Posttraumatic stress disorder symptom severity is associated with reduced Montreal Cognitive Assessment scores in a sample of Vietnam War Veterans

PTSD moderates the association between subjective cognitive decline and Alzheimer's disease biomarkers in older veterans

OBJECTIVES

Post-traumatic stress disorder (PTSD) and subjective cognitive decline (SCD) are independent risk factors for Alzheimer's disease (AD) and dementia, but the association of their interaction on AD biomarkers have yet to be characterized. This study aimed to examine the impact of PTSD on the association between SCD and tau and amyloid positron emission tomography (PET) as well as global cognition in older Veterans.

METHOD

This study included 87 Vietnam-Era Veterans without dementia (42 with PTSD; 45 without PTSD) from the Department of Defense-Alzheimer's Disease Neuroimaging Initiative. All participants had both tau and amyloid PET imaging as well as cognitive testing. SCD was measured using the Everyday Cognition questionnaire.

RESULTS

While SCD was associated with tau PET, amyloid PET, and global cognition, PTSD moderated these associations for tau and amyloid PET levels. Specifically, Veterans without PTSD had a stronger positive relationship between SCD and AD biomarkers when compared to those with PTSD.

CONCLUSION

Higher SCD was associated with greater tau and amyloid burden and worse cognitive performance across the sample, though the tau and amyloid associations were stronger for Veterans without PTSD. Results highlight the potential benefit of comprehensive clinical assessments including consideration of mental health among older Veterans with SCD to understand the underlying cause of the cognitive concerns. Additionally, more work is needed to understand alternative mechanisms driving SCD in older Veterans with PTSD.

UNITE Project: understanding neurocognitive impairment after trauma exposure-study protocol of an observational study in Christchurch, New Zealand

INTRODUCTION

Our previous research has demonstrated significant cognitive effects of earthquake exposure 2-3 years following the Canterbury earthquake sequence of 2011. Such impairment has major implications for a population trying to recover, and to rebuild, a devastated city. This study aims to examine psychological, cognitive and biological factors that may contribute to subjective cognitive difficulties in a large group of individuals exposed to the Canterbury earthquake sequence.

METHODS AND ANALYSIS

Two-hundred earthquake-exposed participants from an existing large cohort study (Christchurch Health and Development Study, CHDS) will be recruited. Inclusion is based on results of online screening of the CHDS cohort, using the Cognitive Failures Questionnaire. Individuals scoring the highest (n=100) and lowest (n=100), representing the highest and lowest levels of subjective cognitive impairment, are selected. Exclusions are: psychotic/bipolar disorders, serious substance/alcohol dependence, chronic medical conditions, pregnancy and previous serious head injury. Participants will undergo a half-day assessment including clinician-rated interviews, self-report measures, objective and subjective cognitive assessments, blood sample collection and physical measurements. The primary analysis will compare cognitive, psychological and biological measures in 'high' and 'low' subjective cognitive impairment groups. The study will have power (p<0.05, α=0.8) to show a difference between groups of 0.4 SD on any variable.

ETHICS AND DISSEMINATION

Ethical approval for this study was granted by the New Zealand Health and Disability Ethics Committee. The online screening component of the study received ethical approval on 1 April 2021 (16/STH/188, PAF 7), and the main study (subsequent to screening) received approval on 16 August 2021 (Northern A 21/NTA/68). All participants provide written informed consent. Findings will be disseminated initially to the CHDS cohort members, the wider Canterbury community, and then by publication in scientific journals and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05090046).

Posttraumatic stress symptom severity predicts cognitive decline beyond the effect of Alzheimer's disease biomarkers in Veterans

Chronic stress is a risk factor for dementia but whether it explains unique variance in cognitive decline in older adults above Alzheimer's disease (AD) biomarkers is unknown. In a preclinical cohort of Vietnam Veterans, we examined the relationship between posttraumatic stress disorder (PTSD) symptom severity, AD biomarkers of beta-amyloid (Aβ) and tau, and change in cognitive performance on two widely-used screeners, the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). Analyses indicated that PTSD symptom severity was associated with a greater decline on the MMSE (p < 0.04) and MoCA (p < 0.024) after adjusting for biomarkers of AD, notably on the attention scale of the MoCA and the memory index of the MMSE. These analyses survived multiple comparison corrections. Taken together, PTSD symptom severity is associated with accelerated cognitive decline. Treating PTSD should be considered instrumental to maintaining cognitive function as adults age.

Montreal Cognitive Assessment scores of Veterans and Canadian Armed Forces personnel seeking mental health treatment

LAY SUMMARY

The Montreal Cognitive Assessment (MoCA) is a test of mild cognitive impairment that is commonly administered to military personnel seeking mental health treatment. However, there is little research on the average MoCA score for military Veterans. This study looked at MoCA scores provided by Canadian Armed Forces members and Veterans receiving services for an operational-related mental health condition. Scores below the cut-off for mild cognitive impairment were not uncommon and were related to education level, as well as to severity of posttraumatic stress disorder and depression. These findings will help clinicians better contextualize score variation among clients.