Depression with melancholic features is associated with higher long-term risk for dementia

Stability of the Subtypes of Major Depressive Disorder in Older Adults and the Influence of Mild Cognitive Impairment on the Stability

OBJECTIVES

To assess 1) the longitudinal stability of the atypical, melancholic, combined atypical-melancholic and the unspecified subtypes of major depressive disorder (MDD) according to the diagnostic and statistical manual of mental disorders (DSM -IV) specifiers in older adults, and 2) the effect of mild cognitive impairment (MCI) on the stability of these subtypes.

DESIGN

Prospective cohort study with a 5.1 year-follow-up.

SETTING

Population-based cohort from Lausanne, Switzerland.

PARTICIPANTS

A total of 1,888 participants (mean age: 61.7 years, women: 69.2%) with at least two psychiatric evaluations, one after the age of 65 years.

MEASUREMENTS

Semistructured diagnostic interview to assess lifetime and 12-month DSM-IV Axis-1 disorders at each investigation and neuro-cognitive tests to identify MCI in participants aged 65 years and over. Associations between lifetime MDD status before and 12-month depression status after the follow-up were assessed using multinomial logistic regression. The effect of MCI on these associations was assessed by testing interactions between MDD subtypes and MCI status.

RESULTS

1) Associations between depression status before and after the follow-up were observed for atypical (adjusted OR [95% CI] = 7.99 [3.13; 20.44]), combined (5.73 [1.50; 21.90]) and unspecified (2.14 [1.15; 3.98]), but not melancholic MDD (3.36 [0.89; 12.69]). However, there was a certain degree of overlap across the subtypes, particularly between melancholic MDD and the other subtypes. 2) No significant interactions were found between MCI and lifetime MDD subtypes regarding depression status after follow-up.

CONCLUSION

The strong stability of the atypical subtype in particular highlights the need for identifying this subtype in clinical and research settings, given its well-documented links to inflammatory and metabolic markers.

Depression in adulthood and risk of dementia later in life: A Danish register-based cohort study of 595,828 men

BACKGROUND

Associations between depression and dementia could express a causal relationship, reverse causality or be explained by health-related factors. This study explores the association of depression and indicators of depression severity with subsequent risk of dementia while ensuring temporality and adjusting for important health-related factors.

METHOD

595,828 men from the Danish Conscription Database born in 1939-59 with register-based information on lifetime depression and covariates at age 55 years were followed in nationwide registers to identify dementia cases until 2016. Associations were analyzed using Cox proportional hazard regression models with adjustment for intelligence, education level, body mass index, and comorbidities.

RESULTS

The dementia incidence per 1000 person-years was 1.2 cases for men without prior depression and 2.1 and 3.6 cases for men who had depression identified by antidepressants and hospitalization, respectively. Compared to no prior depression, depression identified by antidepressant medication was associated with 1.94 times [95% confidence interval (CI) 1.81;2.07] higher hazard of dementia and depression identified by hospitalization with depression was associated with 2.18 [95% CI: 1.95;2.45] higher hazard of dementia. Long-term course of depression identified by antidepressant prescriptions (>20 prescriptions), was associated with 40% 95% CI: 1.23;1.59 higher hazard of dementia compared to having ≤10 prescriptions.

LIMITATIONS

This study is restricted to men and dementia cases until age 57-77 years.

CONCLUSION

Men with depression before late midlife are subject to a higher risk of dementia later in life. Clinicians should be aware of dementia symptoms in patients with a long history of depression to initiate early treatment.

The Mitochondrial Antioxidant Sirtuin3 Cooperates with Lipid Metabolism to Safeguard Neurogenesis in Aging and Depression

Neural stem cells (NSCs), crucial for memory in the adult brain, are also pivotal to buffer depressive behavior. However, the mechanisms underlying the boost in NSC activity throughout life are still largely undiscovered. Here, we aimed to explore the role of deacetylase Sirtuin 3 (SIRT3), a central player in mitochondrial metabolism and oxidative protection, in the fate of NSC under aging and depression-like contexts. We showed that chronic treatment with tert-butyl hydroperoxide induces NSC aging, markedly reducing SIRT3 protein. SIRT3 overexpression, in turn, restored mitochondrial oxidative stress and the differentiation potential of aged NSCs. Notably, SIRT3 was also shown to physically interact with the long chain acyl-CoA dehydrogenase (LCAD) in NSCs and to require its activation to prevent age-impaired neurogenesis. Finally, the SIRT3 regulatory network was investigated in vivo using the unpredictable chronic mild stress (uCMS) paradigm to mimic depressive-like behavior in mice. Interestingly, uCMS mice presented lower levels of neurogenesis and LCAD expression in the same neurogenic niches, being significantly rescued by physical exercise, a well-known upregulator of SIRT3 and lipid metabolism. Our results suggest that targeting NSC metabolism, namely through SIRT3, might be a suitable promising strategy to delay NSC aging and confer stress resilience.

