Cheonwangbosimdan mitigates post-traumatic stress disorder-like behaviors through GluN2B-containing NMDA receptor antagonism in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cheonwangbosimdan (CWBSD), a herbal medicine traditionally used for anxiety, insomnia, depression, and heart palpitations, has been reported to have anti-anxiety, antidepressant, cognitive improvement, and neuroprotective effects.

AIM OF THE STUDY

The purpose of this study was to determine if CWBSD could affect post-traumatic stress disorder (PTSD)-like behaviors because it has prioritized clinical use over mechanism study.

MATERIALS AND METHODS

A single prolonged stress (SPS) mouse model, a well-established animal model of PTSD, was used to investigate whether standardized CWBSD could mitigate PTSD-like behaviors through robust behavioral tests, including the elevated plus-maze test and marble burying test for measuring anxiety-like behaviors, the splash test, forced swimming test, and tail suspension test for evaluating depression-like behaviors, and the Y-maze test and novel object recognition test for assessing cognitive function. Additionally, a fear extinction test was employed to determine whether CWBSD might reverse fear memory extinction deficits. Amygdala tissue was isolated from SPS-treated mouse brain and subjected to Western blotting or quantitative PCR to explore mechanisms by which CWBSD could mitigate PTSD-like behaviors.

RESULTS

CWBSD ameliorated emotional impairments and cognitive dysfunction in an SPS-induced PTSD-like mouse model. It also mitigated deficits in abnormal fear memory extinction. Protein expression levels of N-methyl-D-aspartate (NMDA) receptor subunit 2B (GluN2B) and phosphorylation levels of Ca2+/calmodulin-dependent protein kinase II in the amygdala were increased in SPS model mice and normalized by CWBSD. Additionally, co-administration of CWBSD and GluN2B-containing NMDA receptor antagonist, ifenprodil, at each sub-effective dose promoted fear memory extinction.

CONCLUSIONS

CWBSD can alleviate SPS-induced PTSD-like behaviors by normalizing GluN2B-containing NMDA receptor activity in the amygdala. Therefore, CWBSD could be a promising candidate for PTSD treatment with fewer adverse effects and better efficacy than existing therapies.

No Replication of Alzheimer's Disease Genetics as a Moderator of Combat Exposure's Association with PTSD risk in 138,592 Combat Veterans

Large-scale cohort and epidemiological studies suggest that posttraumatic stress disorder (PTSD) confers risk for late-onset Alzheimer's disease (AD) and related dementias (ADRD); however, the basis for this association remains unclear. Several prior studies of military Veterans have reported that carriers of the apolipoprotein E (APOE) ε4 gene variant are at heightened risk for the development of PTSD following combat exposure, suggesting that PTSD and ADRD may share some genetic risk. This cohort study was designed to further examine the hypothesis that ADRD genetic risk also confers risk for PTSD. To do so, we examined APOE ε4 and ε2 genotypes, an AD polygenic risk score (PRS), and other Veteran-relevant risk factors for PTSD in age-stratified groups of individuals of European (n = 123,372) and African (n = 15,220) ancestry in the US Department of Veterans Affairs' Million Veteran Program. Analyses revealed no significant main effect associations between the APOE ε4 (or ε2) genotype or the AD PRS on PTSD severity or diagnosis. There were also no significant interactions between measures of AD genetic risk and either combat exposure severity or history of head injury in association with PTSD in any age group. We conclude that the association between PTSD and the primary ADRD genetic risk factor, APOE ε4, that was reported previously was not replicable in the largest relevant dataset in the world. Thus, the epidemiological association between PTSD and ADRD is not likely to be driven by the major genetic factors underlying ADRD risk.

Traumatic Brain Injury and Post-Traumatic Stress Disorder and Their Influence on Development and Pattern of Alzheimer's Disease Pathology in Later Life

Background

Traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) are potential risk factors for the development of dementia including Alzheimer's disease (AD) in later life. The findings of studies investigating this question are inconsistent though.

Objective

To investigate if these inconsistencies are caused by the existence of subgroups with different vulnerability for AD pathology and if these subgroups are characterized by atypical tau load/atrophy pattern.

Methods

The MRI and PET data of 89 subjects with or without previous TBI and/or PTSD from the DoD ADNI database were used to calculate an age-corrected gray matter tau mismatch metric (ageN-T mismatch-score and matrix) for each subject. This metric provides a measure to what degree regional tau accumulation drives regional gray matter atrophy (matrix) and can be used to calculate a summary score (score) reflecting the severity of AD pathology in an individual.

Results

The ageN-T mismatch summary score was positively correlated with whole brain beta-amyloid load and general cognitive function but not with PTSD or TBI severity. Hierarchical cluster analysis identified five different spatial patterns of tau-gray matter interactions. These clusters reflected the different stages of the typical AD tau progression pattern. None was exclusively associated with PTSD and/or TBI.

Conclusions

These findings suggest that a) although subsets of patients with PTSD and/or TBI develop AD-pathology, a history of TBI or PTSD alone or both is not associated with a significantly higher risk to develop AD pathology in later life. b) remote TBI or PTSD do not modify the typical AD pathology distribution pattern.

A 4-session written emotional disclosure intervention lowers 6-month sympathoadrenal urinary output in persons living with HIV

OBJECTIVE

We previously reported that a brief guided written emotional disclosure (WED) intervention resulted in significant reductions in post-traumatic stress disorder (PTSD) symptomology in women, but not men, living with HIV. Levels of 24-hour urinary output of epinephrine (E) and norepinephrine (NE) are shown to be elevated in persons diagnosed with PTSD. The current study tested whether there was an effect for the 4-week WED intervention on 6-month change in urinary E and NE output amongst persons living with HIV.

METHOD

Fourteen women and 11 men living with HIV randomized to four 30-min expressive writing sessions of either trauma writing or daily events writing in the parent trial were included based upon collection of urine specimens at baseline, 1-, and 6-months after the intervention. Total volume (µg) and concentration (µg/ml) of urinary E and NE were derived from the specimens as study outcomes.

RESULTS

Four repeated measures analyses of covariance (ANCOVA) were performed to evaluate study outcomes using trauma- versus daily-writing as the between-subject factors and collection time point as the within-subject factor, controlling for age and sex. A group x time interaction was observed wherein the trauma writing treatment group showed a significantly greater decrease in total urinary output, F(2, 46) = 4.03, p = .03, and concentration, F(2, 46) = 4.74, p = .01 of epinepherine. Post-hoc analyses revealed the interaction effect for the total, F(2, 22) = 4.82, p = .03, and concentration, F(2, 22) = 7.57, p = .005, of urinary E output over 6-months was significant for women. Interactions were not observed in urinary NE output.

CONCLUSIONS

Significant reductions in the total output and concentration of urinary E were found up to 6-months following initiation of a 4-session guided written emotional disclosure intervention. Profiles of sympathoadrenal activity and response to expressive writing differ between men and women living with HIV. Futher research is need to characterize the putative pathways linking sympathoadrenal response to upstream neurobiological function and downstream inflammatory-immune status in women living with HIV and PTSD.

Association between stress-related disorders and the risk of dementia using the Korean National Sample Cohort: a matched cohort study

Post-traumatic stress disorder (PTSD) is associated with the development of dementia; however, the association of dementia risk with overall stress-related disorders is less known. This study investigated the association between stress-related disorders and the risk of dementia in a Korean nationwide sample cohort. The data analyzed in this study were acquired from the Korean National Health Insurance Service National Sample Cohort between 2002 and 2013. Using a 1:3 propensity score matching, 8906 patients with stress-related disorders and 26,718 control participants were included in the analysis. Patients with stress-related disorders had a higher risk of developing dementia after adjusting for covariates (hazard ratio [HR] = 1.15; 95% confidence interval [CI] 1.01-1.30) than control participants. Patients with PTSD showed the highest risk of increase (HR = 1.78) than those with other types of stress-related disorders. Patients with stress-related disorders showed the highest and significantly increased risk for Alzheimer's dementia (HR = 1.22, 95% CI 1.04-1.56). These results indicated an association between a history of stress-related disorders and the risk of dementia in the South Korean population. Further research investigating the causal mechanisms is needed.

