Relationship between cognition, magnetic resonance white matter hyperintensities, and cardiovascular autonomic changes in late-life depression

Presurgical depressive symptom and anaesthetic requirements in patients undergoing surgery for malignant and non-malignant conditions: A prospective observational cohort study

The incidence and magnitude of depression are rarely assessed during preanaesthetic evaluation. The shared physiological mechanisms of depression and anaesthetic drugs are likely to alter the pharmacodynamics of propofol. Therefore, the study aimed to evaluate the burden of presurgical depression and its effect on propofol consumption during anaesthesia. This prospective, observational, cross-sectional, analytical study included adult patients (> 18 years) undergoing surgery. During the preoperative period, depressive symptoms were evaluated by the psychiatrist on 9-point Patient Health Questionnaire-9 (PHQ-9). The propofol requirements were recorded during anaesthesia and compared with those for patients without depression. One hundred and seventy-four patients (87 patients each with and without cancer) underwent presurgical evaluation. The prevalence of depression (>4 Patient Health Questionnaire-9) and moderate to severe depression (>9 PHQ-9) among patients with cancer was 58.6% and 35.6%, respectively. The prevalence of depression (>4 PHQ-9) and moderate to severe depression (>9 PHQ-9) among patients without cancer was 18.4% and 3.4%, respectively. In the cancer group, propofol requirement was significantly lower (114.7 ± 22.9mg vs. 126.4 ± 24.3mg; p = 0.025) in patients with depression than that in those without depression. In conclusion, the burden of depression during the preanaesthetic period among patients with cancer is substantial, and depression reduces propofol requirement during surgery.

Prefrontal activity and heart rate variability during cognitive tasks may show different changes in young and older adults with and without mild cognitive impairment

Background

Age-related decline in cognitive function is often linked to changed prefrontal cortex (PFC) activity and heart rate variability (HRV). Mild cognitive impairment (MCI), a transitional stage between normal aging and dementia, might have further degeneration beyond aging. This study aimed to investigate the differences between young and older adults with or without MCI in cognitive functions, task-induced PFC activation and HRV changes.

Methods

Thirty-one healthy young adults (YA), 44 older adults (OA), and 28 older adults with MCI (OA-MCI) were enrolled and compared in this cross-sectional study. Each participant received a one-time assessment including cognitive and executive functions, as well as the simultaneous recording of PFC activity and HRV during a cognitive task paradigm.

Results

We observed age-related decrease in global cognitive functions, executive functions, HRV, and increase in PFC activity. The MCI further deteriorated the global cognitive and executive performances, but not the HRV or the prefrontal activation.

Conclusion

Older people showed lower performances in general cognitive function and executive function, compensatory increase of PFC activity, and reduced HRV. Older people with MCI had further deterioration in cognitive performance, but not in PFC activation and HRV.

Heart Rate Variability and Cognition: A Narrative Systematic Review of Longitudinal Studies

BACKGROUND

Heart rate variability (HRV) is a reliable and convenient method to assess autonomic function. Cross-sectional studies have established a link between HRV and cognition. Longitudinal studies are an emerging area of research with important clinical implications in terms of the predictive value of HRV for future cognition and in terms of the potential causal relationship between HRV and cognition. However, they have not yet been the objective of a systematic review. Therefore, the aim of this systematic review was to investigate the association between HRV and cognition in longitudinal studies.

METHODS

The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Embase, PsycINFO and PubMed databases were searched from the earliest available date to 26 June 2023. Studies were included if they involved adult human subjects and evaluated the longitudinal association between HRV and cognition. The risk of bias was assessed with the Newcastle-Ottawa Scale for Cohort Studies. The results were presented narratively.

RESULTS

Of 14,359 records screened, 12 studies were included in this systematic review, with a total of 24,390 participants. Two thirds of the studies were published from 2020 onwards. All studies found a longitudinal relationship between HRV and cognition. There was a consistent association between higher parasympathetic nervous system (PNS) activity and better cognition, and some association between higher sympathetic nervous system activity and worse cognition. Also, higher PNS activity persistently predicted better executive functioning, while data on episodic memory and language were more scant and/or controversial.

CONCLUSIONS

Our results support the role of HRV as a biomarker of future cognition and, potentially, as a therapeutic target to improve cognition. They will need confirmation by further, more comprehensive studies also including unequivocal non-HRV sympathetic measures and meta-analyses.

Altered topological properties of functional brain networks in patients with first episode, late-life depression before and after antidepressant treatment

Objectives

To preliminarily explore the functional activity and information integration of the brains under resting state based on graph theory in patients with first-episode, late-life depression (LLD) before and after antidepressant treatment.

Methods

A total of 50 patients with first-episode LLD and 40 non-depressed controls (NCs) were recruited for the present research. Participants underwent the RBANS test, the 17-item Hamilton depression rating scale (HAMD-17) test, and resting-state functional MRI scans (rs-fMRI). The RBANS test consists of 12 sub-tests that contribute to a total score and index scores across the five domains: immediate memory, visuospatial/constructional, language, attention, and delayed memory. Escitalopram or sertraline was adopted for treating depression, and the dosage of the drug was adjusted by the experienced psychiatrists. Of the 50 LLD patients, 27 cases who completed 6-month follow-ups and 27 NCs matched with age, sex, and education level were included for the final statistical analysis.

Results

There were significant differences in RBANS total score, immediate memory, visuospatial/constructional, language, attention, and delayed memory between LLD baseline group and NCs group (P < 0.05). Considering the global attribute indicators, the clustering coefficient of global indicators was lower in the LLD baseline group than in the NCs group, and the small-world attribute of functional brain networks existed in all three groups. The degree centrality and node efficiency of some brains were lower in the LLD baseline group than in the NCs group. After 6 months of antidepressant therapy, the scores of HAMD-17, immediate memory, language, and delayed memory in the LLD follow-up group were higher than those in the LLD baseline group. Compared with the LLD baseline group, the degree centrality and node efficiency of some brains in the cognitive control network were decreased in the LLD follow-up group.

Conclusions

The ability to integrate and divide labor of functional brain networks declines in LLD patients and linked with the depression severity. After the relief of depressive symptoms, the small-world attribute of functional brain networks in LLD patients persists. However, the information transmission efficiency and centrality of some brain regions continue to decline over time, perhaps related to their progressive cognitive impairment.