Mid to late-life scores of depression in the cognitively healthy are associated with cognitive status and Alzheimer's disease pathology at death

OBJECTIVES

Early diagnosis of Alzheimer's disease (AD) is essential for early interventions. Symptoms of depression could represent a prodromal stage of AD. Very early mood alterations may help to stratify those at highest risk of late-life AD. We aim to investigate associations between baseline/longitudinal scores for depression, presence of cognitive impairment and/or AD pathology at death.

METHODS/DESIGN

Between 1991 and 2015, participants from The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age underwent 10 waves of assessment using the Geriatric Depression Scale (GDS). AD pathology at death was evaluated in 106 eligible cases. Analyses aimed to examine associations between GDS scores, cognitive status and AD pathology (as measured by Braak stage, Thal phase and CERAD).

RESULTS

Baseline GDS scores were significantly higher for those cognitively impaired at death than those cognitively normal. Significantly higher baseline GDS scores were found for those with greater Consortium to Establish a Registry for Alzheimer's Disease (CERAD) scores than those with lower CERAD scores. Similarly, significantly higher baseline GDS scores were found for those with a greater Braak stage than those with lower tau burden. These correlations remained after controlling for age at death, education and APOE ε4, but were less robust. Mean longitudinal GDS scores associated with cognition but not pathology.

CONCLUSIONS

GDS scores collected approximately 20 years before death were associated with cognitive status and AD pathology at death. We postulate that early AD-related pathological change produces raised GDS scores due to an overlapping neural basis with depression, and that this may be considered as an early diagnostic marker for AD.

The biological face of melancholia: Are there any reliable biomarkers for this depression subtype?

BACKGROUND

Melancholic depression (MD) is a subtype of Major Depression associated with more clinical severity and poorer prognosis that non-melancholic depression (NMD). The differentiation between depression subtypes is still clinical, although the identification of specific biomarkers could be useful for diagnosis and the development of new treatments. Purpose of the present manuscript is to review the biomarkers that have been associated with MD.

METHODS

We performed a bibliographic research on the main databases (PubMed, Embase, PsycInfo, Isi Web of Knowledge, Medscape, The Cochrane Library), in order to find studies that proposed biological markers for melancholic depression. A total of 14 studies met our inclusion criteria.

RESULTS

Most of studies focused on immune dysregulation. Subjects with MD show biological abnormalities than healthy controls (HC). MD might be characterized by specific biological changes and it could be associated to more severe abnormalities with respect to NMD; however especially about this latter point the available data are preliminary.

LIMITATIONS

Most available data have not been replicated; the studies focused on different biomarkers. In addition, many articles report results on a limited sample size.

CONCLUSIONS

Melancholic depression is a subtype of major depression that seems to be associated with specific alterations of different biological systems. Future studies with larger sample can confirm the results and hypothesis presented in this review.

Depressive Symptoms in the Elderly-An Early Symptom of Dementia? A Systematic Review

Background

Depression and dementia are common incapacitating diseases in old age. The exact nature of the relationship between these conditions remains unclear, and multiple explanations have been suggested: depressive symptoms may be a risk factor for, a prodromal symptom of, or a coincidental finding in dementia. They may even be unrelated or only connected through common risk factors. Multiple studies so far have provided conflicting results.

Objectives

To determine whether a systematic literature review can clarify the nature of the relation between depressive symptoms and dementia.

Methods

Using the Patient/Problem/Population, Intervention, Comparator, Outcome or PICO paradigm, a known framework for framing healthcare and evidence questions, we formulated the question “whether depressive symptoms in cognitively intact older adults are associated with a diagnosis of dementia later in life.” We performed a systematic literature review of MEDLINE and PsycINFO in November 2018, looking for prospective cohort studies examining the aforementioned question.

Results

We critically analyzed and listed 31 relevant papers out of 1,656 and grouped them according to the main hypothesis they support: depressive symptoms as a risk factor, not a risk factor, a prodromal symptom, both, or some specific other hypothesis. All but three studies used clinical diagnostic criteria for dementia alone (i.e., no biomarkers or autopsy confirmation). Several studies contain solid arguments for the hypotheses they support, yet they do not formally contradict other findings or suggested explanations and are heterogeneous.

Conclusions

The exact nature of the relationship between depressive symptoms and dementia in the elderly remains inconclusive, with multiple studies supporting both the risk factor and prodromal hypotheses. Some provide arguments for common risk factors. It seems unlikely that there is no connection at all. We conclude that at least in a significant part of the patients, depressive symptoms and dementia are related. This may be due to common risk factors and/or depressive symptoms being a prodromal symptom of dementia and/or depression being a risk factor for dementia. These causal associations possibly overlap in some patients. Further research is warranted to develop predictive biomarkers and to develop interventions that may attenuate the risk of “conversion” from depressive symptoms to dementia in the elderly.

