cognitive impairment, and, more recently, Alzheimer's disease (AD). In addition, depression and the apolipoprotein (APOE) epsilon4 allele have been reported to influence the association between stroke risk and cognition. However, few studies have described the relations among stroke risk, cognition, and APOE genotype in AD, and the findings have been equivocal.

METHODS

Thirty cognitively normal older adults, 30 AD patients with depression, and 30 AD patients without depression were administered a comprehensive neuropsychological battery measuring several domains including memory, attention, language, visuospatial skills, executive functions, and speed of information processing. The Framingham Stroke Risk Profile (FSRP), a validated scale that was developed to predict 10-year probability of stroke, was used to quantify stroke risk burden.

RESULTS

AD patients with depression demonstrated greater stroke risk burden relative to the cognitively normal group and, across all participants, increased stroke risk was associated with poorer performance on memory and processing speed measures. Moreover, stroke risk accurately predicted AD diagnosis. Notably, there were no significant differences in stroke risk or cognitive performance between the AD participants with depression and those without depression.

CONCLUSION

Given that many markers of stroke risk are modifiable or treatable, our findings have implications for assessment, prevention, and treatment of cognitive decline.

Perceptions of self-stigma and its correlates among older adults with depression: a preliminary study

BACKGROUND

Depression is common in old age and is often associated with stigma. However, to date, little is known about self-stigma (internalization of stigmatic beliefs) in depressed older people despite its importance and consequences. The aim of this study was to examine self-stigma and its correlates in depressed older people.

METHODS

Phone interviews were conducted with 54 persons diagnosed with major depression (78% female, average age = 74) from a psychogeriatric clinic in the central area of Israel. Self-stigma was assessed using an adapted version of the Internalized Stigma of Mental Health (ISMI) scale. Symptoms of depression were assessed using the short form of the Geriatric Depression Scale (GDS). Self-esteem was measured using Rosenberg's Self Esteem Scale. Information regarding sociodemographic and psychiatric health characteristics was also collected.

RESULTS

Self-stigma was relatively moderate with 10% to 20% of the participants reporting self-stigma. Those who reported higher levels of self-stigma were younger than those who did not report it. Income and education were lower in persons who reported high levels of stigmatization. Persons who reported stigmatization scored higher on the GDS and reported lower self-esteem than those without stigmatization.

CONCLUSIONS

This study represents an effort to examine the correlates of self-stigma in depressed older people. Since self-stigma exists among older adults, further studies are required to extend this body of knowledge.

Structural neuroimaging in Altheimer's disease: do white matter hyperintensities matter?

The targeted brain dysfunction that accompanies aging can have a devastating effect on cognitive and intellectual abilities. A significant proportion of older adults experience precipitous cognitive decline that negatively impacts functional activities. Such individuals meet clinical diagnostic criteria for dementia, which is commonly attributed to Alzheimer's disease (AD). Structural neuroimaging, including magnetic resonance imaging (MRI), has contributed significantly to our understanding of the morphological and pathology-related changes that may underlie normal and disease-associated cognitive change in aging. White matter hyperintensities (WMH), which are distributed patches of increased hyperintense signal on T2-weighted MRI, are among the most common structural neuroimaging findings in older adults. In recent years, WMH have emerged as robust radiological correlates of cognitive decline. Studies suggest that WMH distributed in anterior brain regions are related to decline in executive abilities that is typical of normal aging, whereas WMH distributed in more posterior brain regions are common in AD. Although epidemiological, observational, and pathological studies suggest that WMH may be ischemic in origin and caused by consistent or variable hypoperfusion, there is emerging evidence that they may also reflect vascular deposition of (β-amyloid, particularly when they are distributed in posterior areas and are present in patients with AD. Findings from the literature highlight the potential contribution of small-vessel cerebrovascular disease to the pathogenesis of AD, and suggest a mechanistic interaction, but future longitudinal studies using multiple imaging modalities are required to fully understand the complex role of WMH in AD.

Structural neuroimaging in Altheimer's disease: do white matter hyperintensities matter?

The targeted brain dysfunction that accompanies aging can have a devastating effect on cognitive and intellectual abilities. A significant proportion of older adults experience precipitous cognitive decline that negatively impacts functional activities. Such individuals meet clinical diagnostic criteria for dementia, which is commonly attributed to Alzheimer's disease (AD). Structural neuroimaging, including magnetic resonance imaging (MRI), has contributed significantly to our understanding of the morphological and pathology-related changes that may underlie normal and disease-associated cognitive change in aging. White matter hyperintensities (WMH), which are distributed patches of increased hyperintense signal on T2-weighted MRI, are among the most common structural neuroimaging findings in older adults. In recent years, WMH have emerged as robust radiological correlates of cognitive decline. Studies suggest that WMH distributed in anterior brain regions are related to decline in executive abilities that is typical of normal aging, whereas WMH distributed in more posterior brain regions are common in AD. Although epidemiological, observational, and pathological studies suggest that WMH may be ischemic in origin and caused by consistent or variable hypoperfusion, there is emerging evidence that they may also reflect vascular deposition of beta-amyloid, particularly when they are distributed in posterior areas and are present in patients with AD. Findings from the literature highlight the potential contribution of small-vessel cerebrovascular disease to the pathogenesis of AD, and suggest a mechanistic interaction, but future longitudinal studies using multiple imaging modalities are required to fully understand the complex role of WMH in AD.