
Michael J LyonsBoston University | BU · Department of Psychology
Michael J Lyons
About
492
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September 1986 - present
Publications
Publications (492)
Background
Early identification of Alzheimer’s disease (AD) risk prior to irreversible brain damage is critical for improving the success of interventions and treatment. Cortical thickness is a macrostructural measure typically used to assess AD neurodegeneration. However, cortical microstructural changes appear to precede macrostructural atrophy a...
Background
Chronic pain leads to tau accumulation and hippocampal atrophy in mice. Tau accumulation in the locus coeruleus (LC) precedes medial temporal accumulation in humans. Here we provide one of the first human studies examining the association of chronic pain with hippocampal volume, LC integrity, and Alzheimer’s Disease (AD)‐related plasma b...
Background
Early identification of Alzheimer’s disease (AD) risk prior to irreversible brain damage is critical for improving the success of interventions and treatment. Cortical thickness is a macrostructural measure typically used to assess AD neurodegeneration. However, cortical microstructural changes appear to precede macrostructural atrophy a...
Background
Chronic pain leads to tau accumulation and hippocampal atrophy in mice. Tau accumulation in the locus coeruleus (LC) precedes medial temporal accumulation in humans. Here we provide one of the first human studies examining the association of chronic pain with hippocampal volume, LC integrity, and Alzheimer’s Disease (AD)‐related plasma b...
Objectives:
Childhood disadvantage is associated with lower general cognitive ability (GCA) and brain structural differences in midlife and older adulthood. However, the neuroanatomical mechanisms underlying childhood disadvantage effects on later-life GCA remain poorly understood. Although total surface area (SA) has been linked to lifespan GCA d...
Neurofilament light chain (NfL) levels in circulation have been established as a sensitive biomarker of neuro-axonal damage across a range of neurodegenerative disorders. Elucidation of the genetic architecture of blood NfL levels could provide new insights into molecular mechanisms underlying neurodegenerative disorders. In this meta-analysis of g...
Background:
Chronic pain leads to tau accumulation and hippocampal atrophy, which may be moderated through inflammation. In older men, we examined associations of chronic pain with AD-related plasma biomarkers and hippocampal volume as moderated by systemic inflammation.
Methods:
Participants were men without dementia. Chronic pain was defined a...
Multivariate network‐based analytic methods such as weighted gene co‐expression network analysis are frequently applied to human and animal gene‐expression data to estimate the first principal component of a module, or module eigengene (ME). MEs are interpreted as multivariate summaries of correlated gene‐expression patterns and network connectivit...
INTRODUCTION
The amyloid cascade hypothesis predicts that amyloid-beta (Aβ) aggregation drives tau tangle accumulation. We tested competing causal and non-causal hypotheses regarding the direction of causation between Aβ40 and Aβ42 and total Tau (t-Tau) plasma biomarkers.
METHODS
Plasma Aβ40, Aβ42, t-Tau, and neurofilament light chain (NFL) were m...
Multivariate network-based analytic methods such as weighted gene co-expression network analysis are being increasingly applied to human and animal gene-expression data to estimate module eigengenes (MEs). MEs represent multivariate summaries of correlated gene-expression patterns and network connectivity across genes within a module. Although this...
Background
Plasma neurofilament light chain (NfL) is a promising biomarker of neurodegeneration with potential clinical utility in monitoring the progression of neurodegenerative diseases. However, the cross-sectional associations of plasma NfL with measures of cognition and brain have been inconsistent in community-dwelling populations.
Methods
W...
Background
The study explores whether frailty at midlife predicts mortality and levels of biomarkers associated with Alzheimer’s disease and related dementias (ADRD) and neurodegeneration by early old age. We also examine the heritability of frailty across this age period.
Methods
Participants were 1,286 community-dwelling men from the Vietnam Era...
Although the cerebellum contributes to higher-order cognitive and emotional functions relevant to posttraumatic stress disorder (PTSD), prior research on cerebellar volume in PTSD is scant, particularly when considering subregions that differentially map on to motor, cognitive, and affective functions. In a sample of 4215 adults (PTSD n = 1642; Con...
Background
Neurofilament light chain (NfL) levels in circulation have been established as a sensitive biomarker of neuro‐axonal damage across a range of neurodegenerative disorders. Elucidation of the genetic architecture of blood NfL levels and its genetic correlation with neurological traits could therefore provide new insights into shared molecu...