Factors Associated With Distress Related to Posttraumatic Stress Disorder at the End of Life Among U.S. Veterans

CONTEXT

Posttraumatic stress disorder (PTSD) may emerge or re-emerge at end of life (EOL), increasing patient suffering. Understanding factors associated with PTSD at EOL may assist clinicians in identifying high risk veterans.

OBJECTIVES

To determine rates of and variables associated with PTSD-related distress at EOL.

METHODS

Retrospective observational cohort study including veterans who died within a Veterans Affairs (VA) inpatient setting between October 1, 2009 and September 30, 2018 whose next-of-kin completed the Bereaved Family Survey (BFS; N = 42,474). Our primary outcome was PTSD-related distress at EOL, as reported by veteran decedents' next-of-kin on the BFS. Predictors of interest included combat exposure, demographic variables, medical and psychiatric comorbidity, primary serious illness, and palliative care support.

RESULTS

Veteran decedents were majority male (97.7%), non-Hispanic white (77.2%), 65 years or older (80.5%), without combat exposure (80.1%). Almost one in ten (8.9%) veteran decedents experienced PTSD-related distress at EOL. In adjusted analyses, combat exposure, younger age, male sex, and non-white race were associated with PTSD-related distress at EOL. High overall medical comorbidity, dementia, and psychiatric comorbidities including both substance use disorder and depression, were also associated with PTSD-related distress at EOL. Palliative care consultation and emotional support were associated with decreased odds of PTSD-related distress, while pain was associated with increased odds of PTSD-related distress at EOL.

CONCLUSION

Trauma and PTSD screening, pain management, and providing palliative care and emotional support at EOL, particularly in at-risk groups such as veterans from racial/ethnic minority backgrounds and those with dementia, are critical to decreasing PTSD-related distress at EOL.

Adverse events in older adults and the risk of dementia and cognitive decline

Background

Increasing evidence suggests that stress could be a risk factor for dementia but this might vary by gender. This study investigated whether adverse life events were associated with cognitive decline and dementia in later-life, separately in men and women.

Methods

Participants were 12,789 community-dwelling Australians aged ≥ 70 years. Ten common adverse events in later-life were self-reported. Cognitive decline was defined as a 1.5 SD decline from participants' baseline score in tests of global cognition, psychomotor speed, episodic memory, and executive functioning, which were assessed regularly over a maximum of 10.3 years. Dementia was diagnosed according to DSM-IV criteria.

Results

An increased risk of dementia was observed in participants who experienced the death of a spouse/partner (HR: 1.72, 95% CI: 1.17 - 2.52) and for individuals who experienced major financial problems (HR: 1.53, 95% CI: 1.05 - 2.23). The latter also increased the risk of cognitive decline in men specifically (HR: 1.43, 95% CI: 1.10 - 1.86). In contrast, some events for women were associated with a reduced risk of dementia (e.g. close family or friends lost their job/retired (HR: 0.62, 95% CI: 0.40-0.95)).

Limitations

Events including major money problems may result from prodromal dementia symptoms, thus reverse causation needs to be considered.

Conclusions

Adverse life events may influence dementia risk in older adults, but associations vary depending on the nature of the event, and across genders. These findings support the need for early interventions in older people who have experienced adversities, particularly for the death of a loved one.

Is Stress an Overlooked Risk Factor for Dementia? A Systematic Review from a Lifespan Developmental Perspective

Stress exposure and stress reactivity may be potent factors associated with increased risk of dementia. The 2017 Lancet Commission on Dementia and its 2020 update reviewed modifiable risk factors associated with dementia, but stress was not addressed directly. The present study provides a focused review of the association between stress and dementia across the lifespan, with measures of stress including stress exposure, psychological stress, posttraumatic stress disorder (PTSD), and biological markers of stress. Published research articles were identified in the American Psychological Association PsycINFO database (1887-2021), Web of Science database, and Google Scholar. A total of 53 samples from 40 studies published from 1985 to 2020 met inclusion criteria. Results suggest that stressful life events that occur earlier in the lifespan, such as loss of a parent, psychological stress experienced in midlife, and extreme stress responses, i.e., PTSD, correlate with higher risk of dementia. Although results generally are mixed, a consistent theme is that stress experienced earlier in the lifespan and chronic stress portend the greatest risk of dementia. Reducing stress exposure and improving stress management when stress exposure cannot be changed are thus relevant strategies in dementia risk reduction.

Nanowired Delivery of Cerebrolysin Together with Antibodies to Amyloid Beta Peptide, Phosphorylated Tau, and Tumor Necrosis Factor Alpha Induces Superior Neuroprotection in Alzheimer's Disease Brain Pathology Exacerbated by Sleep Deprivation

Sleep deprivation induces amyloid beta peptide and phosphorylated tau deposits in the brain and cerebrospinal fluid together with altered serotonin metabolism. Thus, it is likely that sleep deprivation is one of the predisposing factors in precipitating Alzheimer's disease (AD) brain pathology. Our previous studies indicate significant brain pathology following sleep deprivation or AD. Keeping these views in consideration in this review, nanodelivery of monoclonal antibodies to amyloid beta peptide (AβP), phosphorylated tau (p-tau), and tumor necrosis factor alpha (TNF-α) in sleep deprivation-induced AD is discussed based on our own investigations. Our results suggest that nanowired delivery of monoclonal antibodies to AβP with p-tau and TNF-α induces superior neuroprotection in AD caused by sleep deprivation, not reported earlier.

Antidepressant’s long-term effect on cognitive performance and cardiovascular system

Background: The nature of antidepressants and their adverse effects should be considered when treating severe depression in individuals with psychotic symptoms. Antidepressant prescription rates have risen steadily over the last 30 years, affecting people of all ages. Aim: The goal of this study was to see if depression and antidepressant usage were linked to long-term changes in cognitive function and cardiovascular health. Methodology: Meta-analysis was performed using PRISMA guidelines along with using the SPIDER search framework using related keywords on different search engines i.e. Google scholars, PubMed, Scopus, ISI, etc. Total (n=2256) papers were obtained and assessed for eligibility. Altogether 15 studies were included using databases and other methods. The Newcastle-Ottawa Scale examined the grades provided by the data after numerous screenings. Result: A distinct link was found between antidepressants with cognitive performance and the cardiovascular system. Dementia and hypertension were prevailing long-term effects caused by frequent use of antidepressants in chronic and mild depression.

Association of Posttraumatic Stress Disorder With Accelerated Cognitive Decline in Middle-aged Women

IMPORTANCE

Posttraumatic stress disorder (PTSD) has been hypothesized to lead to impaired cognitive function. However, no large-scale studies have assessed whether PTSD is prospectively associated with cognitive decline in middle-aged adults.

OBJECTIVE

To assess the association between PTSD and decline in cognitive function over time.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included participants from the Nurses' Health Study II, an ongoing longitudinal cohort study involving community-dwelling middle-aged female nurses residing in the US who had at least a 2-year nursing degree at the time of enrollment in 1989. The present study included 12 270 trauma-exposed women who were enrolled in the PTSD substudy of the Nurses' Health Study II and completed 1 to 5 cognitive assessments. Data were collected from March 1, 2008, to July 30, 2019.

EXPOSURES

Lifetime PTSD symptoms, assessed using a validated questionnaire between March 1, 2008, and February 28, 2010.