Autonomic function predicts cognitive decline in mild cognitive impairment: Evidence from power spectral analysis of heart rate variability in a longitudinal study

Background

Despite the emerging clinical relevance of heart rate variability (HRV) as a potential biomarker of cognitive decline and as a candidate target for intervention, there is a dearth of research on the prospective relationship between HRV and cognitive change. In particular, no study has addressed this issue in subjects with a diagnosis of cognitive status including cognitive impairment.

Objective

To investigate HRV as a predictor of cognitive decline in subjects with normal cognition (NC) or Mild Cognitive Impairment (MCI). Specifically, we tested the literature-based hypothesis that the HRV response to different physical challenges would predict decline in different cognitive domains.

Methods

This longitudinal study represents the approximately 3-year follow-up of a previous cross-sectional study enrolling 80 older outpatients (aged ≥ 65). At baseline, power spectral analysis of HRV was performed on five-minute electrocardiographic recordings at rest and during a sympathetic (active standing) and a parasympathetic (paced breathing) challenge. We focused on normalized HRV measures [normalized low frequency power (LFn) and the low frequency to high frequency power ratio (LF/HF)] and on their dynamic response from rest to challenge (Δ HRV). Extensive neuropsychological testing was used to diagnose cognitive status at baseline and to evaluate cognitive change over the follow-up via annualized changes in cognitive Z-scores. The association between Δ HRV and cognitive change was explored by means of linear regression, unadjusted and adjusted for potential confounders.

Results

In subjects diagnosed with MCI at baseline a greater response to a sympathetic challenge predicted a greater decline in episodic memory [adjusted model: Δ LFn, standardized regression coefficient (β) = −0.528, p = 0.019; Δ LF/HF, β = −0.643, p = 0.001] whereas a greater response to a parasympathetic challenge predicted a lesser decline in executive functioning (adjusted model: Δ LFn, β = −0.716, p < 0.001; Δ LF/HF, β = −0.935, p < 0.001).

Conclusion

Our findings provide novel insight into the link between HRV and cognition in MCI. They contribute to a better understanding of the heart-brain connection, but will require replication in larger cohorts.

Effect of esketamine on perioperative depressive symptoms in major surgery patients (PASSION II): study protocol for a randomised controlled trial

INTRODUCTION

Depressive symptoms are common for patients undergoing major surgery and may worsen their mental health and lead to poor clinical outcomes. It is essential to seek a safe rapid-acting treatment for relieving moderate-to-severe depressive symptoms in patients undergoing major surgery.

METHODS AND ANALYSIS

This study is a randomised, placebo-controlled and double-blinded trial aiming to determine the effect of esketamine on moderate-to-severe depressive symptoms in patients undergoing major surgery. Five hundred and sixty-four participants, aged 18-65 years old, undergoing major surgery will be randomly allocated into the esketamine and placebo groups at a 1:1 ratio. Esketamine or placebo will be given intravenously at the same speed on suturing the incision by anaesthesiologists in charge who are blinded to the randomisation. In the esketamine group, the total dosage of esketamine will be 0.2 mg/kg body weight. To estimate the efficacy and safety endpoints, blinded evaluation by trained researchers will be completed at 3 days, 5 days, 1 month, 3 months and 6 months after surgery. The primary outcome is the remission rate at the third postoperative day. The secondary outcomes include depression-related scores, severe pain events and safety-related endpoints such as psychotic symptoms, manic symptoms and dissociative symptoms.

ETHICS AND DISSEMINATION

This study was approved by the Institutional Review Board of Beijing Tiantan Hospital, Capital Medical University, Beijing, China on 30 October 2020 (KY-2020-058-02). This trial is designed to explore whether the administration of esketamine could improve the mental health of patients with depressive symptoms undergoing major surgery. The conclusions of this study will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04425473.

Brain-based mechanisms of late-life depression: Implications for novel interventions

Late-life depression (LLD) is a particularly debilitating illness. Older adults suffering from depression commonly experience poor outcomes in response to antidepressant treatments, medical comorbidities, and declines in daily functioning. This review aims to further our understanding of the brain network dysfunctions underlying LLD that contribute to disrupted cognitive and affective processes and corresponding clinical manifestations. We provide an overview of a network model of LLD that integrates the salience network, the default mode network (DMN) and the executive control network (ECN). We discuss the brain-based structural and functional mechanisms of LLD with an emphasis on their link to clinical subtypes that often fail to respond to available treatments. Understanding the brain networks that underlie these disrupted processes can inform the development of targeted interventions for LLD. We propose behavioral, cognitive, or computational approaches to identifying novel, personalized interventions that may more effectively target the key cognitive and affective symptoms of LLD.

Baroreceptor Modulation of the Cardiovascular System, Pain, Consciousness, and Cognition

Baroreceptors are mechanosensitive elements of the peripheral nervous system that maintain cardiovascular homeostasis by coordinating the responses to external and internal environmental stressors. While it is well known that carotid and cardiopulmonary baroreceptors modulate sympathetic vasomotor and parasympathetic cardiac neural autonomic drive, to avoid excessive fluctuations in vascular tone and maintain intravascular volume, there is increasing recognition that baroreceptors also modulate a wide range of non-cardiovascular physiological responses via projections from the nucleus of the solitary tract to regions of the central nervous system, including the spinal cord. These projections regulate pain perception, sleep, consciousness, and cognition. In this article, we summarize the physiology of baroreceptor pathways and responses to baroreceptor activation with an emphasis on the mechanisms influencing cardiovascular function, pain perception, consciousness, and cognition. Understanding baroreceptor-mediated effects on cardiac and extra-cardiac autonomic activities will further our understanding of the pathophysiology of multiple common clinical conditions, such as chronic pain, disorders of consciousness (e.g., abnormalities in sleep-wake), and cognitive impairment, which may result in the identification and implementation of novel treatment modalities. © 2021 American Physiological Society. Compr Physiol 11:1373-1423, 2021.

Neural substrates for late-life depression: A selective review of structural neuroimaging studies

Recent neuroimaging studies have characterized the pathophysiology of late-life depression (LLD) as a dysfunction of the brain networks involved in the regulation of emotion, motivational behavior, cognitive control, executive function, and self-referential thinking. In this article, we reviewed LLD-associated structural neuroimaging markers such as white matter hyperintensity (WMH), white matter integrity measured by diffusion tensor imaging, cortical and subcortical volumes, and cortical thickness, which may provide a structural basis for brain network dysfunction in LLD. LLD was associated with greater severity or volumes of deep, periventricular, or overall WMH and with decreased white matter integrity in the brain regions belonging to the fronto-striatal-limbic circuits and reduced white matter tract integrity which connects these circuits, such as the cingulum, corpus callosum, or uncinate fasciculus. Decreased volumes or cortical thickness in the prefrontal cortex, orbitofrontal cortex, anterior and posterior cingulate cortex, several temporal and parietal regions, hippocampus, amygdala, striatum, thalamus, and the insula were associated with LLD. These structural neuroimaging findings were also associated with cognitive dysfunction, which is a prominent clinical feature in LLD. Several structural neuroimaging markers including the WMH burden, white matter integrity, and cortical and subcortical volumes predicted antidepressant response in LLD. These structural neuroimaging findings support the hypothesis that disruption of the brain networks involved in emotion regulation and cognitive processing by impaired structural connectivity is strongly associated with the pathophysiology of LLD.

