Harriet Demnitz-King

• University College London

BACKGROUND Digital biomarkers are gaining interest as proxy markers for mental health as they enable passive and continuous data collection. However, the association between digital biomarkers of health and anxiety, both generalised anxiety disorder and anxiety symptoms, remains unknown. OBJECTIVE This systematic review and meta-analysis aimed to...

Question: What is the current evidence base for the association between digital biomarkers from wrist-worn wearables, loneliness and social isolation in adults? Study selection and analysis: We systematically searched six databases from inception to 24th September, 2024. We narratively synthesised findings and pooled effect sizes using random-effec...

Background Despite evidence that sex can modulate Alzheimer’s disease (AD) risk, whether risk factors are similarly related to AD markers in women and men remains largely unexplored. We aimed to assess how a combination of potentially modifiable risk factors are associated with cognitive and pathological markers of AD in older women and men. Metho...

Background Anxiety, both generalised anxiety disorder and anxiety symptoms, has been recognised as a risk factor and prodromal symptom of dementia. Digital biomarkers are gaining interest as proxy markers for mental health because they enable passive and continuous data collection, allowing for early detection. However, the association between digi...

Background Despite evidence that sex can modulate Alzheimer’s disease (AD) risk, whether risk factors are similarly related to AD markers in women and men remains largely unexplored. We aimed to assess how a combination of potentially modifiable risk factors are associated with cognitive and pathological markers of AD in older women and men. Metho...

Background Psychological factors such as repetitive negative thinking, proneness to experience distress, and perceived stress are associated with increased risk of neurodegeneration and clinical dementia, whereas having a sense of life‐purpose, self‐reflection, and dispositional mindfulness may be protective. However, whether combinations of these...

Psychological characteristics are associated with varying dementia risk and protective factors. To determine whether these characteristics aggregate into psychological profiles and whether these profiles differentially relate to aging health, we conducted a cross-sectional investigation in two independent middle-aged (51.4 ± 7.0 years (mean ± s.d.)...

Background Increased stress is a proposed risk factor for Alzheimer’s disease (AD). We examined cross-sectional associations between circulating stress biomarkers and multimodal measures of brain health and cognition susceptible to AD in older adults and sex-specific subgroups. Methods Baseline data from 132 cognitively unimpaired participants wit...

Meditation is a mental training approach that can improve mental health and well-being in aging. Yet the underlying mechanisms remain unknown. The Medit-Ageing model stipulates that three mechanisms — attentional, constructive, and deconstructive — upregulate positive psycho-affective factors and downregulate negative ones. To test this hypothesis,...

Background Cardiovascular risk factors represent an important health issue in older adults. Previous findings suggest that meditation training could have a positive impact on these risk factors. The objective of this study was to investigate the effects of an 18-month meditation-based intervention on cardiovascular health. Methods Age-Well was a r...

Emerging evidence suggests that repetitive negative thinking (RNT; i.e., worry and ruminative brooding) is associated with biomarkers of Alzheimer’s disease. Given that women have a greater risk of many neurodegenerative diseases, this study investigated whether worry and brooding are associated with general neurodegeneration and whether associatio...

Understanding the factors that predict why some individuals perceive to respond more to meditation training than others could impact the development, efficacy, adherence levels, and implementation of meditation-based interventions. We investigated individual-level variables associated with self- and teacher-perceived responsiveness to longer-term m...

The COVID-19 pandemic negatively affected known dementia risk factors and cognition in older adults. We invited adults with mild cognitive concerns without dementia, aged ≥60 years participating in a randomised controlled trial of a psychosocial, secondary dementia prevention intervention, to complete a co-designed, semi-structured qualitative surv...

Aging is associated with cognitive changes, even in the absence of brain pathology. This study aimed to determine if meditation training, by comparison to active and passive control groups, is linked to changes in the perception of cognitive functioning in older adults. One hundred thirty-four healthy older participants from the Age-Well Randomized...

Introduction Mental health conditions are associated with cognition and physical function in older adults. We examined whether worry and ruminative brooding, key symptoms of certain mental health conditions, are related to subjective and/or objective measures of cognitive and physical (cardiovascular) health. Methods We used baseline data from 282...

Emerging evidence suggests that Repetitive Negative Thinking (RNT; i.e., worry and ruminative brooding) is associated with biomarkers of Alzheimer’s disease. However, it is neither known whether RNT may be a marker of neurodegenerative disease more generally, nor the mechanism through which RNT may act. Given that women have greater risk of many ne...

Objective Poor sleep and high levels of repetitive negative thinking (RNT), including future-directed (ie, worry) and past-directed (ie, brooding) negative thoughts, have been associated with markers of dementia risk. The relationship between RNT and sleep health in older adults is unknown. This study aimed to investigate this association and its s...