MAIN OUTCOMES AND MEASURES

The main outcome was evaluated using the Cogstate Brief Battery, a self-administered online cognitive battery. Cognitive function was measured by a psychomotor speed and attention composite score and a learning and working memory composite score. Women completed the Cogstate Brief Battery every 6 or 12 months (up to 24 months) from October 3, 2014, to July 30, 2019. Linear mixed-effects models were used to evaluate the association of PTSD symptoms with the rate of change in cognition over follow-up, considering a broad range of relevant covariates, including the presence of depression symptoms and history of clinician-diagnosed depression. The rate of cognitive change was adjusted for potential practice effects (ie, potential changes in test results that occur when a test is taken more than once) by including indicators for the number of previous tests taken.

RESULTS

Among 12 270 women, the mean (SD) age at the baseline cognitive assessment was 61.1 (4.6) years; 125 women (1.0%) were Asian, 75 (0.6%) were Black, 156 (1.3%) were Hispanic, 11 767 (95.9%) were non-Hispanic White, and 147 (1.2%) were of other race and/or ethnicity. A higher number of PTSD symptoms was associated with worse cognitive trajectories. Compared with women with no PTSD symptoms, women with the highest symptom level (6-7 symptoms) had a significantly worse rate of change in both learning and working memory (β = -0.08 SD/y; 95% CI, -0.11 to -0.04 SD/y; P < .001) and psychomotor speed and attention (β = -0.05 SD/y; 95% CI, -0.09 to -0.01 SD/y; P = .02), adjusted for demographic characteristics. Associations were unchanged when additionally adjusted for behavioral factors (eg, 6-7 symptoms in the analysis of learning and working memory: β = -0.08 SD/y; 95% CI, -0.11 to -0.04 SD/y; P < .001) and health conditions (eg, 6-7 symptoms in the analysis of learning and working memory: β = -0.08 SD/y; 95% CI, -0.11 to -0.04 SD/y; P < .001) and were partially attenuated but still evident when further adjusted for practice effects (eg, 6-7 symptoms in the analysis of learning and working memory: β = -0.07 SD/y; 95% CI, -0.10 to -0.03 SD/y; P < .001) and comorbid depression (eg, 6-7 symptoms in the analysis of learning and working memory: β = -0.07 SD/y; 95% CI, -0.11 to -0.03 SD/y; P < .001).

CONCLUSIONS AND RELEVANCE

In this large-scale prospective cohort study, PTSD was associated with accelerated cognitive decline in middle-aged women, suggesting that earlier cognitive screening among women with PTSD may be warranted. Given that cognitive decline is strongly associated with subsequent Alzheimer disease and related dementias, better understanding of this association may be important to promote healthy aging.

An Integrative Review of Behavioral Disturbances in Veterans With Dementia and PTSD

OBJECTIVE

Both posttraumatic stress disorder (PTSD) and dementia have been associated with a variety of behavioral changes; however, little is known about the behavioral consequences of comorbid PTSD and dementia. An integrative review was conducted to identify and examine studies reporting on behavioral disturbances in Veterans with PTSD and dementia.

METHODS

PubMed and PsychINFO databases were searched for articles on behavioral disturbances in Veterans with comorbid PTSD and dementia.

RESULTS

Seven studies met inclusion for this review, sampling a total of 822 Veterans. Preliminary findings suggest that though Veterans with dementia and comorbid PTSD may present with more difficult behavioral symptoms, they do not typically display increased levels of aggression.

CONCLUSION

Given the limited study inventory, the key finding from this review highlights the lack of methodologically rigorous empirical studies on this topic. A research agenda is proposed to encourage future studies to address gaps in the literature.

Risk of Dementia in Posttraumatic Stress Disorder

Several studies have investigated the risk of dementia in posttraumatic stress disorder (PTSD) using a varying methodology. Epidemiological studies have found an increased risk of dementia with PTSD in Vietnam veterans as well as the general population. Laboratory studies reported the accelerated formation of β-amyloid and tau, which represent the primary pathology of Alzheimer's dementia in animal models of PTSD. These investigations were conducted against a background of cognitive impairment and atrophy of the hippocampus and certain cortical areas in patients with PTSD. Very few studies have investigated the pathological basis in humans for the reported association of PTSD with dementia. This important gap in the literature has recently been partly addressed by very few studies that estimated the burden of β-amyloid and tau. The PET studies did not show an association between PTSD and the specific pathology of Alzheimer's disease or signs of neurodegenerative diseases underlying other dementia syndromes. Another study demonstrated decreased plasma β-amyloid load and increased plasma β-amyloid 42/40 ratio in PTSD without PET evaluation. While PTSD is associated with an increased risk of dementia syndrome in general, there is no convincing evidence that it causes or accelerates the pathology of Alzheimer's disease, which causes the most common type of dementia. Factors that may account for the association between PTSD and a clinical diagnosis of dementia are discussed in this review.

It gets better: childhood sexual abuse and trauma symptoms in female older adults

While there has been great deal of research conducted on the effects of child sexual abuse (CSA) on trauma symptoms in children and adults, there is less knowledge on the effects on trauma symptoms in female older adult CSA survivors. The aim of this study was to investigate current symptoms of trauma in adult female survivors of child sexual abuse across each successive decade, beginning with eighteen year olds. This retrospective, anonymous online study gathered a sample of 223 adult female survivors of CSA (38 of whom were aged 50-59 (17%), and 20 of whom were 60+ years of age (9%)), and surveyed their trauma history and their current symptomology. In our sample, the survivors with the most severe trauma symptoms were between 18 and 29 years old. Each subsequent decade reported fewer trauma symptoms, with respondents in the 60+ age group reporting the lowest trauma symptom severity. While a cross-sectional study does not allow us to evaluate individuals' experiences over time, these results suggest that the negative impacts of CSA may abate over the life course. Future research should consider these questions longitudinally to explore whether these results are related to survivorship (those with worse outcomes dying younger) and whether these effects endure as female older adults experience physical and mental challenges in later life.

Dementia in military and veteran populations: a review of risk factors-traumatic brain injury, post-traumatic stress disorder, deployment, and sleep

The military population face a unique set of risk factors that may increase the risk of being diagnosed with dementia. Traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) have a higher prevalence in this group in comparison to the civilian population. By delving into the individual relationships between TBI and dementia, and PTSD and dementia, we are able to better explore dementia in the military and veteran populations. While there are some inconsistencies in results, the TBI-dementia association has become more widely accepted. Moderate-to-severe TBI has been found to increase the risk of being diagnosed with Alzheimer's disease. A correlation between PTSD and dementia has been established, however, whether or not it is a causal relationship remains unclear. Factors such as blast, combat and chemical exposure may occur during a deployment, along with TBI and/or PTSD diagnosis, and can impact the risk of dementia. However, there is a lack of literature exploring the direct effects of deployment on dementia risk. Sleep problems have been observed to occur in those following TBI, PTSD and deployment. Poor sleep has been associated with possible dementia risk. Although limited studies have focused on the link between sleep and dementia in military and veteran populations, sleep is a valuable factor to study due to its association and interconnection with other military/veteran factors. This review aims to inform of various risk factors to the cognitive health of military members and veterans: TBI, PTSD, deployment, and sleep.