Personality disorders characterized by anxiety predict Alzheimer's disease in women: A case-control studies

This research is geared toward the evaluation of current and pre-morbid personality psychopathology in Alzheimer's disease (AD). The study was conducted with four groups who were administered the Personality Diagnostic Questionnaire-4+, mainly in the form of individual interviews. Current measurement: AD Group, 44 female participants (M = 81.36 years); Control Group, 80 female participants from the population at large (M = 75.84 years). Pre-morbid measurement: AD Group Informants (n = 40); Control Group Informants (n = 42). The incidence of all clusters in clinical state are significant, and Cluster B incidence in pre-morbidity is evidenced. Cluster C is highlighted throughout the life course as a predictor. Logistic regression analyses showed that schizotypical, narcissistic, avoidant, obsessive-compulsive, pre-morbid schizotypical, pre-morbid histrionic, and pre-morbid obsessive-compulsive personality disorders, predicted the presence of AD diagnosis, accounting for 49% of the variance. These findings are relevant to research relating personality and psychopathology in Alzheimer's disease.

Help-seeking experiences of older adults with a diagnosis of moderate depression

Depression is the most prevalent mental illness among older adults. However, help-seeking by older adults is frequently delayed, resulting in longer duration of untreated symptoms, poorer health outcomes, and consequent higher healthcare use. Early help-seeking and access to appropriate support benefits individuals, while providing better outcomes from health systems constrained by limited resources. The aim of this study, which is abstracted from a larger study, was to identify the factors that inhibited and enabled formal help-seeking in older adults with a diagnosis of moderate depression. Corbin and Strauss' approach to grounded theory informed data collection and analysis. Two themes and related subthemes concerning help-seeking barriers and facilitators were abstracted from the data. Help-seeking barriers were attributable to stigma, self-motivation, accessing formal support, ageism, and difficulty obtaining an initial diagnosis. Help-seeking facilitators were accepting personal responsibility, mental health literacy, therapeutic alliances, and informal support. Findings have implications for the role of mental health nurses, who are well-placed to provide support to community-based older adults with depression. More broadly, mental health nurses and other clinicians should seek to reduce help-seeking barriers and implement ways to facilitate help-seeking in this cohort.

Depressive vulnerability in women with Alzheimer's disease: Relationship with personality traits and abnormal personality dimensions

BACKGROUND

This study sought to determine the evaluation of current and pre-morbid depressive vulnerability dimensions in Alzheimer's disease. Sidney Blatt´s personality developmental perspective, the Five-Factor model and Axis II personality disorders were taken as references.

METHODS

The study was conducted with two groups which were assessed using the Depressive Experiences Questionnaire, the NEO-FFI and the Personality Diagnostic Questionnaire-4+, in the form of individual interview sessions. Current personality measure: Alzheimer's disease Group, consisting of 44 female participants (M_Age= 81.36 years); Pre-morbid personality measure: Alzheimer's disease Group Informants (n = 40).

RESULTS

Self-Criticism personality vulnerability is a general indicator of psychopathology. In pre-morbidity, Neuroticism (β = 0.41), Agreeableness (β = -0.63) and Conscientiousness (β = -0.08) predicted Self-Criticism, explaining 64% of the variance; additionally, Self-Criticism (β = 0.72) and Neediness (β = 2.05) predicted the PDQ-4+ total, explaining 58% of the variance. In terms of current personality, the PDQ-4+ total was predicted by Self-Criticism (β = 0.55), explaining 30% of the variance.

LIMITATIONS

The small size of the samples, especially since it is difficult to access individuals diagnosed with AD at the onset or in its early stages; measuring personality changes by means of retrospective assessment by proxies may have introduced some memory bias.

CONCLUSIONS

These findings are relevant to research relating depressive vulnerability to personality traits and psychopathology in Alzheimer's disease.

Anxiety as a risk factor of Alzheimer's disease and vascular dementia

BACKGROUND

The aetiology of dementia is not yet fully understood. Stress can have a damaging effect on brain health. The prognostic effect of anxiety is still unclear regarding Alzheimer's disease as well as vascular dementia.AimsTo explore the association between anxiety and future dementia.

METHOD

Medline, PsycINFO, CINAHL, Web of Science and ALOIS were searched for publications up to 12 January 2018. Longitudinal studies with a follow-up of at least 2 years were included, if the trait or state anxiety had been assessed at baseline. Studies with cognitive impairment at baseline were not included. We used a random effects model to calculate the pooled time to Alzheimer's disease and incidence of vascular dementia.

RESULTS

Anxiety predicts risk of Alzheimer's disease (n = 26 193 out of seven studies, hazard ratio1.53, 95% CI 1.16-2.01, P < 0.01) and vascular dementia (n = 4916 out of two studies, odds ratio1.88, 95% CI 1.05-3.36, P < 0.01). The pooled hazard ratio regarding risk of Alzheimer's disease was still significant when excluding studies with critical risk of bias (n = 14 110 out of six studies, hazard ratio 1.35, 95% CI 1.08-1.70, P < 0.01).

CONCLUSIONS

Anxiety is a risk factor for both types of dementia. The temporal and functional relation between anxiety and dementia needs investigation in future studies. The protective value of treating anxiety should be explored further.Declaration of interestNone.