Background
Frailty refers to a person’s physical and functional capabilities and increases during aging. Abnormal white matter (AWM; e.g., hyperintensities on T2‐weighted MRI) is a neuroimaging marker of small‐vessel vascular disease associated with increased risk of Alzheimer’s Disease and related dementias. While some studies have found associati...
Background
Predicted brain age difference (PBAD) scores are novel metrics which compare chronological age to age predicted from neuroimaging data. PBADs are highly relevant to Alzheimer’s disease (AD) and cognitive aging. Individuals with AD have predicted brain ages about 10 years older than their chronological age (Franke et al. 2010). Less is kn...
Objective
US forces used Agent Orange (AO) during the Vietnam War and continued to store/test it at other locations after the war. AO is a powerful herbicide including dioxin, a highly toxic ingredient classified as a human carcinogen. The National Academies of Sciences, Engineering, and Medicine periodically review the literature on the health eff...
INTRODUCTION
Despite their increased application, the heritability of Alzheimer's disease (AD)–related blood‐based biomarkers remains unexplored.
METHODS
Plasma amyloid beta 40 (Aβ40), Aβ42, the Aβ42/40 ratio, total tau (t‐tau), and neurofilament light (NfL) data came from 1035 men 60 to 73 years of age (μ = 67.0, SD = 2.6). Twin models were used...
Importance:
Subjective memory concern has long been considered a state-related indicator of impending cognitive decline or dementia. The possibility that subjective memory concern may itself be a heritable trait is largely ignored, yet such an association would substantially confound its use in clinical or research settings.
Objective:
To assess...
Some evidence suggests a biphasic pattern of changes in cortical thickness wherein higher, rather than lower, thickness is associated with very early Alzheimer's disease (AD) pathology. We examined whether integrating information from AD brain signatures based on mean diffusivity (MD) can aid in the interpretation of cortical thickness/volume as a...
Background:
Childhood disadvantage is a prominent risk factor for cognitive and brain aging. Childhood disadvantage is associated with poorer episodic memory in late midlife and functional and structural brain abnormalities in the default mode network (DMN). Although age-related changes in DMN are associated with episodic memory declines in older...
Background:
Fine particulate matter (PM2.5) and nitrogen dioxide (NO2) measures of ambient air pollution are associated with accelerated age-related cognitive impairment, and Alzheimer's disease and related dementias (ADRD).
Objective:
We examined associations between air pollution, four cognitive factors, and the moderating role of apolipoprote...
Aging‐related episodic memory (EM) decline and Alzheimer’s disease (AD)‐related brain changes begin in late middle age around age 60. However, rate and severity of cognitive decline do not consistently correspond to the extent of neuropathological changes, suggesting a high degree of heterogeneity in EM trajectories. We tested if brain maintenance...
Cortical surface area, cortical thickness, and hippocampal volume are well‐studied in relation to later life cognitive impairments and AD. Fewer studies have investigated how white mater microstructure relates to cognition in late life. Existing work has focused on fractional anisotropy (FA) and mean diffusivity (MD) measures that are thought to ca...
Composite scores of MRI‐based brain regions associated with Alzheimer’s disease (AD) pathology, commonly termed ‘AD signatures,' are tools developed to identify brain changes specific to mild AD. In recent work from our group, we found that a novel diffusion‐based cortical mean diffusivity (MD) signature among cognitively normal adults in their 50s...
Composite scores of MRI‐based brain regions associated with Alzheimer’s disease (AD) pathology, commonly termed ‘AD signatures’, are tools developed to identify brain changes specific to mild AD. We found that a novel diffusion‐based cortical mean diffusivity (MD) signature among cognitively normal adults in their 50s aided prediction of 12‐year pr...
Objectives
Abnormal tau, a hallmark Alzheimer’s disease (AD) pathology, may appear in the locus coeruleus (LC) decades before AD symptom onset. Reports of subjective cognitive decline are also often present prior to formal diagnosis. Yet, the relationship between LC structural integrity and subjective cognitive decline has remained unexplored. Here...
Background
Blood-based neurofilament light chain (NfL) is a promising biomarker of neurodegeneration across multiple neurodegenerative diseases. However, blood-based NfL is highly associated with renal function in older adults, which leads to the concern that blood-based NfL levels may be influenced by renal function, rather than neurodegeneration...