Altered basal forebrain BOLD signal variability at rest in posttraumatic stress disorder: A potential candidate vulnerability mechanism for neurodegeneration in PTSD

Individuals with posttraumatic stress disorder (PTSD) are at increased risk for the development of various forms of dementia. Nevertheless, the neuropathological link between PTSD and neurodegeneration remains unclear. Degeneration of the human basal forebrain constitutes a pathological hallmark of neurodegenerative diseases, such as Alzheimer's and Parkinson's disease. In this seed-based resting-state (rs-)fMRI study identifying as outcome measure the temporal BOLD signal fluctuation magnitude, a seed-to-voxel analyses assessed temporal correlations between the average BOLD signal within a bilateral whole basal forebrain region-of-interest and each whole-brain voxel among individuals with PTSD (n = 65), its dissociative subtype (PTSD+DS) (n = 38) and healthy controls (n = 46). We found that compared both with the PTSD and healthy controls groups, the PTSD+DS group exhibited increased BOLD signal variability within two nuclei of the seed region, specifically in its extended amygdaloid region: the nucleus accumbens and the sublenticular extended amygdala. This finding is provocative, because it mimics staging models of neurodegenerative diseases reporting allocation of neuropathology in early disease stages circumscribed to the basal forebrain. Here, underlying candidate etiopathogenetic mechanisms are neurovascular uncoupling, decreased connectivity in local- and large-scale neural networks, or disrupted mesolimbic dopaminergic circuitry, acting indirectly upon the basal forebrain cholinergic pathways. These abnormalities may underpin reward-related deficits representing a putative link between persistent traumatic memory in PTSD and anterograde memory deficits in neurodegeneration. Observed alterations of the basal forebrain in the dissociative subtype of PTSD point towards the urgent need for further exploration of this region as a potential candidate vulnerability mechanism for neurodegeneration in PTSD.

Posttraumatic Stress Disorder in the Elderly

Posttraumatic stress disorder (PTSD) can occur at any point in the life span and can last for decades. Chronic PTSD can affect quality of life and have a negative impact on physical function and health in the elderly and may be associated with premature aging and dementia. It is critical that clinicians screen for trauma-based symptoms and to treat as appropriate.

Stress diagnoses in midlife and risk of dementia: a register-based follow-up study

OBJECTIVES

Previous studies indicated that stress diagnoses increase the risk of dementia. However, previous results may be biased by confounding, reverse causation and misclassification. Therefore, the main aim of this study was to investigate the association between clinically diagnosed stress in midlife and later dementia risk, while addressing limitations of previous studies.

METHODS

The study population was selected from all individuals in Denmark born 1935-1956. Individuals diagnosed with stress in midlife (aged 37-58 years) were matched (1:5) with individuals without stress diagnoses based on sex and birthdate (N = 103,484). Data were retrieved from national registers. Cox regression models were adjusted for socio-demographic factors and different morbidities.

RESULTS

We found a 2.20 (95% CI: 1.93-2.50) times higher rate of dementia among individuals with any stress diagnosis registered in midlife compared with no stress diagnosis. Hazard rate ratios of dementia were 1.73 (95% CI: 1.13-2.65) among individuals with acute stress reactions, 2.37 (95% CI: 2.05-2.74) among individuals with adjustment disorders, and 2.20 (95% CI: 1.73-2.80) among individuals with unspecified stress reactions. Individuals with PTSD and other stress reactions had non-significantly elevated rates of dementia. Adjustment for confounding only slightly attenuated the association, and reverse causation did not appear to bias the results substantially.

CONCLUSION

Our results support the hypothesis that severe stress in midlife is an important risk factor for dementia. This finding emphasizes the importance of identifying and treating severe stress in midlife to reduce potential detrimental consequences for brain health in later life.

Comorbidity rates of Posttraumatic Stress Disorder in dementia: a systematic literature review

Background: Post Traumatic Stress Disorder (PTSD) has been described as an independent risk factor for cognitive decline and dementia. At the same time, cognitive deterioration and increased loss experiences in dementia may increase liability for the reactivation of traumatic memories and thereby PTSD symptoms. Objective: In order to investigate co-occurrence of PTSD in dementia this systematic literature review summarizes all the available evidence on reported comorbidity rates of PTSD in patients with dementia. Method: PubMed, Embase, PsycINFO and CINAHL were searched for potential publications investigating the co-occurrence of PTSD in dementia until 25 November 2019. Cohort and cross-sectional studies were included. To assure current comorbidity of PTSD in dementia, only publications with a recent PTSD diagnosis (<2 years before onset of dementia) were selected. Results: Of the 860 identified abstracts, three studies (0.35%) met the eligibility criteria and were included. These three studies concerned only military veteran populations, and they comprised two cross-sectional cohort studies and one prospective cohort study. The estimated comorbidity rate of PTSD in veterans with dementia varied between 4.7% and 7.8%. Conclusions: The limited research available shows comorbidity rates only in military veterans, which were possibly dependent on investigated population with respect to dementia severity and possibly associated behavioural and psychiatric symptoms of dementia (BPSD). In dementia patients the comorbidity with PTSD may be high and we suggest that worldwide the impact of PTSD in dementia is high and probably underestimated. Research and care on this topic should improve urgently with the current expanding prevalence of dementia. A first step to improve quality of dementia research and care would be to develop a structured tool to diagnose PTSD in these patients.

Monoclonal Antibodies Application in Lateral Flow Immunochromatographic Assays for Drugs of Abuse Detection

Lateral flow assays (lateral flow immunoassays and nucleic acid lateral flow assays) have experienced a great boom in a wide variety of early diagnostic and screening applications. As opposed to conventional examinations (High Performance Liquid Chromatography, Polymerase Chain Reaction, Gas chromatography-Mass Spectrometry, etc.), they obtain the results of a sample's analysis within a short period. In resource-limited areas, these tests must be simple, reliable, and inexpensive. In this review, we outline the production process of antibodies against drugs of abuse (such as heroin, amphetamine, benzodiazepines, cannabis, etc.), used in lateral flow immunoassays as revelation or detection molecules, with a focus on the components, the principles, the formats, and the mechanisms of reaction of these assays. Further, we report the monoclonal antibody advantages over the polyclonal ones used against drugs of abuse. The perspective on aptamer use for lateral flow assay development was also discussed as a possible alternative to antibodies in view of improving the limit of detection, sensitivity, and specificity of lateral flow assays.

Association of Stress-Related Disorders With Subsequent Neurodegenerative Diseases

Importance

Posttraumatic stress disorder (PTSD) has been associated with increased risk for dementia. Less is known, however, about other stress-related disorders and their associations with neurodegenerative diseases.

Objective

To examine the association between stress-related disorders and risk for neurodegenerative diseases.

Design, Setting, and Participants

This population-matched and sibling cohort study was conducted in Sweden using data from nationwide health registers, including the Swedish National Patient Register. Individuals who received their first diagnosis of stress-related disorders between January 1, 1987, and December 31, 2008, were identified. Individuals who had a history of neurodegenerative diseases, had conflicting or missing information, had no data on family links, or were aged 40 years or younger at the end of the study were excluded. Individuals with stress-related disorders were compared with the general population in a matched cohort design; they were also compared with their siblings in a sibling cohort. Follow-up commenced from the age of 40 years or 5 years after the diagnosis of stress-related disorders, whichever came later, until the first diagnosis of a neurodegenerative disease, death, emigration, or the end of follow-up (December 31, 2013), whichever occurred first. Data analyses were performed from November 2018 to April 2019.

Exposures

Diagnosis of stress-related disorders (PTSD, acute stress reaction, adjustment disorder, and other stress reactions).

Main Outcomes and Measurements

Neurodegenerative diseases were identified through the National Patient Register and classified as primary or vascular. Alzheimer disease, Parkinson disease, and amyotrophic lateral sclerosis were evaluated separately. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) with 95% CIs after controlling for multiple confounders.

Results

The population-matched cohort included 61 748 exposed individuals and 595 335 matched unexposed individuals. A total of 44 839 exposed individuals and their 78 482 unaffected full siblings were included in the sibling cohort analysis. The median (interquartile range) age at the start of follow-up was 47 (41-56) years, and 24 323 (39.4%) of the exposed individuals were male. The median (interquartile range) follow-up was 4.7 (2.1-9.8) years. Compared with unexposed individuals, individuals with a stress-related disorder were at an increased risk of neurodegenerative diseases (HR, 1.57; 95% CI, 1.43-1.73). The risk increase was greater for vascular neurodegenerative diseases (HR, 1.80; 95% CI, 1.40-2.31) than for primary neurodegenerative diseases (HR, 1.31; 95% CI, 1.15-1.48). A statistically significant association was found for Alzheimer disease (HR, 1.36; 95% CI, 1.12-1.67) but not Parkinson disease (HR, 1.20; 95% CI, 0.98-1.47) or amyotrophic lateral sclerosis (HR, 1.20; 95% CI, 0.74-1.96). Results from the sibling cohort corroborated results from the population-matched cohort.