Background Recent evidence in Alzheimer’s diseases suggests that early dysfunction of emotional processing may precede the onset of cognitive decline and dementia. Altered functional brain connectivity patterns also occur along with other brain changes many years before clinical AD symptoms. Method We combined baseline multimodal neuroimaging data...

Background Age is the strongest risk factor for dementia, including Alzheimer’s disease (AD). However, across individuals of the same chronological age there is considerable heterogeneity in rates of cognitive decline. These differences have been attributed to individual differences in age‐related biological processes, including brain protein expre...

Background Repetitive Negative Thinking (RNT) includes negative thoughts about the future (worry) and past (ruminative brooding). RNT has been associated with Alzheimer’s disease (AD) pathology (Marchant et al. Alzheimers Dement . 2020;16(7)) and different patterns of functional connectivity of the triple network of attention, namely, the default m...

Background Positive and negative psychological factors represent pertinent moderators of relative risk and protection for cognitive decline and dementia. For example, repetitive negative thinking has been associated with accelerated cognitive decline and AD pathology ¹ , whereas self‐reflection and purpose in life have been related to better cognit...

Background Non‐pharmacological interventions are a potential strategy to maintain or promote cognitive functioning in older adults. We investigated the effects of 18‐months meditation or non‐native language training versus no intervention on cognition in older adults. Method Age‐Well was an observer‐blind, randomised, controlled clinical trial wit...

Background Anxiety has been identified as both a risk factor and prodromal symptom for Alzheimer’s disease (AD) and related dementias, however, the underlying neurobiological correlates remain unknown. The aim of this systematic review and meta‐analysis was to examine the association between anxiety symptoms and two defining markers of AD neuropath...

Objectives Older adults with subjective cognitive decline (SCD) recruited from memory clinics have an increased risk of developing dementia and regularly experience reduced psychological well-being related to memory concerns and fear of dementia. Research on improving well-being in SCD is limited and lacks non-pharmacological approaches. We investi...

INTRODUCTION: APOE4 genotype and lifestyle have been associated with Alzheimer's disease (AD) risk, but how they interact on neuroimaging and cognitive markers of aging and AD remains unclear. METHODS: In 135 cognitively unimpaired older adults from the baseline Age-Well trial, we investigated the interaction between APOE4 status and cognitive acti...

Importance: Nonpharmacological interventions are a potential strategy to maintain or promote cognitive functioning in older adults. Objective: To investigate the effects of 18 months' meditation training and 18 months' non-native language training on cognition in older adults. Design, setting, and participants: This study was a secondary analy...

Persistent fatigue constitutes a prevalent and debilitating symptom in several diseases. The symptom is not effectively alleviated by pharmaceutical treatments, and meditation has been proposed as a non-pharmacological intervention. Indeed, meditation has been shown to reduce inflammatory/immune problems, pain, stress, anxiety and depression which...

Background APOE4 is the main genetic risk factor for Alzheimer’s disease (AD). Recent findings suggest that lifestyle factors could modulate the association between APOE4 and cognitive impairment and/or dementia risk. However, a comprehensive assessment of the interactions between lifestyle and APOE4 status on neuroimaging and cognitive markers of...

Objective: Anxiety has been identified as both a risk factor and prodromal symptom for Alzheimer's disease (AD) and related dementias, however, the underlying neurobiological correlates remain unknown. The aim of this systematic review and meta-analysis was to examine the association between anxiety symptoms and two defining markers of AD neuropat...

Objectives Aging people experience a slight decrease in their cognitive efficiency, even in the absence of brain pathology. Concurrently, several studies have reported positive effects of meditation practice on older adults’ cognitive functioning. This study aimed to assess if dispositional mindfulness (or more generally trait meditation capacities...

Objectives Older adults with subjective cognitive decline (SCD) recruited from memory clinics have an increased risk of developing dementia and regularly experience reduced psychological well-being related to memory concerns and fear of dementia. Research on improving well-being in SCD is limited and lacks non-pharmacological approaches. We investi...

Background Older individuals with subjective cognitive decline (SCD) perceive that their cognition has declined but do not show objective impairment on neuropsychological tests. Individuals with SCD are at elevated risk of objective cognitive decline and incident dementia. Non-pharmacological interventions (including mindfulness-based and health se...

Mindfulness-based programs (MBPs) are increasingly utilized to improve mental health. Interest in the putative effects of MBPs on cognitive function is also growing. This is the first meta-analysis of objective cognitive outcomes across multiple domains from randomized MBP studies of adults. Seven databases were systematically searched to January 2...

Background and Objectives Self-reflection (the active evaluation of ones thoughts, feelings and behaviours) can confer protection against adverse health outcomes. Its impact on markers sensitive to Alzheimer’s disease (AD), however, is unknown. The primary objective of this cross-sectional study was to examine the association between self-reflectio...