Autonomic function in amnestic and non-amnestic mild cognitive impairment: spectral heart rate variability analysis provides evidence for a brain-heart axis

Mild cognitive impairment (MCI) is a heterogeneous syndrome with two main clinical subtypes, amnestic (aMCI) and non-amnestic (naMCI). The analysis of heart rate variability (HRV) is a tool to assess autonomic function. Cognitive and autonomic processes are linked via the central autonomic network. Autonomic dysfunction entails several adverse outcomes. However, very few studies have investigated autonomic function in MCI and none have considered MCI subtypes or the relationship of HRV indices with different cognitive domains and structural brain damage. We assessed autonomic function during an active orthostatic challenge in 253 oupatients aged ≥ 65, [n = 82 aMCI, n = 93 naMCI, n = 78 cognitively normal (CN), neuropsychologically tested] with power spectral analysis of HRV. We used visual rating scales to grade cerebrovascular burden and hippocampal/insular atrophy (HA/IA) on neuroimaging. Only aMCI showed a blunted response to orthostasis. Postural changes in normalised low frequency (LF) power and in the LF to high frequency ratio correlated with a memory test (positively) and HA/IA (negatively) in aMCI, and with attention/executive function tests (negatively) and cerebrovascular burden (positively) in naMCI. These results substantiate the view that the ANS is differentially impaired in aMCI and naMCI, consistently with the neuroanatomic substrate of Alzheimer's and small-vessel subcortical ischaemic disease.

Mechanisms Linking White Matter Lesions, Tract Integrity, and Depression in Alzheimer Disease

OBJECTIVE

Late-life depression involves the disconnection of white matter tracts that regulate mood. A pathogenic link between poor tract integrity and depressive symptoms is believed to be white matter lesions (WML), however the mechanisms linking tract integrity, WML, and depression remains unexplored. The authors sought to identify whether the association between reduced tract integrity and depressive symptoms is mediated by WML in patients with Alzheimer disease (AD), and whether individual characteristics moderate this effect.

METHODS

This was a cross-sectional study in a tertiary memory clinic. A total of 91 patients with mild AD and 79 healthy elderly, comparable in depressive symptoms, white matter hyperintensities (WMH) volume, cardiovascular risk, age, and sex were chosen. Tract integrity was assessed using diffusion tensor imaging, WML were indexed as WMH, measured using fluid-attenuation inversion recovery imaging, and depressive symptoms were measured with the informant-based Geriatric Depression Scale.

RESULTS

In patients with mild AD, reduced tract integrity in right hemispheric cortical-subcortical tracts and the genu of the corpus callosum was moderately associated with depressive symptoms. This association was fully mediated by WML. Moderation analysis indicated that old age strengthened the association between all tracts and depressive symptoms, as mediated by WML. In cognitively healthy elderly, neither tracts nor WML were related to depressive symptoms.

CONCLUSION

Reduced tract integrity may be important but not sufficient for the manifestation of depressive symptoms in mild AD. Instead, WML may drive the pathogenic link between reduced tract integrity and depressive symptoms.

Cerebrovascular Disease Is a Risk for Getting Lost Behavior in Prodromal Dementia

Cerebrovascular disease (CVD) contributes to spatial navigation deficits; however, the everyday outcomes of this association remain unexplored. We investigated whether CVD was a risk for getting lost behavior (GLB) in elderly with mild cognitive impairment (MCI) and mild Alzheimer disease (AD). Getting lost behavior was assessed using a semistructured clinical interview and was associated with white matter lesions (WMLs) in patients with MCI. Specifically, right occipital WMLs increased the odds of GLB by 12 times (P = .03) and right temporal WMLs increased the odds of GLB by 4 times (P = .01), regardless of age, gender, global cognitive impairment, and occipital or medial temporal gray matter atrophy. Hypertension increased the risk of GLB in MCI by contributing to the burden of WMLs. White matter lesions were not associated with GLB in mild AD. Our findings suggest that interventions aimed at reducing GLB in prodromal dementia may involve preventing WMLs by optimizing hypertension control.

Confining the Concept of Vascular Depression to Late-Onset Depression: A Meta-Analysis of MRI-Defined Hyperintensity Burden in Major Depressive Disorder and Bipolar Disorder

Background: The vascular depression hypothesis emphasizes the significance of vascular lesions in late-life depression. At present, no meta-analytic model has investigated whether a difference in hyperintensity burden compared to controls between late-life and late-onset depression is evident. By including a substantial number of studies, focusing on a meaningful outcome measure, and considering several moderating and control variables, the present meta-analysis investigates the severity of hyperintensity burden in major depressive disorder (MDD) and bipolar disorder (BD). A major focus of the present meta-analysis refers to the role of age at illness onset. It is analyzed whether late-onset rather than late-life depression characterizes vascular depression. Method: In total, 68 studies were included in the meta-analysis and a multilevel random effects model was calculated using Hedges' g as the effect size measure. Results: The severity of hyperintensity burden was significantly greater in the patient group compared to the control group. This effect was evident regarding the whole patient group (g = 0.229) as well as both depression subgroups, with a significantly greater effect in BD (g = 0.374) compared to MDD (g = 0.189). Hyperintensity burden was more pronounced in late-onset depression than in early-onset depression or late-life depression. A considerable heterogeneity between the included studies was observed, which is reflected by the large variability in effects sizes. Conclusion: In conclusion, the present meta-analysis underscores the association of hyperintensities with MDD and BD. Especially late-onset depression is associated with an increased hyperintensity burden, which is in line with the vascular depression hypothesis. The results suggest that it might be more feasible to confine the concept of vascular depression specifically to late-onset depression as opposed to late-life depression. Further research is needed to understand the causal mechanisms that might underlie the relation between hyperintensity burden and depression.