Conclusions and Relevance

This study showed an association between stress-related disorders and an increased risk of neurodegenerative diseases. The relative strength of this association for vascular neurodegenerative diseases suggests a potential cerebrovascular pathway.

Atypical Antipsychotics Augmentation in Patients with Depressive Disorder and Risk of Subsequent Dementia: A Nationwide Population-Based Cohort Study

BACKGROUND

While atypical antipsychotic medications are widely used for treating depressive disorders, their long-term effects on the risk of subsequent dementia have not been studied adequately.

OBJECTIVE

To investigate whether the risk of dementia differs according to the use of atypical antipsychotic drugs, and compare the effects of antipsychotic agents on dementia risk in individuals with late-life depressive disorders.

METHODS

A nationwide population-based retrospective cohort study was conducted using data from the National Health Insurance Service-Senior Cohort of South Korea. Atypical antipsychotic dosages were standardized using a defined daily dose, and the cumulative dosage was calculated. Participants were observed from January 2008 to December 2015. Cox proportional hazard regression analysis was used to estimate the hazard ratios.

RESULTS

The cohort included 43,788 elderly adults with depressive disorders: 9,901 participants (22.6%) were diagnosed with dementia. Findings showed that atypical antipsychotics were prescribed to 1,967 participants (4.5%). Compared with non-users, users of atypical antipsychotics experienced a significantly higher risk for dementia with an adjusted hazard ratio (aHR) of 1.541 (95% confidence interval [CI], 1.415-1.678). A cumulative dose-response relationship was observed (test for trend, p < 0.0001). Among atypical antipsychotics, risperidone displayed the highest risk for dementia (aHR 1.767, [95% CI, 1.555-2.009]).

CONCLUSION

In this study of elderly individuals with depressive disorders, atypical antipsychotic use was associated with a significantly higher risk of subsequent dementia. Healthcare professionals should be aware of this potential long-term risk. A limitation that should be mentioned is that we could not exclude patients with bipolar depression.

Holocaust exposure and late-life cognitive performance in men with coronary heart disease

BACKGROUND

Holocaust victims experienced extreme physical and mental stress that could lead to prolonged deficits in psychological and physiological well-being. We aimed to examine whether exposure to Holocaust conditions is associated with cognitive function and decline in a sample of old male adults with coronary heart disease (CHD).

METHODS

The sample included 346 individuals with CHD who participated in a clinical trial in 1990-1997 (mean age 56.7 ± 6.5 y). During 2004-2008 (mean age 71.8 ± 6.5 y) and 2011-2013 (mean age 77.1 ± 6.4 y) participants underwent computerized cognitive assessments. Exposure to Holocaust conditions was based on self-report at the second assessment. Linear regression and mixed-effect models were conducted to evaluate the associations between Holocaust survivorship and subsequent cognitive performance and rate of cognitive decline.

RESULTS

Forty-Three participants (12%) survived concentration camps/ghettos, 69 (20%) were Holocaust survivors who escaped concentration camps/ghettos, and 234 (68%) were not Holocaust survivors. After adjustment for potential confounders, concentration camp/ghetto survivors had poorer global cognitive performance and poorer attention (β = -3.90; 95%CI: 7.11;-0.68 and β = -4.11; 95%CI: 7.83;-0.38, respectively) compared to individuals who were not exposed to Holocaust conditions. Additionally, participants who reported being at concentration camps/ghettoes had increased cognitive decline in global performance and executive function (β = -0.19; 95%CI: 0.37;-0.008 and β = -0.29; 95%CI: 0.53;-0.06, respectively) compared to participants who were not Holocaust survivors. Lastly, those who were Holocaust survivors but not in concentration camps/ghettos had greater decline in attention (β = -0.11; 95%CI: 0.21;-0.01).

DISCUSSION

Exposure to Holocaust conditions in early-life may be linked with poorer cognitive function and greater cognitive decline decades later in old-adults with CHD.

Potential Impacts of Extreme Heat and Bushfires on Dementia

Australia often experiences natural disasters and extreme weather conditions such as: flooding, sandstorms, heatwaves, and bushfires (also known as wildfires or forest fires). The proportion of the Australian population aged 65 years and over is increasing, alongside the severity and frequency of extreme weather conditions and natural disasters. Extreme heat can affect the entire population but particularly at the extremes of life, and patients with morbidities. Frequently identified as a vulnerable demographic in natural disasters, there is limited research on older adults and their capacity to deal with extreme heat and bushfires. There is a considerable amount of literature that suggests a significant association between mental disorders such as dementia, and increased vulnerability to extreme heat. The prevalence rate for dementia is estimated at 30%by age 85 years, but there has been limited research on the effects extreme heat and bushfires have on individuals living with dementia. This review explores the differential diagnosis of dementia, the Australian climate, and the potential impact Australia's extreme heat and bushfires have on individuals from vulnerable communities including low socioeconomic status Indigenous and Non-Indigenous populations living with dementia, in both metropolitan and rural communities. Furthermore, we investigate possible prevention strategies and provide suggestions for future research on the topic of Australian bushfires and heatwaves and their impact on people living with dementia. This paper includes recommendations to ensure rural communities have access to appropriate support services, medical treatment, awareness, and information surrounding dementia.

Demographic, Health, and Exposure Risks Associated With Cognitive Loss, Alzheimer's Disease and Other Dementias in US Military Veterans

The US military veteran population receiving care through the Veterans Health Administration (VHA) is particularly susceptible to cognitive impairment and dementias such as Alzheimer's disease and related dementias due to demographic, clinical, and economic factors. In this report we summarize the prevalence of dementia among US veterans and risks associated with AD and related dementias. We discuss the likelihood that these risks may be increasing in those about to enter the age in which dementias are common. We propose that VHA, the largest integrated health care system in the US, has shown promise in managing health risks that impact dementia prevention and propose further system wide approaches to be assessed for effective dementia prevention and care delivery.

The long-term consequences of trauma and posttraumatic stress disorder symptoms on later life cognitive function and dementia risk

Stress may be a risk factor for dementia, however it is unknown whether post-traumatic stress disorder (PTSD) symptoms are associated with incident dementia in community-dwelling older individuals. The aim was to determine whether lifetime major trauma with and without re-experiencing of PTSD symptoms is associated with later-life cognition and dementia risk. Participants were 1,700 community-dwelling older adults (65+) in the longitudinal ESPRIT study followed over 14 years. Lifetime major traumatic exposure and PTSD were assessed using Watson's PTSD Inventory. Cognitive tests assessed global cognition, visual memory, verbal fluency, psychomotor speed and executive function. Incident dementia was diagnosed according to DSM-IV criteria. Lifetime major trauma (versus no trauma) was associated with significantly increased executive function and increased global function in men, however women with lifetime trauma and re-experiencing symptoms had a significantly increased risk of low global cognition. Over 14 years, lifetime trauma without re-experiencing symptoms was associated with a significantly decreased risk of incident dementia, particularly for women. Lifetime major trauma without re-experiencing symptoms (but not with) may be protective for later life cognitive function. However, the mechanisms and moderating factors underlying these association requires further investigation.

The Potential Contribution of Chronic Pain and Common Chronic Pain Conditions to Subsequent Cognitive Decline, New Onset Cognitive Impairment, and Incident Dementia: A Systematic Review and Conceptual Model for Future Research

BACKGROUND

Growing evidence suggests that chronic pain and certain chronic pain conditions may increase risk for cognitive decline and dementia.

