Sex-Specific Associations Between Depressive Symptoms and Risk for Subsequent Dementia

Association of depressive symptoms and dementia among middle-aged and elderly community-dwelling adults: Results from the China Health and Retirement Longitudinal Study (CHARLS)

BACKGROUND

There has been a long-standing debate on whether depressive symptoms are associated with dementia. The aim of this study was to examine whether depressive symptoms were associated with a high risk for dementia in Chinese adults.

METHODS

A total of 13,426 Chinese adults (≥45 years old) from the China Health and Retirement Longitudinal Study (CHARLS) baseline were selected for analysis. Depressive symptoms were assessed by the Center for Epidemiologic Studies Depression Scale (CESD-10). Dementia was assessed by the Community Screening Instrument for Dementia (CSI-D). When using linear regression for sensitivity analysis, there is still a correlation between depressive symptoms and dementia.

RESULTS

Of the 13,426 respondents, the mean (SD) age was 60 (10) years old. The prevalence of depressive symptoms and dementia among participants was 38 % (n = 945) and 18.3 % (n = 2457), respectively. After fully adjusted for demographic factors, health behavior and psychological factors, living and working conditions factors, social network factors, and social policy factors, the cross-sectional analyses showed that depressive symptoms had an increased risk of dementia (OR = 1.390, 95%CI: 1.253-1.543), compared with those without depressive symptoms. In addition, sensitivity analyses of the association between depressive symptoms and dementia were unchanged when reanalyzing using linear regression.

CONCLUSIONS

In this study, depression symptoms may be associated with dementia. Regardless of whether depressive symptoms acts as a dementia risk factor or an early symptom, monitoring depressive symptoms is crucial to watch for potential dementia onset.

Bidirectional association between depressive symptoms and mild cognitive impairment over 20 years: Evidence from the Health and Retirement Study in the United States

BACKGROUND

Research examining the association between depressive symptoms and mild cognitive impairment (MCI) has yielded conflicting results. This study aimed to examine the bidirectional association between depressive symptoms and MCI, and the extent to which this bidirectional association is moderated by gender and education.

METHODS

Data come from the US Health and Retirement Study over a 20-year period (older adults aged ≥50 years). Competing-risks regression is employed to examine the association between baseline high-risk depressive symptoms and subsequent MCI (N = 9317), and baseline MCI and subsequent high-risk depressive symptoms (N = 9428). Interactions of baseline exposures with gender and education are tested.

RESULTS

After full adjustment, baseline high-risk depressive symptoms were significantly associated with subsequent MCI (SHR = 1.20, 95%CI 1.08-1.34). Participants with baseline MCI are more likely to develop subsequent high-risk depressive symptoms than those without baseline MCI (SHR = 1.16, 95%CI 1.01-1.33). Although gender and education are risk factors for subsequent depression and MCI, neither moderates the bidirectional association.

LIMITATIONS

Items used to construct the composite cognitive measure are limited; selection bias due to missing data; and residual confounding.

CONCLUSIONS

Our study found a bidirectional association between depressive symptoms and MCI. High-risk depressive symptoms are related to a higher risk of subsequent MCI; and MCI predicts subsequent high-risk depression. Though neither gender nor education moderated the bidirectional association, public health interventions crafted to reduce the risk of depression and MCI should pivot attention to older women and those with less formal education.

The association between longitudinal changes in depressive symptoms and cognitive decline among middle-aged and older Chinese adults

OBJECTIVE

Depression is associated with cognitive impairment and dementia, but few studies have been done on Chinese adults. This study evaluates the relationship between depressive symptoms status and cognitive function in middle-aged and elderly Chinese adults.

METHODS

We included 7,968 participants from the Chinese Health and Retirement Longitudinal Survey (CHRALS) with a follow-up of 4 years. Using the Center for Epidemiological Studies Depression Scale to measure depressive symptoms, with a score of 12 or more indicating elevated depressive symptoms. Adjust covariance analysis and generalized linear analysis were used to investigate the relationship between depressive symptoms status (never, new-onset, remission and persistence) and cognitive decline. Restricted cubic spline regression was used to performed the potential nonlinear associations between depressive symptoms and the change scores of cognitive functions.

RESULTS

During the 4-year follow-up, 1148 participants (14.41%) reported persistent depressive symptoms. The participants who have persistent depressive symptoms with more declines in total cognitive scores (least-square mean = -1.99, 95% CI: -3.70 to -0.27). Compared with never depressive symptoms, participants with persistent depressive symptoms experienced a faster decline in cognitive scores (β = -0.68, 95%CI: -0.98 to -0.38), and small difference (d=0.29) at follow-up. But females with new-onset depression had more cognitive decline than those with persistent depression (least-square mean _new-onset - least-square mean _persistent=-0.10), its differences in males (least-square mean _new-onset - least-square mean _persistent=0.03).

CONCLUSIONS

Participants with persistent depressive symptoms experienced a faster decline in cognitive function, but differently in men and women.

Characteristics of initial symptoms in patients with dementia with Lewy body disease

Background

Dementia with Lewy bodies (DLB) is the second most common neurodegenerative dementia. Although DLB is characterized by fluctuating cognitive impairment, some symptoms may appear before cognitive impairment, including rapid eye movement, sleep behavior disorder (RBD), psychiatric symptoms, autonomic symptoms, Parkinson's symptoms, etc. Therefore, DLB may be misdiagnosed as other diseases in its early stage.

Objective

This study aimed to investigate the characteristics of initial symptoms of DLB, which could potentially offer essential clues for the earliest diagnosis of this disorder.

Methods

A total of 239 patients with probable DLB who visited the cognitive impairment outpatient department of Tianjin Huanhu Hospital from September 2015 to March 2021 were consecutively enrolled. We retrospectively evaluated the initial symptoms of all included participants. The time of onset of initial symptoms was also assessed.