The impact of white matter hyperintensities on the structural connectome in late-life depression: Relationship to executive functions

BACKGROUND

White matter hyperintensities (WMH) represent ischemic white matter damage in late-life depression (LLD) and are associated with cognitive control dysfunction. Understanding the impact of WMH on the structural connectivity of gray matter and the cognitive control correlates of WMH-related structural dysconnectivity can provide insight into the pathophysiology of LLD.

METHODS

We compared WMH burden and performance on clinical measures of cognitive control in patients with LLD (N = 44) and a control group of non-depressed older adults (N = 59). We used the Network Modification (NeMo) Tool to investigate the impact of WMH on structural dysconnectivity in specific gray matter regions, and how such connectivity was related to cognitive control functions.

RESULTS

Compared to the control group, LLD participants had greater WMH burden, poorer performance on Trail Making Test (TMT) A & B, and greater self-reported dysexecutive behavior on the Frosntal Systems Behavior Scale-Executive Function subscale (FrSBe-EF). Within the LLD group, disrupted connectivity in the left supramarginal gyrus, paracentral lobule, thalamus, and pallidum was associated with psychomotor slowing (TMT-A). Altered connectivity in the left supramarginal gyrus, paracentral lobule, precentral gyrus, postcentral gyrus, thalamus, and pallidum was associated with poor attentional set-shifting (TMT-B). A follow-up analysis that isolated set-shifting ability (TMT-B/A ratio) confirmed the association with dysconnectivity in the bilateral paracentral lobule, right thalamus, left precentral gyrus, postcentral gyrus, and pallidum; additionally, it revealed associations with dysconnectivity in the right posterior cingulate, and left anterior cingulate, middle frontal cortex, and putamen.

CONCLUSIONS

In LLD, WMH are associated with region-specific disruptions in cortical and subcortical gray matter areas involved in attentional aspects of cognitive control systems and sensorimotor processing, which in turn are associated with slower processing speed, and reduced attentional set-shifting.

CLINICAL TRIALS REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT01728194.

Depression related cerebral pathology and its relationship with cognitive functioning: A systematic review

BACKGROUND

Depression's relationship with cerebral abnormalities and cognitive decline is temporally dynamic. Despite clear clinical utility, understanding depression's effect on cerebral structures, cognitive impairment and the interaction between these symptoms has had limited consideration.

METHODS

This review summarised studies examining a clinical depression diagnosis or validated scales measuring depressive symptoms, data concerning amyloid-beta (Aβ) levels, brain structure and function focusing on hippocampal alterations, or white matter hyperintensities (WMH), and at least one validated neuropsychological test. Online database searches of: PsycINFO, EMBASE, MEDLINE, and Scopus were conducted to identify potential articles.

RESULTS

While depression was consistently associated with cross-sectionally cognitive decline across multiple domains, the neuropathological basis of this dysfunction remained unclear. Hippocampal, frontal, and limbic dysfunction as well as cortical thinning, WMH, and Aβ burden all provide inconsistent findings, likely due to depression subtypes. The consistency of these findings additionally decreases when examining this relationship longitudinally, as these results are further confounded by pre-dementia states. The therapeutic interventions examined were more efficacious in the younger compared with the older samples, who were characterised by greater WMH and Aβ burden.

LIMITATIONS

The limited number of longitudinal and interventional studies in addition to the heterogeneity of the samples restricts their generalisability.

CONCLUSIONS

Symptomatological differences between early-onset and late-onset depression (EOD and LOD) appear crucial in understanding whether late-life depression is the primary or secondary source of cerebral pathology. Though severe cognitive impairments and clearer neuropathological underpinnings are more characteristic of LOD than EOD, the inconsistency of valid biomarkers remains problematic.

Serial position effects differ between Alzheimer's and vascular features in mild cognitive impairment

Individuals with mild cognitive impairment (MCI) exhibit varying serial position effect (SPE) performances. The relationship between SPE performance in word list recall and clinical, genetic, and neuroimaging features of MCI requires elucidation. 119 MCI and 68 cognitively normal (CN) participants underwent cognitive assessment, apolipoprotein E (ApoE) genotyping, and volumetric MRI brain scans processed via voxel-based morphometry. A 10-word recall task was used to assess SPE performance in relation to recency and primacy recall. MCI participants were classified as having Good SPE performance (high primacy and recency, Good SPE) or Poor SPE performance (low primacy only, LP-SPE; low recency only, LR-SPE; or both low, Low SPE). Poor SPE participants had reduced grey matter (GM) volumes and increased white matter hyperintensities (WMH) volumes. Participants with LP-SPE demonstrated reduced hippocampal GM volumes and were more likely to be ApoE ε4 carriers. LR-SPE was associated with higher WMH volumes. Presence of both greater WMH volumes and ApoE ε4 resulted in Low SPE. LP-SPE MCI participants had features typical of Alzheimer's disease. LR-SPE MCI was associated with increased WMH volumes, likely representing vascular pathology. SPE profiles are associated with distinct clinical patterns of MCI pathophysiology and could have potential as a clinical marker.

Orthostatic hypotension in patients with late-life depression: Prevalence and validation of a new screening tool

OBJECTIVES

The objective of this study was to assess the prevalence of orthostatic hypotension (OH) in a sample of late life depression (LLD) patients and to determine the validity of a standardized questionnaire, the Orthostatic Hypotension Questionnaire (OHQ). Secondarily, we wished to assess variables associated with OH.

METHODS

We conducted a cross-sectional study on 82 consecutive geriatric outpatients presenting with LLD. OH was defined as a fall in systolic blood pressure of greater than 20 mm Hg and/or 10 mm Hg on diastolic blood pressure on an orthostatic stress test from sitting to standing. Logistic regressions were used to identify factors associated with OH.

RESULTS

The prevalence of OH as measured on the orthostatic stress test and on the OHQ was 28% and 57%, respectively. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the OHQ were 69.6% (95% CI 47%-87%), 47.5% (95%CI 34%-61%), 0.54 (95% CI: 0.43-0.64), 34% (95%CI 21%-49%), and 80% (95%CI 63%-92%), respectively. Females were more likely to have OH (OR: 3.96, 95%CI 1.06-14.89, P = .041), and those married or in a common-law relationship were less likely to have OH (OR: 0.25, 95% CI 0.08-0.72, P = .011).

CONCLUSIONS

OH is common in patients with LLD conferring them a risk of gait instability and falls. Females had a higher risk of having OH while participants who were married or in a common-law relationship were less likely to have OH. Although the OHQ is a quick to administer paper-based screening test, it did not show adequate diagnostic accuracy in patients with LLD seen in a routine psychiatry clinic.