OBJECTIVE

In this systematic review, we critically evaluate available evidence regarding the association of chronic pain and specific common chronic pain conditions to subsequent decline in cognitive function, new onset cognitive impairment (CI), and incident Alzheimer's disease and related dementias (ADRD); outline major gaps in the literature; and provide a preliminary conceptual model illustrating potential pathways linking pain to cognitive change.

METHODS

To identify qualifying studies, we searched seven scientific databases and scanned bibliographies of identified articles and relevant review papers. Sixteen studies met our inclusion criteria (2 matched case-control, 10 retrospective cohort, 2 prospective cohort), including 11 regarding the association of osteoarthritis (N = 4), fibromyalgia (N = 1), or headache/migraine (N = 6) to incident ADRD (N = 10) and/or its subtypes (N = 6), and 5 investigating the relation of chronic pain symptoms to subsequent cognitive decline (N = 2), CI (N = 1), and/or ADRD (N = 3).

RESULTS

Studies yielded consistent evidence for a positive association of osteoarthritis and migraines/headaches to incident ADRD; however, findings regarding dementia subtypes were mixed. Emerging evidence also suggests chronic pain symptoms may accelerate cognitive decline and increase risk for memory impairment and ADRD, although findings and measures varied considerably across studies.

CONCLUSION

While existing studies support a link between chronic pain and ADRD risk, conclusions are limited by substantial study heterogeneity, limited investigation of certain pain conditions, and methodological and other concerns characterizing most investigations to date. Additional rigorous, long-term prospective studies are needed to elucidate the effects of chronic pain and specific chronic pain conditions on cognitive decline and conversion to ADRD, and to clarify the influence of potential confounding and mediating factors.

Post-traumatic stress disorder as a risk factor for dementia: systematic review and meta-analysis

BACKGROUND

Post-traumatic stress disorder (PTSD) has been identified as a potential risk factor for developing dementia. There are currently, however, no meta-analyses quantifying this risk.

AIMS

To systematically review and quantify the risk of future dementia associated with PTSD across populations. PROSPERO registration number CRD42019130392.

METHOD

We searched nine electronic databases up to 25 October 2019 for longitudinal studies assessing PTSD and risk of dementia. We used random- and fixed-effects meta-analyses to pool estimates across studies.

RESULTS

PTSD was associated with a significant risk for all-cause dementia: pooled hazard ratio HR = 1.61 (95% CI 1.43-1.81, I2= 85.8%, P < 0.001; n = 1 693 678; 8 studies). Pooled HR was 1.61 (95% CI 1.46-1.78; I2= 80.9%, P < 0.001; n = 905 896; 5 studies) in veterans, and 2.11 (95% CI 1.03-4.33, I2= 91.2%, P < 0.001; n = 787 782; 3 studies) in the general population. The association between PTSD and dementia remained significant after excluding studies with high risk of bias (HR = 1.55, 95% CI 1.39-1.73, I2= 83.9%, P < 0.001; n = 1 684 928; 7 studies). Most studies included were retrospective and there was evidence of high heterogeneity.

CONCLUSIONS

This is the first meta-analysis quantifying the association of PTSD and risk of dementia showing that PTSD is a strong and potentially modifiable risk factor for all-cause dementia. Future studies investigating potential causal mechanisms, and the protective value of treating PTSD are needed.

Risk of Dementia in persons who have previously experienced clinically-significant Depression, Anxiety, or PTSD: A Systematic Review and Meta-Analysis

BACKGROUND

Depression, anxiety and PTSD appear to be linked to dementia, but it is unclear whether they are risk factors (causal or prodromal) for, comorbid with, or sequelae to (secondary effect of) dementia. Existing meta-analyses have examined depression or anxiety in all-cause dementia, Alzheimer's disease (AD) and vascular dementia (VaD), but have not considered post-traumatic stress disorder (PTSD), dementia with Lewy bodies (DLB), or frontotemporal dementia (FTD). The current meta-analysis examined the risk of developing dementia (AD, VaD, DLB, FTD, all-cause) in people with and without a history of clinically-significant depression, anxiety or PTSD in order to better understand the link between mental illness and dementia (PROSPERO number: CRD42018099872).

METHODS

PubMed, EMBASE, PsycINFO and CINAHL searches identified 36 eligible studies.

RESULTS

There is a higher risk of developing all-cause dementia and AD in people with previous depression, and a higher risk of all-cause dementia in people with prior anxiety, than in persons without this history. Prior PTSD was not associated with a higher risk of later being diagnosed with dementia.

LIMITATIONS

The data for anxiety, PTSD, DLB and FTD were limited.

CONCLUSIONS

Depression and anxiety appear to be risk factors for dementia, but longitudinal studies across adulthood (young adult/mid-life/older adult) are needed to evaluate the likely causal or prodromal nature of this risk. The link between PTSD and dementia remains unclear. Regular screening for new onset mental illness and for cognitive changes in older adults with a history of mental illness may assist with earlier identification of dementia.

The Interplay Between Post-traumatic Stress Disorder and Dementia: A Systematic Review

BACKGROUND

Post-traumatic stress disorder (PTSD) has been reported to increase the risk for dementia in veterans and civilians. Conversely, case reports have described the delayed onset of PTSD in individuals developing dementia, suggesting a complex relationship between these two conditions.

OBJECTIVES

To critically review studies investigating the association between PTSD and dementia and to assess the evidence for a bidirectional relationship between the two conditions.

METHODS

A systematic review of Web of Science Core databases was carried out from inception of databases up to November 2018 to identify observational studies pertaining to both PTSD and dementia. Populations enrolled, stressors and neuropathologies, and main outcomes of studies were extracted, in addition to age at trauma and at onset of PTSD and dementia. The different temporal relationships between trauma and onset of the conditions were characterized.

RESULTS

Twenty-five articles were included in the review; 14 articles assessed the association of PTSD with subsequent dementia and 11 articles reported the delayed onset of PTSD with the onset of dementia. Most reported traumas occurred in early-life (<40 years) and were related to war combat experiences. PTSD in mid-life (between 40 and 60 years of age) was associated with an increased risk of late-onset dementia. Numerous case series reported the delayed onset of PTSD in Alzheimer's disease and vascular dementia.

CONCLUSION

Current evidence suggests that PTSD and dementia have a bidirectional relationship: PTSD increases the risk for late-onset dementia and dementia increases the risk for delayed-onset PTSD in those who experienced a significant trauma earlier in life.

Validity of early-onset dementia diagnoses in VA electronic medical record administrative data

OBJECTIVE

To determine the validity of diagnoses indicative of early-onset dementia (EOD) obtained from an algorithm using administrative data, we examined Veterans Health Administration (VHA) electronic medical records (EMRs).

METHOD

A previously used method of identifying cases of dementia using administrative data was applied to a random sample of 176 cases of Post-9/11 deployed veterans under 65 years of age. Retrospective, cross-sectional examination of EMRs was conducted, using a combination of administrative data, chart abstraction, and review/consensus by board-certified neuropsychologists.

RESULTS

Approximately 73% of EOD diagnoses identified using existing algorithms were identified as false positives in the overall sample. This increased to approximately 76% among those with mental health conditions and approximately 85% among those with mild traumatic brain injury (TBI; i.e. concussion). Factors related to improved diagnostic accuracy included more severe TBI, diagnosing clinician type, presence of neuroimaging data, absence of a comorbid mental health condition diagnosis, and older age at time of diagnosis.

CONCLUSIONS

A previously used algorithm for detecting dementia using VHA administrative data was not supported for use in the younger adult samples and resulted in an unacceptably high number of false positives. Based on these findings, there is concern for possible misclassification in population studies using similar algorithms to identify rates of EOD among veterans. Further, we provide suggestions to develop an enhanced algorithm for more accurate dementia surveillance among younger populations.