Background: Neurofilament light chain (NfL) levels in circulation have been established as a sensitive biomarker of neuro-axonal damage across a range of neurodegenerative disorders. Elucidation of the genetic architecture of blood NfL levels and its genetic correlation with neurological traits could therefore provide new insights into shared molec...
Background
Studies have investigated white matter microstructure in relation to late-life cognitive impairments, with fractional anisotropy (FA) and mean diffusivity (MD) measures thought to capture demyelination and axonal degradation. However, new post-processing methods allow isolation of free water (FW), which captures extracellular fluid contr...
Background
The amyloid‐tau‐neurodegeneration (ATN) framework has led to an increased focus on Alzheimer’s disease (AD) biomarkers. The costs and invasiveness of methods relying on cerebrospinal fluid or positron emission tomography imaging have led to efforts to develop sensitive blood‐based biomarkers. Although AD is highly heritable, the biometri...
Background
The cerebellum critically contributes to higher-order cognitive and emotional functions such fear learning and memory. Prior research on cerebellar volume in PTSD is scant and has neglected neuroanatomical subdivisions of the cerebellum that differentially map on to motor, cognitive, and affective functions.
Methods
We quantified cerebe...
Background and objectives:
Vascular theories of cognitive aging have focused on macrovascular changes and cognitive decline. However, according to the artery size hypothesis, microvascular changes, such as those that underlie changes in erectile function, may also play an important role in contributing to cognitive decline. Thus, we examined assoc...
Posttraumatic stress disorder (PTSD) is a heritable (h² = 24–71%) psychiatric illness. Copy number variation (CNV) is a form of rare genetic variation that has been implicated in the etiology of psychiatric disorders, but no large-scale investigation of CNV in PTSD has been performed. We present an association study of CNV burden and PTSD symptoms...
The amyloid-tau-neurodegeneration (ATN) framework has led to an increased focus on Alzheimers disease (AD) biomarkers. The cost and invasiveness of obtaining biomarkers via cerebrospinal fluid has motivated efforts to develop sensitive blood-based biomarkers. Although AD is highly heritable, the biometric genetic and environmental etiology of blood...
INTRODUCTION
Genetic influences on the stability of subjective memory concerns (SMC) may confound its interpretation as a state-related risk indicator.
METHODS
We estimated genetic influences on SMC and SMC change from average ages 38 to 67, genetic correlations of SMC with memory and depressive symptoms at average ages 56, 62, and 67, and correla...
We tested the causality between education and smoking using the natural experiment of discordant twin pairs allowing to optimally control for background genetic and childhood social factors. Data from 18 cohorts including 10,527 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs discordant for education and smoking were analyzed by linear fixe...
Background
Composite scores of MRI-derived metrics in brain regions associated with Alzheimer’s disease (AD), commonly termed ‘AD signatures,’ have been developed to distinguish early AD-related atrophy from normal age-associated changes. Diffusion-based gray matter signatures may be more sensitive to early AD-related changes compared to thickness/...
Cognitive reserve and related constructs are valuable for aging-related research, but consistency and clarification of terms is needed as there is still no universally agreed upon nomenclature. We propose a new set of definitions for the concepts of reserve, maintenance, and resilience, and we invoke parallel concepts for each that are applicable t...
Objective
To determine associations of alcohol use with cognitive aging among middle-aged men.
Method
1,608 male twins (mean 57 years at baseline) participated in up to three visits over 12 years, from 2003–2007 to 2016–2019. Participants were classified into six groups based on current and past self-reported alcohol use: lifetime abstainers, form...
Background
Posttraumatic stress disorder (PTSD) is heritable and a potential consequence of exposure to traumatic stress. Evidence suggests that a quantitative approach to PTSD phenotype measurement and incorporation of lifetime trauma exposure (LTE) information could enhance the discovery power of PTSD genome-wide association studies (GWAS).
Meth...
Circulating total-tau levels can be used as an endophenotype to identify genetic risk factors for tauopathies and related neurological disorders. Here, we confirmed and better characterized the association of the 17q21 MAPT locus with circulating total-tau in 14,721 European participants and identified three novel loci in 953 African American parti...
Magnetic resonance imaging data are being used in statistical models to predicted brain ageing (PBA) and as biomarkers for neurodegenerative diseases such as Alzheimer’s Disease. Despite their increasing application, the genetic and environmental etiology of global PBA indices is unknown. Likewise, the degree to which genetic influences in PBA are...