The primary aim of this study was to investigate the relationship between meditation experience and repetitive negative thinking (RNT) in regular meditators with a wide range of experience, and to examine the extent to which self-compassion and mindfulness mediate this relationship. RNT is a transdiagnostic process that is implicated in the develop...

Objectives Deepening our understanding of the mechanisms by which meditation practices impact well-being and human flourishing is essential for advancing the science of meditation. A recent phenomenologically grounded classification system distinguishes attentional, constructive, and deconstructive forms of meditation based on the psychological mec...

Background Subjective cognitive decline (SCD) denotes self‐reported cognitive concerns in the absence of objective cognitive impairment. Individuals with SCD convert to dementia at twice the annual rate of healthy controls, with relatively poorer cognition in SCD conferring additional risk. Non‐pharmacological interventions are currently undergoing...

Background Self‐reflection is conceptualised as an introspective process that involves active evaluation of one’s thoughts, feelings and behaviours. Engagement in self‐reflection is thought to yield more adaptive stress responses, that in turn result in better short‐term (e.g., reduced inflammatory responses to stressors) and long‐term (e.g., recov...

Background: The Lifetime of Experiences Questionnaire (LEQ) assesses complex mental activity across the life-course and has been associated with brain and cognitive health. The different education systems and occupation classifications across countries represent a challenge for international comparisons. The objectives of this study were four-fold:...

Repetitive negative thinking (RNT) is a cognitive process characterised by intrusive, repetitive, and difficult-to-disengage-from negative thoughts. Heightened RNT levels are prevalent across clinical disorders and have been associated with ill-health (e.g. cardiovascular disease), even at lower, non-clinical levels. Identifying the neuroanatomical...

Introduction: Older adults experiencing subjective cognitive decline (SCD) have a heightened risk of developing dementia and frequently experience subclinical anxiety, which is itself associated with dementia risk. Objective: To understand whether subclinical anxiety symptoms in SCD can be reduced through behavioral interventions. Methods: SCD...

Background Subjectively experienced cognitive decline (SCD), particularly when accompanied by worries, has been associated with an increased risk for dementia. Repetitive negative thinking (RNT) is a transdiagnostic process that manifests across several mental health disorders previously associated with increased vulnerability to dementia. RNT has...

Background Subjectively experienced cognitive decline (SCD), particularly associated with worries, in older adults is known to be a risk factor for dementia. So far, only few studies focus on gender‐specific profiles in SCD. Method Gender differences in SCD subjects who were enrolled in the SCD‐Well trial were analyzed with regard to their percept...

Background Reflective pondering is an introspective mechanism conceptualised as actively seeking a solution to one’s problems. Literature has consistently demonstrated positive associations between reflective pondering and improved mental health outcomes in clinical populations. Given that poor mental health (e.g. depression, anxiety) has been asso...

Background The Lifetime of Experiences questionnaire (LEQ, Valenzuela and Sachdev, 2007) is an instrument that comprehensively assesses mental activity (education/occupation and leisure activities) across the lifespan (13‐30, 30‐65, 65‐present). The LEQ has been associated with brain health outcomes and cognitive decline. Challenges for the use of...

Background The primary focus of mindfulness‐based program (MBP) research to date has been on mental health. More recently, attention has turned to putative effects on cognition. An evidence synthesis is required to answer the key question of ‘Do MBPs confer cognitive benefit, and if so, for whom?’ A particularly crucial distinction is whether benef...

Background In the absence of a cure or effective treatment for dementia, attention has shifted towards identifying risk factors for prevention. Subjective Cognitive Decline (SCD) describes self-perceived worsening of cognition despite unimpaired performance on neuropsychological tests. SCD has been associated with an increased dementia risk and ste...

Background In the absence of a cure or effective treatment for dementia, attention has shifted towards identifying risk factors for prevention. Subjective Cognitive Decline (SCD) describes self-perceived worsening of cognition despite unimpaired performance on neuropsychological tests. SCD has been associated with an increased dementia risk and ste...

Background: In the absence of a cure or effective treatment for dementia, attention has shifted towards identifying risk factors for prevention. Subjective Cognitive Decline (SCD) describes self-perceived worsening of cognition despite unimpaired performance on neuropsychological tests. SCD has been associated with an increased dementia risk and st...

Visuo-spatial context and emotional valence are powerful cues to episodic retrieval, but the contribution of these inputs to semantic cognition has not been widely investigated. We examined the impact of visuo-spatial, facial emotion and prosody cues and miscues on the retrieval of dominant and subordinate meanings of ambiguous words. Cue photograp...

Introduction Subjectively experienced cognitive decline in older adults is an indicator of increased risk for dementia and is also associated with increased levels of anxiety symptoms. As anxiety is itself emerging as a risk factor for cognitive decline and dementia, the primary question of the present study is whether an 8-week mindfulness-based i...