Medial temporal tau predicts memory decline in cognitively unimpaired elderly

Assessing the Effects of Metabolic Disruption, Body Mass Index and Inflammation on Depressive Symptoms in Post-COVID-19 Condition: A Randomized Controlled Trial on Vortioxetine

INTRODUCTION

To date, there are no therapeutics that have gained regulatory approval by the United States Food and Drug Administration (FDA) for the treatment of post-COVID-19 condition (PCC), a debilitating condition characterized by cognitive impairment and mood symptoms. Additionally, persistent inflammation, metabolic dysfunction, and risks associated with an elevated body mass index (BMI) have been observed. Herein, we aimed to assess the efficacy of vortioxetine in improving depressive symptoms among individuals with PCC,  as modulated by inflammation, metabolic dysfunction, and BMI.

METHODS

In this post-hoc analysis, we present preliminary data obtained from an 8-week randomized, double-blind, placebo-controlled trial. Participants included  adults aged 18 years and older residing in Canada who were experiencing symptoms of World Health Organization (WHO)-defined PCC. Recruitment began November 2021 and ended January 2023. Of the 200 participants enrolled, 147 were randomized (1:1) to receive vortioxetine (5-20 mg, n = 73) or placebo (n = 74) for daily treatment under double-blind conditions. The primary outcome measure was the change from baseline to endpoint in the 16-Item Quick Inventory of Depressive Symptomatology Self-Report Questionnaire (QIDS-SR-16).

RESULTS

Our findings revealed significant effects for time (χ2 = 9.601, p = 0.002), treatment (χ2 = 9.135, p = 0.003), and the treatment × time × CRP × TG-HDL × BMI interaction (χ2 = 26.092, p < 0.001) on PCC-related depressive symptoms in the adjusted model. Moreover, the between-group analysis showed a significant improvement with vortioxetine at endpoint as compared to placebo (mean difference = - 5.41, SEM = 1.335, p < 0.001).

CONCLUSION

Overall, vortioxetine significantly improved depressive symptoms among participants with PCC in the adjusted model. Notably, individuals with baseline markers of increased inflammation, metabolic disruption, and elevated BMI exhibited a more pronounced antidepressant effect at endpoint.

TRIAL REGISTRATION NUMBER

NCT05047952 (ClinicalTrials.gov).

Biomarker-based staging of Alzheimer disease: rationale and clinical applications

Disease staging, whereby the spatial extent and load of brain pathology are used to estimate the severity of Alzheimer disease (AD), is pivotal to the gold-standard neuropathological diagnosis of AD. Current in vivo diagnostic frameworks for AD are based on abnormal concentrations of amyloid-β and tau in the cerebrospinal fluid or on PET scans, and breakthroughs in molecular imaging have opened up the possibility of in vivo staging of AD. Focusing on the key principles of disease staging shared across several areas of medicine, this Review highlights the potential for in vivo staging of AD to transform our understanding of preclinical AD, refine enrolment criteria for trials of disease-modifying therapies and aid clinical decision-making in the era of anti-amyloid therapeutics. We provide a state-of-the-art review of recent biomarker-based AD staging systems and highlight their contributions to the understanding of the natural history of AD. Furthermore, we outline hypothetical frameworks to stage AD severity using more accessible fluid biomarkers. In addition, by applying amyloid PET-based staging to recently published anti-amyloid therapeutic trials, we highlight how biomarker-based disease staging frameworks could illustrate the numerous pathological changes that have already taken place in individuals with mildly symptomatic AD. Finally, we discuss challenges related to the validation and standardization of disease staging and provide a forward-looking perspective on potential clinical applications.

In vivo tau is associated with change in memory and processing speed, but not reasoning, in cognitively unimpaired older adults

The relationship between tau deposition and cognitive decline in cognitively healthy older adults is still unclear. The tau PET tracer 18F-MK-6240 has shown favorable imaging characteristics to identify early tau deposition in aging. We evaluated the relationship between in vivo tau levels (18F-MK-6240) and retrospective cognitive change over 5 years in episodic memory, processing speed, and reasoning. For tau quantification, a set of regions of interest (ROIs) was selected a priori based on previous literature: (1) total-ROI comprising selected areas, (2) medial temporal lobe-ROI, and (3) lateral temporal lobe-ROI and cingulate/parietal lobe-ROI. Higher tau burden in most ROIs was associated with a steeper decline in memory and speed. There were no associations between tau and reasoning change. The novelty of this finding is that tau burden may affect not only episodic memory, a well-established finding but also processing speed. Our finding reinforces the notion that early tau deposition in areas related to Alzheimer's disease is associated with cognitive decline in cognitively unimpaired individuals, even in a sample with low amyloid-β pathology.