Post-traumatic stress disorder and dementia in veterans: A scoping literature review

Emerging research has found an association between post-traumatic stress disorder (PTSD) and dementia in veterans, yet little is known about the nature of this association and how it is conceptualized in the literature. The purpose of this scoping review is to understand how the relationship between PTSD and dementia in veterans is recognized and described in the peer-reviewed literature. A scoping review was conducted using Arksey and O'Malley's (International Journal of Social Research Methodology, 8, 19, 2005) framework. Articles are included if participants were veterans with a focus on PTSD and dementia. A total of six databases (CINAHL, MEDLINE, EMBASE, PsycINFO, HealthSTAR, and PubMed) were searched along with the reference lists of eligible sources in September 2018. Thematic analysis was used to summarize the data. Thirty-six studies were included in this review. Three main themes emerged from the literature: (i) symptomatic expression of PTSD and dementia; (ii) aetiology underlying the relationship between PTSD and dementia; and (iii) implications of PTSD and dementia on healthcare providers, treatment, and resources. This study highlights the ongoing need to understand mechanisms underlying the association between PTSD and dementia, the need for definition of PTSD symptoms, and to sensitize healthcare providers to the presence of PTSD when caring for veterans with dementia.

GSK-3β and ERK1/2 incongruously act in tau hyperphosphorylation in SPS-induced PTSD rats

Post-traumatic stress disorder (PTSD) manifests in neurocognitive deficits in association with increased tau deposition, which mainly consist of phosphorylated tau in Alzheimer disease (AD) brain. However, the exact mechanism of PTSD inducing tau hyperphosphorylation remains unclear and therefore no effective treatment options are currently available. We here show that employing single prolonged stress (SPS), as a consensus PTSD model, induced a typical anxiety and abnormal hyperphosphorylation of tau at Ser202/Thr205 (AT8) and Ser404 but not at Ser199 and Ser396 in the hippocampus compared to the control rats. Furthermore, there was a decrease in the level of inactivated phosphorylated GSK-3β at Ser9, an increase in the level of activated phosphorylated GSK-3β at Thr216 and an obvious decrease in the level of activated phosphorylated ERK1/2, but no alterations in CaMKII and PP2A in hippocampus of SPS rats. On the other hand, the levels of both phosphorylated AKT and total SGK1, stress- and GSK-3β/ERK1/2-related proteins, were down-regulated. Interestingly, Overexpression of SGK1 increased the level of phosphorylated ERK1/2 and led to tau hyperphosphorylation at Ser199 and Ser396. These findings suggest that SPS exposure results in differential tau phosphorylation at different sites probably due to incongruous action between AKT-related GSK-3β activation and SGK1-related ERK1/2 inactivation, suggesting a link between SPS-induced PTSD and AD-associated tau pathogenic mechanisms.

Drug interactions with dementia-related pathophysiological pathways worsen or prevent dementia

Many risk factors are known to induce or precipitate dementia. Drugs acting via different mechanisms can modulate cognitive performance and exert either beneficial or deleterious effects on cognition through functional or neuropathological mechanisms. This review discusses the association between several classes of drugs and cognitive impairment and dementia risk. These drugs can be divided into drugs targeting CNS disorders (e.g., anticholinergic drugs, antiepileptics, antipsychotics, benzodiazepines, and opioids) and drugs targeting non‐CNS disorders (e.g., antidiabetics, antihypertensives, proton pump inhibitors, and statins). Furthermore, we sought to highlight the pharmacological mechanisms underlying their possible detrimental or beneficial effects on cognition. Anticholinergic and antiepileptic drugs were excluded from this review because their effects on cognition are well known. Studies investigating benzodiazepines have revealed an increased risk of dementia. Conclusions on dementia risk or cognitive impairment regarding opioids and antipsychotic drugs are difficult to draw. These different classes appear to impair cognition not by a single clear mechanism of action specific to each class but by several relatively interdependent and interconnected mechanisms (e.g., impaired neurotransmission, neuroinflammation, neuronal death, oxidative stress, or interactions with dementia‐related pathways). The dementia risk initially associated with the use of proton pump inhibitors might have been overestimated. In contrast, statins, antihypertensive medications, and antidiabetics could potentially decrease the risk of dementia and cognitive impairment by acting in ways opposite to the mechanisms cited above.

Linked Articles

This article is part of a themed section on Therapeutics for Dementia and Alzheimer's Disease: New Directions for Precision Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.18/issuetoc

Neurocognitive and psychiatric comorbidities of posttraumatic stress disorder among older veterans: A systematic review

OBJECTIVES

Posttraumatic stress disorder (PTSD) is associated with neurocognitive and psychiatric comorbidities, and older adults experience comorbid illnesses disproportionately. Little is known about the comorbidities of PTSD among older veterans. This systematic review examines the prevalence, incidence, and patterns of neurocognitive and psychiatric comorbidities of PTSD among older veterans and explores the factors associated with these comorbidities.

METHODS

A systematic literature review was performed using PubMed, CINAHL, and PsycINFO databases. The search was limited to peer-reviewed articles published in English from January 1980 to October 2018. Eligible studies examined the comorbid neurocognitive and psychiatric disorders of PTSD among veterans aged 60 and older.

RESULTS

Twenty-four studies met the criteria for inclusion. The risk for dementia was higher in veterans with PTSD than those without PTSD; hazard ratios ranged from 1.21 to 1.77. Depressive disorder was the most prevalent psychiatric comorbidity with estimates ranging from 33% to 52.3%, followed by generalized anxiety disorder (14%-15%) and substance use disorders (1.9%-11.3%). Factors consistently associated with PTSD comorbidities included age, combat-related exposures, clinical conditions, and health-related and psychosocial outcomes.

CONCLUSIONS

Despite heterogeneity in research designs and methodological limitations, this review highlights the need to consider comorbid neurocognitive and psychiatric disorders among older veterans with PTSD in order to individualize care approaches. Future research should incorporate factors associated with neurocognitive and psychiatric comorbidities of PTSD into study designs that can help improve prediction of comorbidity and generate evidence for developing and implementing tailored treatments in older veterans.

Genomics of posttraumatic stress disorder in veterans: Methods and rationale for Veterans Affairs Cooperative Study #575B

OBJECTIVES

Heritability in the risk for developing posttraumatic stress disorder (PTSD) has been established, but most genome-wide association studies (GWASs) of PTSD involve relatively small sample sizes and limited identification of associated genetic loci. This report describes the methodology of a Veterans Affairs (VA) Cooperative Studies Program GWAS of PTSD among combat-exposed U.S. veterans.

METHODS

Probable cases (with PTSD) and probable controls (without PTSD) were identified from among veterans enrolled in the VA Million Veteran Program (MVP) with an algorithm developed using questionnaire responses and electronic health record information. This algorithm, based on a statistical model, relied on medical chart reviews as a reference standard and was refined using telephone interviews. Subsequently, to evaluate the impact of probabilistic phenotyping on statistical power, the threshold probability for case-control selection was varied in simulations.

RESULTS

As of September 2018, >695,000 veterans have enrolled in MVP. For current analyses, genotyping data were available for >353,000 participants, including >83,000 combat-exposed veterans. A threshold probability of 0.7 for case and control designation yielded an interim >16,000 cases and >33,000 controls.

CONCLUSIONS

A formal methodological approach was used to identify cases and controls for subsequent GWAS analyses to identify genetic risk loci for PTSD.

Stress and Alzheimer's disease

Alzheimer's disease (AD) is the leading cause of dementia worldwide. Due to demographic change in higher income countries and rising life expectancy in middle- and low-income countries, the prevalence of AD will increase significantly in the coming years. In the search for effective AD prevention, the role of stress in the development of AD has come into focus. There is increasing evidence that chronic exposure to stress is a risk factor for AD and may also adversely affect the course of the disease. In our review, we present the current literature on the association of specific personality traits and the risk of developing AD. We also report on findings on dementia risk in patients with posttraumatic stress disorder. Furthermore, we describe the role of anxiety symptoms in AD and give a brief overview over the biological mechanisms behind the association of stress and AD.