Results

The most frequent initial symptom was memory loss (53.9%), followed by psychiatric symptoms (34.7%), RBD (20.9%), parkinsonism (15.1%), and autonomic symptoms (10.1%). Significant gender and age differences existed in the initial symptoms of patients with DLB.

Conclusions

Our study elucidated the initial symptoms in patients with probable DLB. RBD was significantly more reported by men than by women, whereas women showed a higher incidence of visual and auditory hallucinations. A better understanding of the initial symptoms of DLB could lead to a more accurate diagnosis.

Depression and Increased Risk of Alzheimer's Dementia: Longitudinal Analyses of Modifiable Risk and Sex-Related Factors

OBJECTIVE

Our understanding of why older adults with depression are at increased risk of Alzheimer's disease (AD) remains incomplete. Most adults living with AD are women, and women have a near twofold lifetime risk of depression. We examined the risk of depression upon incident AD, and how sex influences this risk.

METHODS

Using the National Alzheimer's Coordinating Center database, older adults (age 50+) with normal cognition, who visited memory clinics across the United States between September 2005 and December 2019, were followed until first diagnosis of AD or loss to follow up. Multivariable survival analyses were performed to determine if recent and/or remote depression were independent risk factors for AD, if this depression-related risk exists for each sex or was moderated by sex.

RESULTS

Six hundred and fifty-two of 10,739 enrolled participants developed AD over a median follow-up of 55.3 months. Recent depression (active within the last 2 years) was independently associated with increased risk of AD (hazard ratio [HR] = 2.0; 95%CI, 1.5-2.6) while a remote history of depression was not (HR = 1.0; 95%CI, 0.7-1.5). After stratification by sex, recent depression was an independent predictor in females (HR = 2.3; 95%CI, 1.7-3.1) but not in males (HR = 1.4; 95%CI, 0.8-2.6). No interaction between recent depression and sex was observed.

CONCLUSION

Only a recent history of depression was associated with higher risk of AD. This association was significant among women only, but was not moderated by sex. Future analyses should determine if these findings extend to other populations and may be explained by variable distribution of neurobiological or other modifiable risk factors between the sexes.

Unemployment and mental health in a community population from a border city in Mexico

BACKGROUND

The constant changes in the global economy generate instability in the markets, favoring the closing of companies, dismissals of personnel, job losses. Unemployment has been associated with adverse psychological effects, serving as a predictor of poor mental health.

OBJECTIVE

The main goal was to analyze the relation between work status and mental health.

METHODS

A cross-sectional, quantitative study was carried out with a sample of community population, inhabitants of the urban area of a Mexican city. The sample consisted of 1351 participants, being 577 men (43%) and 774 women (57%) with an average age of 41.46 (SD = 17.00). The participants were selected by a quota sampling, in 13 representative points of Matamoros' city urban area. Home surveys were applied; the Spanish version of the Symptom Checklist 90 (SCL-90) was used for mental health assessment.

RESULTS

The model explaining the relation between work status and mental health (GFI) was significant (p < 0.01). Unemployment was related to higher scores in all sub-scales of psychopathologies evaluated by the SCL-90, in comparison with the rest of work status categories.

CONCLUSIONS

The unemployed, followed by housewives, presented indicators of poorer mental health, while the retired and those in strikes or lockouts showed the best mental health indexes.

Pathways Connecting Late-Life Depression and Dementia

Late-life depression is associated with significant cognitive impairment. Meta-analyses showed that depression is associated with an increased risk for Alzheimer’s disease (AD) and it might be an etiological factor for AD. Since late-life depression is often connected with cognitive impairment and dementia is usually associated with depressive symptoms, a simple diagnostic approach to distinguish between the disorders is challenging. Several overlapping pathophysiological substrates might explain the comorbidity of both syndromes. Firstly, a stress syndrome, i.e., elevated cortisol levels, has been observed in up to 70% of depressed patients and also in AD pathology. Stress conditions can cause hippocampal neuronal damage as well as cognitive impairment. Secondly, the development of a depression and dementia after the onset of vascular diseases, the profile of cerebrovascular risk factors in both disorders and the impairments depending on the location of cerebrovascular lesions, speak in favor of a vascular hypothesis as a common factor for both disorders. Thirdly, neuroinflammatory processes play a key role in the etiology of depression as well as in dementia. Increased activation of microglia, changes in Transforming-Growth-Factor beta1 (TGF-beta1) signaling, production of pro-inflammatory cytokines as well as reduction of anti-inflammatory molecules are examples of common pathways impaired in dementia and depression. Fourthly, the neurotrophin BDNF is highly expressed in the central nervous system, especially in the hippocampus, where it plays a key role in the proliferation, differentiation and the maintenance of neuronal integrity throughout lifespan. It has been associated not only with antidepressant properties but also a reduction of cognitive impairment and therefore could be involved also in AD. Another etiologic factor is amyloid accumulation, as plasma amyloid beta-42 independently predicts both late-onset depression and AD. Higher plasma amyloid beta-42 predicts the development of late onset depression and conversion to possible AD. However, clinical trials with antibodies against beta amyloid recently failed, i.e., Solanezumab, Aducanumab, and Crenezumab. An overproduction of amyloid-beta might simply reflect a form of synaptic plasticity to compensate for neuronal dysfunction in different kind of neurological and psychiatric diseases of multiple etiologies. The tau hypothesis, sex/gender specific differences, epigenetics and the gut microbiota-brain axis imply other potential common pathways connecting late-life depression and dementia. In conclusion, different potential pathophysiological links between dementia and depression highlight several specific synergistic and multifaceted treatment possibilities, depending on the individual risk profile of the patient.