Peak exercise stroke volume effects on cognitive impairment in community-dwelling people with preserved ejection fraction

AIMS

The association of vascular dysfunction and amyloid beta deposition attracted attentions for its relationship with cognitive decline. Previous studies show the correlation between the declined cardiac function and the cognitive impairment. In the present study, we analysed the association between cognitive functions and cardiac parameters in community-dwelling people with preserved ejection fraction without heart failure.

METHODS AND RESULTS

Subjects were 108 Japanese community-dwelling middle-aged and older adults with preserved ejection fraction (25 men and 83 women; mean age 74.7 years). Cardiac functional parameters at rest were assessed with B-type natriuretic peptide and echocardiography. The cardiopulmonary exercise test was used to test these parameters during exercise. Cognitive function was assessed with the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Other indices were assessed biochemically, physiologically, and physically. There were significant correlations between MoCA-J score and age (r = -0.388), peak oxygen uptake (VO₂ , r = 0.201), peak VO₂ /heart rate (HR, r = 0.243), peak VO₂ /weight (r = 0.244), peak metabolic equivalents (r = 0.244), usual walking speed (r = -0.200), and the Timed Up and Go test (r = -0.230). Multiple linear regression analysis showed peak VO₂ /HR was an independent determinant of MoCA-J score after adjusting for potential confounders (B = 0.424). After 6 months of exercise training with 64 subjects, we found that the per cent change of peak VO₂ /HR was related to the per cent change of MoCA-J score (r = 0.296).

CONCLUSIONS

These results suggested that peak VO₂ /HR (an index of stroke volume at peak exercise) might be associated with cognitive impairment based on the vascular cascade hypothesis.

BOLD activation of the ventromedial prefrontal cortex in patients with late life depression and comparison participants

ABSTRACTThe ventromedial prefrontal cortex's (vMPFC) role in regulating emotions in late life depression (LLD) remains unclarified. We assessed vMPFC activation in an emotional valence blood oxygenation level-dependent (BOLD) functional magnetic neuroimaging (fMRI) task and related the findings to extent of white matter hyperintensities (WMH). Sixteen participants with mild to moderate LLD were compared to 14 similar aged comparison participants. Participants in the scanner viewed words matched for length and arousal, indicated the perceived valence by pressing one of the three buttons i.e. "positive, negative, or neutral." WMH volume was greater in LLD participants than comparison participants. There were no differences in activations between groups to any valence contrast. Female LLD participants showed greater activation for negative versus positive and negative versus neutral words as compared to female comparison participants. Female LLD participants respond differently to emotionally laden words compared to comparison participants. WMH could play a role in etiopathology of emotional perception in female LLD participants.

White Matter Lesions are Associated with Specific Depressive Symptom Trajectories among Incident Depression and Dementia Populations: Three-City Dijon MRI Study

OBJECTIVE

Evidence is mixed as to whether periventricular or deep white matter hyperintensities (WMHs) increase the risk for depressive symptoms, partly because of heterogeneity in depression measurement, short follow-up, and confounding by prodromal dementia. The study objective was to evaluate WMH volume in relation to discrete depressive symptoms over 10 years, stratifying by incident depression and dementia.

METHODS

In this prospective longitudinal cohort study of a representative population sample from Dijon, France, 1,440 participants aged 65-80 years (median age: 72 years; 59.5% women) without depression, dementia, or stroke at baseline were studied. Baseline T2-weighted images were obtained in a 1.5-T scanner to quantify WMHs (log cm³). Clinic visits were performed up to five times in a 10-year period to assess incident neurologic diseases and comorbidities. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale and converted to factor z scores, representing somatic symptoms, depressed affect, low positive affect, and interpersonal problems.

RESULTS

Periventricular WMH volume was uniquely associated with low positive affect among incident depression cases (β = 0.15; 95% confidence interval [CI]: 0.02-0.29; p = 0.026). Deep WMH volume was uniquely associated with depressed affect among incident dementia cases (β = 0.36; 95% CI: 0.05-0.68; p = 0.025). WMH volume (periventricular, deep, and total) was associated with interpersonal problems among persons who developed dementia with depression.

CONCLUSION

The findings highlight that regional WMH volumes and specific depressive symptoms have clinical and prognostic relevance to help differentiate between persons at risk for depression and dementia.

Strategies for dementia prevention: latest evidence and implications

Dementia is a common and debilitating syndrome with enormous impact on individuals and societies. Preventing disease onset or progression would translate to public health and societal benefits. In this review, we discuss the latest evidence on interventions that may show promise for the prevention of cognitive decline. We appraise existing evidence primarily drawn from randomized controlled trials, systematic reviews, and meta-analyses, but also highlight observational studies in humans and relevant work in model organisms. Overall, there is currently limited evidence to support a cause-effect relationship between any preventive strategy and the development or progression of dementia. However, studies to date suggest that a multifactorial intervention comprising regular exercise and healthy diet, along with the amelioration of vascular risk factors, psychosocial stress, and major depressive episodes may be most promising for the prevention of cognitive decline. We discuss the challenges, future directions, and implications of this line of research.

Relationship between cognitive function and regulation of cerebral blood flow

Ageing is the primary risk factor for cognitive deterioration. Given that the cerebral blood flow (CBF) or regulation of cerebral circulation is attenuated in the elderly, it could be expected that ageing-induced cognitive deterioration may be affected by a decrease in CBF as a result of brain ischemia and energy depletion. CBF regulation associated with cerebral metabolism thus likely plays an important role in the preservation of cognitive function. However, in some specific conditions (e.g. during exercise), change in CBF does not synchronize with that of cerebral metabolism. Our recent study demonstrated that cognitive function was more strongly affected by changes in cerebral metabolism than by changes in CBF during exercise. Therefore, it remains unclear how an alteration in CBF or its regulation affects cognitive function. In this review, I summarize current knowledge on previous investigations providing the possibility of an interaction between regulation of CBF or cerebral metabolism and cognitive function.