Depression and Antidepressants as Potential Risk Factors in Dementia: A Systematic Review and Meta-analysis of 18 Longitudinal Studies

OBJECTIVE

To investigate whether depression and/or antidepressants can be a potential risk factor for the development of dementia and mild cognitive impairment (MCI).

DESIGN

Systematic review and meta-analysis of longitudinal studies.

SETTING AND PARTICIPANTS

Community or clinical settings. Participants included patients with depression, antidepressant users, and the general population.

MEASURES

Longitudinal studies evaluating the risks of dementia or MCI in patients with depression and/or antidepressant users were identified from the OVID database. The outcomes were the number of patients who developed dementia or MCI among the antidepressant users and nonusers. Relative risk (RR) with 95% confidence interval (95% CI) was used to evaluate the association between the use of antidepressants and the risk of dementia and MCI. Meta-analysis was used for combining the effect sizes of individual studies, and the heterogeneity test was performed. Risk of bias and reporting quality of included studies was assessed. Subgroup analyses were conducted for different types of antidepressants.

RESULTS

A total of 18 studies with 2,119,627 participants with mean age ranging from 55 to 81 years were included. Among patients with depression, antidepressant users showed a significantly higher risk of dementia (RR = 1.37, 95% CI = 1.11-1.70) and MCI (RR = 1.20, 95% CI = 1.02-1.42) than the nonusers. Besides, patients with depression who used antidepressants and who did not use antidepressants also showed significantly higher risk of dementia than the general population (RR = 1.50, 95% CI = 1.26-1.78, and RR = 1.31, 95% CI = 1.15-1.51, respectively).

CONCLUSIONS/IMPLICATIONS

Patients with depression are associated with a higher risk of dementia, and the use of antidepressants is not shown to be a protective factor of dementia. Further large-scale trials are required for investigation of the benefit-risk ratio between depression relapse and dementia when prescribing antidepressants.

Clinically significant anxiety as a risk factor for dementia in the elderly community

OBJECTIVE

To evaluate whether clinically significant anxiety is an independent risk factor for dementia, taking into account both depression among potentially confounding factors and the competing risk of death.

METHOD

During the Zaragoza Dementia and Depression (ZARADEMP) study, a random sample of community dwellers aged 55 years or older was assessed (n = 4803), and a two-wave, 4.5-year follow-up was completed. Geriatric Mental State (GMS)-AGECAT criteria were used to diagnose anxiety and DSM-IV criteria were applied to diagnose incident dementia. The multivariate Fine and Gray regression model was implemented to calculate dementia risk.

RESULTS

Compared with non-cases (GMS-AGECAT criteria), the incidence rate of dementia was significantly higher in subcases of anxiety, and particularly significant in the cases of anxiety (incidence rate ratio (IRR): 2.77; P = 0.010). Cases of anxiety, but not subcases, at baseline were significantly associated with dementia risk (adjusted subdistribution hazard ratio (SHR): 2.7; P = 0.019).

CONCLUSION

Clinically significant anxiety is associated with an almost threefold increase in the risk of dementia in the population, even when controlling for depression and considering mortality in the competing risks model.

Trauma and Aging

PURPOSE OF REVIEW

The aim of this paper is to present a succinct summary of the major scientific findings on trauma, posttraumatic stress disorder (PTSD), and aging over the past few years.

RECENT FINDINGS

There have been several reports from longitudinal investigations using representative samples of veterans regarding traumatic exposure and subsequent effects on health and functioning. There has also been further documentation of the significant association between PTSD and dementia as well as accelerated aging in late life. Several studies indicate that older adults with PTSD are at risk of not receiving timely and appropriate mental health treatment, indicating that targeted outreach could be helpful in increasing service use and improving care. The current knowledge base would benefit from more research on traumatized older adults from non-industrialized countries, as well as those in North America from diverse backgrounds, including ethnic and racial minorities, women, and those with cognitive impairments. Studies limited to adults aged 65 and over as well as those addressing disparities in the availability of mental health-related services within this population are warranted.

Dementia, post-traumatic stress disorder and major depressive disorder: a review of the mental health risk factors for dementia in the military veteran population

BACKGROUND

Dementia is currently incurable, irreversible and a major cause of disability for the world's older population. The association between mental health difficulties, such as post-traumatic stress disorder (PTSD) and major depressive disorder (MDD), and dementia has a long history within the civilian population. Despite the increased importance of this link within the military veteran population, who suffer a greater propensity of mental health difficulties and consist largely of over 65s, attention is only recently being paid to the salience of such an association for this group. This paper aims to explore the relationship between PTSD and MDD with dementia within the military veteran population.

METHOD

A systematic review was conducted on articles from 1990 to July 2016 on MEDLINE, EMBASE, EBSCO and Web of Science electronic databases with an update conducted in February 2017.

RESULTS

Six empirical studies were identified from the review, the majority of which originated from the USA. Five of the studies asserted that veterans with a diagnosis of either PTSD or MDD are at a significantly greater risk of developing dementia than 'healthy' controls. The final study, conducted in Australia, found only a small, but non-significant, correlation between earlier MDD and future dementia, but no concurrent correlation.

CONCLUSIONS

While causality cannot be determined, it is likely that PTSD and depressive disorders are related to an increased risk of dementia in military veterans. Potential pathological explanations and risk factors are reviewed and the clinical and neuroscience implications of these findings are explored.

A Systematic Review and Meta-Analysis of the Risk of Dementia Associated with Benzodiazepine Use, After Controlling for Protopathic Bias

BACKGROUND

Benzodiazepine use is highly prevalent in elderly and late middle-aged populations and may be associated with an increased risk of dementia. Observational studies have suggested that benzodiazepine use may increase the risk of dementia, however there have been significant concerns regarding protopathic bias in these studies, precluding conclusive findings.

OBJECTIVE

The aim of our study was to investigate the risk of dementia associated with the use of benzodiazepines in elderly patients, after controlling for protopathic bias.

METHODS

We identified observational studies with more than 50 cases, adequate assessment of benzodiazepine exposure, and reliable dementia diagnosis ascertainment, from the MEDLINE, PubMed, EMBASE, CINAHL, LILACS and CENTRAL electronic databases through to 5 June 2018, with no language limits. The association of any current or former use of short- or long-acting benzodiazepines with incident dementia was analysed. A subgroup analysis was performed by the introduction of lag time to assess the effect of protopathic bias. We also performed analyses considering the effect of higher benzodiazepine cumulative doses and adjustment for psychiatric covariates. Study quality was investigated using the Newcastle-Ottawa Scale.

RESULTS

We identified 15 studies reported in 14 articles, involving 159,090 cases. Ever use of benzodiazepines was associated with a significantly increased risk of dementia [odds ratio (OR) 1.39, 95% confidence interval (CI) 1.21-1.59]. Those studies that implemented the longest lag times of ≥ 5 years, and hence most likely to overcome protopathic bias, found a risk estimate that was marginally attenuated, but still significant (OR 1.30, 95% CI 1.14-1.48). Long-acting benzodiazepines were associated with a marginally higher magnitude risk (OR 1.21, 95% CI 0.99-1.49) than short-acting benzodiazepines (OR 1.13, 95% CI 1.02-1.26), although the former failed to reach statistical significance (p = 0.059).

CONCLUSIONS

Our findings indicate that the association between benzodiazepine use and dementia incidence is not purely an artefact due to protopathic bias. Reduction of inappropriate benzodiazepine prescription is likely to attenuate dementia risk.

Posttraumatic Stress Disorder in the Elderly

Posttraumatic stress disorder (PTSD) can occur at any point in the life span and can last for decades. Chronic PTSD can affect quality of life and have a negative impact on physical function and health in the elderly and may be associated with premature aging and dementia. It is critical that clinicians screen for trauma-based symptoms and to treat as appropriate.