Objective
Cognitive practice effects (PEs) can delay detection of progression from cognitively unimpaired to mild cognitive impairment (MCI). They also reduce diagnostic accuracy as suggested by biomarker positivity data. Even among those who decline, PEs can mask steeper declines by inflating cognitive scores. Within MCI samples, PEs may increase...
Objective
Alzheimer’s disease (AD) is highly heritable, and AD polygenic risk scores (AD-PRSs) have been derived from genome-wide association studies. However, the nature of genetic influences very early in the disease process is still not well known. Here we tested the hypothesis that an AD-PRSs would be associated with changes in episodic memory...
Introduction
Practice effects (PEs) on cognitive tests obscure decline, thereby delaying detection of mild cognitive impairment (MCI). Importantly, PEs may be present even when there are performance declines, if scores would have been even lower without prior test exposure. We assessed how accounting for PEs using a replacement‐participants method...
The locus coeruleus (LC) is one of the earliest sites of tau pathology, making it a key structure in early Alzheimer's disease (AD) progression. As the primary source of norepinephrine for the brain, reduced LC integrity may have negative consequences for brain health, yet macrostructural brain measures (e.g. cortical thickness) may not be sensitiv...
The volume of subcortical structures represents a reliable, quantitative, and objective phenotype that captures genetic effects, environmental effects such as trauma, and disease effects such as posttraumatic stress disorder (PTSD). Trauma and PTSD represent potent exposures that may interact with genetic markers to influence brain structure and fu...
Background
The locus coeruleus (LC) serves as the primary source of norepinephrine for the brain. Findings that the LC is one of the earliest sites of tau pathology make it a key structure in the early stages of Alzheimer’s disease (AD) progression. An important question is whether measures of LC integrity are associated with indexes of brain struc...
Background:
Genome-wide association studies are instrumental in quantifying genetic influences underlying Alzheimer's disease (AD), and applications of polygenic scores derived from association studies have already shed light on early disease pathology. For example, AD polygenic scores (AD-PGS) are associated with amnestic mild cognitive impairmen...
The locus coeruleus (LC) is a brainstem region involved in regulating pain. Chronic pain is common in older adulthood, but no studies have examined its association with the LC in humans. We used neuromelanin-sensitive imaging to study differences in LC integrity in older adults with and without chronic pain. Chronic pain was assessed in community-d...
Objectives
Major Depressive Disorder (MDD) is a complex neuropsychiatric disease with known genetic associations, but without known links to rare variation in the human genome. Here we aim to identify rare genetic variants associated with MDD using deep whole-genome sequencing data in an independent population.
Methods
We report the sequencing of...
Background and aims
Smoking is associated with increased risk for brain aging/atrophy and dementia. Few studies have examined early associations with brain aging. This study aimed to measure whether adult men with a history of heavier smoking in early midlife would have older than predicted brain age 16 to 28 years later.
Design
Prospective cohort...
Because longitudinal studies of aging typically lack cognitive data from earlier ages, it is unclear how general cognitive ability (GCA) changes throughout the life course. In 1,173 Vietnam Era Twin Study of Aging (VETSA) participants, we assessed young adult GCA at average age 20 and current GCA at three VETSA assessments beginning at average age...
Despite their increasing application, the genetic and environmental etiology of global predicted brain ageing (PBA) indices is unknown. Likewise, the degree to which genetic influences in PBA are longitudinally stable and how PBA changes over time are also unknown. We analyzed data from 734 men from the Vietnam Era Twin Study of Aging with repeated...
A growing number of studies have examined alterations in white matter organization in people with posttraumatic stress disorder (PTSD) using diffusion MRI (dMRI), but the results have been mixed which may be partially due to relatively small sample sizes among studies. Altered structural connectivity may be both a neurobiological vulnerability for,...
We examined the influence of lifestyle on brain aging after nearly 30 years, and tested the hypothesis that young adult general cognitive ability (GCA) would moderate these effects. In the community-dwelling Vietnam Era Twin Study of Aging (VETSA), 431 largely non-Hispanic white men completed a test of GCA at mean age 20. We created a modifiable li...