Effects of levomilnacipran extended-release on major depressive disorder patients with cognitive impairments: post-hoc analysis of a phase III study

Performance-based cognitive data were collected using the Cognitive Drug Research System in a study of levomilnacipran extended-release (ER) 40-120 mg/day (NCT01034462) in adults with major depressive disorder. These data were analyzed post-hoc to explore the relationship between cognitive measures, depression symptoms (Montgomery-Åsberg Depression Rating Scale, MADRS), and self-reported psychosocial functioning (Sheehan Disability Scale; SDS). Changes from baseline were analyzed in the intent-to-treat population and subgroups with impaired attention, as indicated by baseline Cognitive Drug Research System scores for Power of Attention and Continuity of Attention. Path analyses evaluated the direct and indirect effects of levomilnacipran ER on SDS total score change. Significantly greater improvements were observed for levomilnacipran ER versus placebo for Power of Attention, Continuity of Attention, MADRS, and SDS score changes; the mean differences were larger in the impaired subgroups than in the overall intent-to-treat population. Path analyses showed that the majority of SDS total score improvement (≥50%) was attributable to an indirect treatment effect through MADRS total score change; some direct effect of levomilnacipran ER on SDS total score improvement was also observed. In adults with major depressive disorder, levomilnacipran ER effectively improved measures of depression and cognition, which contributed toward reductions in self-reported functional impairment.

Physical Exercise for Late-Life Depression: Effects on Heart Rate Variability

OBJECTIVES

Late-life major depression is associated with increased cardiovascular risk and impaired autonomic control of the heart, as evident from reduced heart rate variability (HRV). Moreover, antidepressant drug therapy also might be associated with further reductions of HRV. In the SEEDS study, we investigated whether sertraline associated with physical exercise protocols led to improvements of HRV, compared with antidepressant drug therapy alone.

DESIGN

Single-blind randomized controlled trial.

SETTING

Psychiatric consultation-liaison program for primary care.

PARTICIPANTS

Patients aged 65-85 years with major depression, recruited from primary care.

INTERVENTIONS

Sertraline plus structured, tailored group physical exercise (S + EX) versus sertraline alone (S) for 24 weeks.

MEASUREMENTS

HRV indices (RR, percentage of NN intervals greater than 50 msec [pNN50], square root of the mean squared differences of successive NN intervals [RMSSD], standard deviation of heart rate [SDHR], standard deviation of the NN interval [SDNN], high-frequency band [HF], low-frequency band [LF], and their ratio [LF/HF]) were measured at baseline, week 12, and week 24. Psychiatric and medical assessments.

RESULTS

Participants displayed significant improvements of most HRV indices over time, irrespective of the group assignment (pNN50, RMSSD, SDHR, SDNN, HF, LF, and LF/HF). Moreover, patients in the S + EX group displayed greater increases of different HRV indices(RR, pNN50, RMSSD, SDHR, SDNN, HF, and LF) compared with those in the S group.

CONCLUSIONS

The combination of structured physical exercise and sertraline might exert positive effects on the autonomic control of the heart among older patients with major depression.

The interrelationship between attentional and executive deficits in major depressive disorder

OBJECTIVE

Cognitive dysfunction is an established feature of major depressive disorder (MDD). However, it remains unclear whether deficits in different cognitive domains are relatively independent or originate from a circumscribed 'primary deficit'. This study tested the hypothesis that a deficit in attention represents a primary deficit in depression.

METHOD

Neuropsychological function was assessed in 30 depressed patients with MDD and 34 control participants. Cognitive composites were derived from a minimum of three tests and included attention, executive function, visuospatial memory and verbal memory. A multivariate analysis of variance was used to assess group differences in overall cognitive performance, and multiple regression models were used to evaluate the role of attention in deficits in other domains.

RESULTS

The cognitive deficit in the depressed sample was found to be characterized by poorer performance in attention and executive function. When evaluating the interrelationship between the two deficits, the attentional deficit was found to persist when variability in executive function was statistically accounted for, whilst the executive deficit was eliminated when attention was accounted for.

CONCLUSION

The results demonstrated that the attentional deficit could not be explained by deficits in executive function, which provides support for a primary attention deficit in depression.

Depression and postoperative complications: an overview

BACKGROUND

The interaction of depression and anesthesia and surgery may result in significant increases in morbidity and mortality of patients. Major depressive disorder is a frequent complication of surgery, which may lead to further morbidity and mortality.

LITERATURE SEARCH

Several electronic data bases, including PubMed, were searched pairing "depression" with surgery, postoperative complications, postoperative cognitive impairment, cognition disorder, intensive care unit, mild cognitive impairment and Alzheimer's disease.

REVIEW OF THE LITERATURE

The suppression of the immune system in depressive disorders may expose the patients to increased rates of postoperative infections and increased mortality from cancer. Depression is commonly associated with cognitive impairment, which may be exacerbated postoperatively. There is evidence that acute postoperative pain causes depression and depression lowers the threshold for pain. Depression is also a strong predictor and correlate of chronic post-surgical pain. Many studies have identified depression as an independent risk factor for development of postoperative delirium, which may be a cause for a long and incomplete recovery after surgery. Depression is also frequent in intensive care unit patients and is associated with a lower health-related quality of life and increased mortality. Depression and anxiety have been widely reported soon after coronary artery bypass surgery and remain evident one year after surgery. They may increase the likelihood for new coronary artery events, further hospitalizations and increased mortality. Morbidly obese patients who undergo bariatric surgery have an increased risk of depression. Postoperative depression may also be associated with less weight loss at one year and longer. The extent of preoperative depression in patients scheduled for lumbar discectomy is a predictor of functional outcome and patient's dissatisfaction, especially after revision surgery. General postoperative mortality is increased.

CONCLUSIONS

Depression is a frequent cause of morbidity in surgery patients suffering from a wide range of conditions. Depression may be identified through the use of Patient Health Questionnaire-9 or similar instruments. Counseling interventions may be useful in ameliorating depression, but should be subject to clinical trials.

Potential Interactions between the Autonomic Nervous System and Higher Level Functions in Neurological and Neuropsychiatric Conditions

The autonomic nervous system (ANS) maintains the internal homeostasis by continuously interacting with other brain structures. Its failure is commonly observed in many neurological and neuropsychiatric disorders, including neurodegenerative and vascular brain diseases, spinal cord injury, and peripheral neuropathies. Despite the different underlying pathophysiological mechanisms, ANS failure associates with various forms of higher level dysfunctions, and may also negatively impact on patients’ clinical outcome. In this review, we will discuss potential relationships between ANS and higher level dysfunctions in a selection of neurological and neuropsychiatric disorders. In particular, we will focus on the effect of a documented fall in blood pressure fulfilling the criteria for orthostatic hypotension and/or autonomic-reflex impairment on cognitive performances. Some evidence supports the hypothesis that cardiovascular autonomic failure may play a negative prognostic role in most neurological disorders. Despite a clear causal relationship between ANS involvement and higher level dysfunctions that is still controversial, this might have implications for neuro-rehabilitation strategies aimed at improving patients’ clinical outcome.

Vascular burden and cognitive function in late-life depression

OBJECTIVE

To evaluate the relation of vascular risk factors, subclinical, and manifest vascular disease with four domains of cognitive functioning in a large sample of clinically depressed older persons.

METHODS

A cross-sectional analysis was used, and depressed patients were recruited from general practices and mental healthcare institutes. Presence of a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, depressive episode was established with the Composite International Diagnostic Interview. Framingham Risk Score (FRS) was used as a measure for vascular risk profile, ankle-brachial index for subclinical vascular disease, and history of a cardiovascular event as a measure for manifest vascular disease. Three neurocognitive tasks evaluated processing speed, working memory, verbal memory, and interference control.

RESULTS

In 378 participants, linear regression analysis showed that FRS was related to poorer interference control (t = -2.353; df = 377; p <0.05) but to no other cognitive domain after adjustment for age, sex, education level, and depressive symptom severity. Lower ankle-brachial index and history of cardiovascular event were related to slower processing speed (t = 2.659; df = 377; p <0.05 and t = -3.328; df = 377; p <0.01, respectively) but to no other cognitive domain. In 267 participants without manifest vascular disease, higher FRS was related to slower processing speed (t = -2.425; df = 266; p <0.05) and poorer interference control (t = -2.423; df = 266; p <0.05), and lower ankle brachial index was related to slower processing speed (t = 2.171; df = 266; p <0.05).

CONCLUSION

In depressed older persons, vascular burden is related to slower processing speed also in the absence of manifest vascular disease. Poorer interference control was only related to vascular risk factors but not to subclinical or manifest vascular disease.

Heart failure and Alzheimer's disease

It has recently been proposed that heart failure is a risk factor for Alzheimer's disease. Decreased cerebral blood flow and neurohormonal activation due to heart failure may contribute to the dysfunction of the neurovascular unit and cause an energy crisis in neurons. This leads to the impaired clearance of amyloid beta and hyperphosphorylation of tau protein, resulting in the formation of amyloid beta plaques and neurofibrillary tangles. In this article, we will summarize the current understanding of the relationship between heart failure and Alzheimer's disease based on epidemiological studies, brain imaging research, pathological findings and the use of animal models. The importance of atherosclerosis, myocardial infarction, atrial fibrillation, blood pressure and valve disease as well as the effect of relevant medications will be discussed.

Eight-year parallel change in baroreflex sensitivity and memory function in a sample of healthy older adults

OBJECTIVES

To examine whether changes in the cardiac autonomic nervous system (ANS) over time, as expressed by baroreflex sensitivity (BRS), were associated with long-term changes in cognitive performance in elderly individuals without dementia.

DESIGN

Community-based 8-year longitudinal study.

SETTING

Clinical settings.

PARTICIPANTS

Individuals aged 66.9 ± 0.9 (N = 425).

MEASUREMENTS

At baseline and follow-up, subjects underwent a clinical interview, autonomic and vascular measurements, and a neuropsychological evaluation including attentional, executive, and memory tests using standardized Z-scores. BRS was defined as being normal, moderate, or severe alteration at each evaluation. On the basis of the longitudinal changes subjects were stratified as being stable, moderate or improved.

RESULTS

Mean attentional, executive, and memory change Z-scores were -0.41 ± 0.9, -0.15 ± 0.7, and -0.14 ± 0.8, respectively. BRS of 56% of the subjects remained unchanged, of 20% decreased, and of 24% improved. After regression analysis, the worsened BRS group was 1.88 times as likely to have greater memory change as the group with stable BRS (P = .02). No significant association was found between longitudinal change in BRS and attentional and executive changes.

CONCLUSION

In healthy elderly individuals, BRS decrease was associated with a weak but significant decrease in memory function. The long-term effect of BRS on memory changes may suggest a role of the ANS in cognitive decline.

The neurobiological pathogenesis of poststroke depression

Poststroke depression (PSD) is an important consequence after stroke, with negative impact on stroke outcome. The pathogenesis of PSD is complicated, with some special neurobiological mechanism, which mainly involves neuroanatomical, neuron, and biochemical factors and neurogenesis which interact in complex ways. Abundant studies suggested that large lesions in critical areas such as left frontal lobe and basal ganglia or accumulation of silent cerebral lesions might interrupt the pathways of monoamines or relevant pathways of mood control, thus leading to depression. Activation of immune system after stroke produces more cytokines which increase glutamate excitotoxicity, results in more cell deaths of critical areas and enlargement of infarctions, and, together with hypercortisolism induced by stress or inflammation after stroke which could decrease intracellular serotonin transporters, might be the key biochemical change of PSD. The interaction among cytokines, glucocorticoid, and neurotrophin results in the decrease of hippocampal neurogenesis which has been proved to be important for mood control and pharmaceutical effect of selective serotonin reuptake inhibitors and might be another promising pathway to understand the pathogenesis of PSD. In order to reduce the prevalence of PSD and improve the outcome of stroke, more relevant studies are still required to clarify the pathogenesis of PSD.

Mechanism underlying the protective effect of Kaixin Jieyu Fang on vascular depression following cerebral white matter damage

The Chinese compound Kaixin Jieyu Fang can be used to treat vascular depression; however, the underlying mechanism remains unclear. This study established a rat model of chronic cerebral ischemia-caused white matter damage by ligation of the bilateral common carotid arteries. Rats received daily intragastric administration of a suspension of Kaixin Jieyu Fang powder. After 3, 7 and 21 days of treatment, the degree of white matter damage in the cerebral ischemia rat model was alleviated, Bcl-2 protein and mRNA expression in brain tissue increased, and Bax protein and mRNA expression decreased. These results indicate that Kaixin Jieyu Fang can alleviate cerebral white matter damage, and the underlying mechanism is associated with regulation of Bcl-2/Bax protein and mRNA expression, which is one of possible mechanism behind the protective effect of Kaixin Jieyu Fang against vascular depression.

Baroreflex sensitivity, vascular risk factors, and cognitive function in a healthy elderly population: the PROOF cohort

OBJECTIVES

To assess the role of the cardiac autonomic nervous system (ANS), as measured according to spontaneous cardiac baroreflex sensitivity (BRS), in the type and degree of cognitive performance in healthy young-elderly individuals, taking into account the presence of other vascular risk factors.

DESIGN

Community-based cross-sectional study.