Background:
Although not strongly correlated with current objective cognitive ability, subjective cognitive decline (SCD) is a risk factor for Alzheimer's disease. Most studies focus on SCD in relation to future decline rather than objective prior decline that it purportedly measures.
Objective:
We evaluated whether self-report of cognitive decl...
Neuroimaging signatures based on composite scores of cortical thickness and hippocampal volume predict progression from mild cognitive impairment to Alzheimer’s disease. However, little is known about the ability of these signatures among cognitively normal adults to predict progression to mild cognitive impairment. Towards that end, a signature se...
Background
Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) are commonly reported co-occurring mental health consequences of psychological trauma exposure. The disorders have high genetic overlap. Trauma is a complex phenotype but research suggests that trauma sensitivity has a heritable basis. We investigated whether sensit...
Objective:
Abnormal white matter (AWM) on magnetic resonance imaging is associated with cognitive performance in older adults. We explored cognitive associations with AWM during late-midlife.
Method:
Participants were community-dwelling men (n = 242; M = 61.90 years; range = 56-66). Linear-mixed effects regression models examined associations of t...
Introduction:
The locus coeruleus (LC) undergoes extensive neurodegeneration in early Alzheimer's disease (AD). The LC is implicated in regulating the sleep-wake cycle, modulating cognitive function, and AD progression.
Methods:
Participants were 481 men (ages 62 to 71.7) from the Vietnam Era Twin Study of Aging. LC structural integrity was inde...
Background
Clarifying the relationship between depression symptoms and cardiometabolic and related health could clarify risk factors and treatment targets. The objective of this study was to assess whether depression symptoms in midlife are associated with the subsequent onset of cardiometabolic health problems.
Methods
The study sample comprised...
Background:
Understanding metabolic mechanisms associated with cognitive changes preceding an Alzheimer's disease (AD) diagnosis could advance our understanding of AD progression and inform preventive methods.
Objective:
We investigated the metabolomics of the early changes in executive function and delayed recall, the earliest aspects of cognit...
Background
Alzheimer’s disease (AD) brain signatures based on cortical thickness, with or without hippocampal volume, predict progression from mild cognitive impairment (MCI) to AD. It would be advantageous if AD signatures could predict earlier progression to MCI. Toward that end, a signature sensitive to microstructural changes that may predate m...
Background
Longitudinal studies of aging are central to identifying early predictors of and mechanisms underlying late‐life cognitive decline and dementia. However, these studies typically lack cognitive data from earlier ages. It is therefore unclear how peak young adult general cognitive ability (GCA) and maintenance of GCA from young adulthood i...
Background
Recent studies have reported significant associations between modifiable lifestyle factors and dementia (Licher et al, 2019; Lourida et al, 2019). We sought to extend those findings by examining whether the effect of lifestyle on brain age, a possible risk factor for dementia, is moderated by one’s level of general cognitive ability (GCA...
Background
The locus coeruleus (LC) is one of the earliest sites of Alzheimer’s disease (AD) pathology, and it experiences extensive neurodegeneration through the disease course. The LC has long been associated with arousal and the sleep‐wake cycle, which are commonly disrupted in AD. Recent research implicates the LC in modulating cognitive functi...
Background
Practice effects (PEs) mask true cognitive decline. Even with declines at follow‐up, PEs can still obscure even steeper declines. Accounting for PEs means that impairment cutoffs are reached earlier. Importantly, mild cognitive impairment (MCI) would be detected earlier. If these diagnoses are valid, there should be more biomarker‐positi...
Alzheimer's dementia (AD) begins many years before its clinical symptoms. Metabolic dysfunction represents a core feature of AD and cognitive impairment, but few metabolomic studies have focused on cognitive aging in midlife. Using an untargeted metabolomics approach, we identified metabolic predictors of cognitive aging in midlife using fasting pl...
Objective
Practice effects on cognitive tests obscure decline, thereby delaying detection of mild cognitive impairment (MCI). This reduces opportunities for slowing Alzheimer’s disease progression and can hinder clinical trials. Using a novel method, we assessed the ability of practice-effect-adjusted diagnoses to detect MCI earlier, and tested the...
Importance
Both cognitive reserve and modifiable lifestyle behaviors are associated with dementia risk. The effect of early lifestyle behaviors and cognitive reserve on late midlife brain aging could inform early identification and risk reduction of future dementia.
Objective
Determine associations of young adult cognitive reserve, early midlife l...