SETTING

In-home and clinical settings.

PARTICIPANTS

A subset of participants, aged 66.9±0.9, from a prospective study that aimed to assess the influence of ANS activity on cardiovascular and cerebrovascular morbidity and mortality (N=916).

MEASUREMENTS

All subjects underwent a clinical interview, neuropsychological testing, and autonomic and vascular measurements. Three cognitive domains were defined: attentional (Trail-Making Test Part A, Stroop code and parts I & II), executive (Trail-Making Test Part B, Stroop part III, verbal fluency and similarity tests), and memory (Benton visual retention test, Grober and Buschké procedure). Subjects were stratified according to their scores into normal, low, and impaired performers.

RESULTS

After adjustments to demographic and vascular data, participants with moderate autonomic dysregulation (3<BRS≤6) were determined to be 1.82 times as likely to have memory impairment (odds ratio (OR)=1.82, 95% confidence interval (CI)=1.13-3.17, P=.02) and those with severe autonomic dysregulation (BRS≤3) to be 2.65 as likely (OR=2.65, 95% CI=1.40-5.59, P=.006) as participants with normal BRS (>6).

CONCLUSION

In older individuals without dementia, autonomic dysregulation seems to have a direct, gradual, and independent effect on memory. Future studies are needed to evaluate the long-term effects of BRS and other markers of the ANS on cognitive decline.

Is depression really different in older people?

As politicians and pollsters are well aware, it is easy enough to get different answers to the same question by adjusting the details of the question posed. So I clarify at the outset that I am not considering depression in the broadest sense of any depression occurring in any older person. It seems self-evident that differences are present when defined this way; that is, this includes people with depression in dementia, post-stroke depression, depression in the context of other chronic illnesses and so any assessment of clinical or biological factors would yield differences (in cognition, physical symptoms, and so on) compared to a similar sample of depression in all younger adults. Rather I focus the question on unipolar major depressive disorder (MDD). This is because if there are no differences in late-life MDD compared with younger adults, then it seems unlikely that such differences are present in broader constructs of unipolar disorder (minor depression and dysthymia) and pragmatically because this more tightly defined group has been better assessed. A problem in addressing this question is that relatively few studies have directly compared aspects of depression in older and younger people. Thus, the answer will necessarily be limited and subject to a potential “absence of evidence” error. Here, three key areas of evidence where such comparisons have been made will be examined.

A randomized trial of cognitive rehabilitation in cancer survivors

AIMS

The second most frequently reported post-treatment symptom in cancer survivors are concerns about impaired cognition. Despite numerous studies demonstrating significant impairments in a portion of survivors, information on effective treatments remains an emerging area of research. This study examined the effectiveness of a group-based cognitive rehabilitation intervention in cancer survivors.

MAIN METHODS

This study was a randomized, controlled study of a 7-week cognitive rehabilitation intervention delivered in group format. Participants were evaluated with subjective symptom questionnaires and objective neurocognitive tests prior to and following treatment.

KEY FINDINGS

Twenty-eight participants (mean age 58 years) with a median of 3 years (± 6 years) post-primary/adjuvant treatment and various cancer sites (breast, bladder, prostate, colon, uterine) completed the study. Compared to baseline, the treatment group demonstrated improvements in symptoms of perceived cognitive impairments (p<.01), cognitive abilities (p<.01) and overall quality of life with regard to cognitive symptoms (p<.01) as measured by the FACT-Cog. The treatment group also improved on objective measures of attention (p<.05) and a trend toward improvement on verbal memory. Significant improvement was not observed on all cognitive tests.

SIGNIFICANCE

A group based cognitive rehabilitation intervention in cancer survivors was effective for improving attention abilities and overall quality of life related to cognition. Results suggest that group based cognitive rehabilitation may be an effective intervention for treating cognitive dysfunction in cancer patients and should be further studied in a larger trial with an active control condition.

The vascular depression hypothesis: mechanisms linking vascular disease with depression

The 'Vascular Depression' hypothesis posits that cerebrovascular disease may predispose, precipitate or perpetuate some geriatric depressive syndromes. This hypothesis stimulated much research that has improved our understanding of the complex relationships between late-life depression (LLD), vascular risk factors, and cognition. Succinctly, there are well-established relationships between LLD, vascular risk factors and cerebral hyperintensities, the radiological hallmark of vascular depression. Cognitive dysfunction is common in LLD, particularly executive dysfunction, a finding predictive of poor antidepressant response. Over time, progression of hyperintensities and cognitive deficits predicts a poor course of depression and may reflect underlying worsening of vascular disease. This work laid the foundation for examining the mechanisms by which vascular disease influences brain circuits and influences the development and course of depression. We review data testing the vascular depression hypothesis with a focus on identifying potential underlying vascular mechanisms. We propose a disconnection hypothesis, wherein focal vascular damage and white matter lesion location is a crucial factor, influencing neural connectivity that contributes to clinical symptomatology. We also propose inflammatory and hypoperfusion hypotheses, concepts that link underlying vascular processes with adverse effects on brain function that influence the development of depression. Testing such hypotheses will not only inform the relationship between vascular disease and depression, but also provide guidance on the potential repurposing of pharmacological agents that may improve LLD outcomes.

Organic bases of late-life depression: a critical update

Late-life depression (LLD) is frequently associated with cognitive impairment and increases the risk of subsequent dementia. Cerebrovascular disease, deep white matter lesions, Alzheimer disease (AD) and dementia with Lewy bodies (DLB) have all been hypothesized to contribute to this increased risk, and a host of studies have looked at the interplay between cerebrovascular disease and LLD. This has resulted in new concepts of LLD, such as "vascular depression", but despite multiple magnetic resonance imaging (MRI) studies in this field, the relationship between structural changes in human brain and LLD is still controversial. While pathological findings of suicide in some elderly persons revealed multiple lacunes, small vessel cerebrovascular disease, AD-related lesions or multiple neurodegenerative pathologies, recent autopsy data challenged the role of subcortical lacunes and white matter lesions as major morphological substrates of depressive symptoms as well as poorer executive function and memory. Several neuropathological studies, including a personal clinico-pathological study in a small cohort of elderly persons with LLD and age-matched controls confirmed that lacunes, periventricular and deep white matter demyelination as well as AD-related lesions are usually unrelated to the occurrence of LLD. In the same line, neuropathological data show that early-onset depression is not associated with an acceleration of age-related neurodegenerative changes. Very recent data on the critical role of glia-modulating neuronal dysfunction and degeneration in depression are discussed.