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Publications (380)
Ketamine has received considerable attention for its rapid and robust antidepressant response over the past decade. Current evidence, in clinical populations, predominantly relates to parenterally administered ketamine, which is reported to produce significant undesirable side effects, with additional concerns regarding long-term safety and abuse p...
Background
Existing treatments for young people with severe depression have limited effectiveness. The aim of the Study of Ketamine for Youth Depression (SKY-D) trial is to determine whether a 4-week course of low-dose subcutaneous ketamine is an effective adjunct to treatment-as-usual in young people with major depressive disorder (MDD).
Methods...
Various methods have been developed to combine inference across multiple sets of results for unsupervised clustering, within the ensemble clustering literature. The approach of reporting results from one 'best' model out of several candidate clustering models generally ignores the uncertainty that arises from model selection, and results in inferen...
Background: Existing treatments for young people with severe depression have limited effectiveness. The aim of the Study of Ketamine for Youth Depression (SKY-D) trial is to determine whether a 4-week course of low-dose subcutaneous ketamine is an effective adjunct to treatment-as-usual in young people with major depressive disorder (MDD).
Methods:...
Suicidality is a prevalent mental health condition, and managing suicidal patients is one of the most challenging tasks for healthcare professionals due to the lack of rapid-acting, effective psychopharmacological treatment options. According to the literature, suicide has neurobiological underpinnings that are not fully understood, and current tre...
Dementia is understood to arise from a mixed etiology, enveloping chronic inflammatory and vascular impacts on the brain, driven by a constellation of modifiable risk factors which are largely mediated by lifestyle-related behaviors. These risk factors manifest over a prolonged preclinical period and account for up to 40% of the population attribut...
Neurodevelopment during early childhood and adolescence are recognised as critical periods, with potential life-long lasting impacts on mental health and wellbeing. The time-frame of these neurodevelopmental changes also correspond to one in five individuals aged 9–17 years old being diagnosed with a mental health condition. Furthermore, sex-based...
The dysregulation of excitatory and inhibitory neurotransmission is considered a pathological marker of Anorexia Nervosa (AN), however, no systematic evaluation of the proton Magnetic Resonance Spectroscopy (1H-MRS) literature has been conducted to date. Accordingly, we conducted a systematic review of neurometabolite differences between individual...
Cyberbullying is an increasingly problematic psychosocial health risk, particularly in youth. Electroencephalography (EEG) is commonly utilized to investigate the potential effects of social behaviors on brain activity. Hence, the current paper provides a systematic review of EEG-related studies that have addressed cyberbullying-like behaviors. Ini...
The brain is the most complex organ in the human body, making it susceptible to many abnormalities [...]
Cross-frequency coupling between the phase of slower oscillatory activity and the amplitude of faster oscillatory activity in the brain (phase-amplitude coupling; PAC), is a promising new biological marker for mental health. Prior research has demonstrated that PAC is associated with mental health. However, most research has focused on within-regio...
Fatigue is a long-lasting problem in traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD), with limited research that investigated the fatigue-related white-matter changes within TBI and/or PTSD cohorts. This exploratory cross-sectional study used diffusion tensor imaging (DTI) and neuropsychological data collected from 153 male V...
Anorexia nervosa (AN) is a severe illness with diverse aetiological and maintaining contributors including neurobiological, metabolic, psychological, and social determining factors. In addition to nutritional recovery, multiple psychological and pharmacological therapies and brain-based stimulations have been explored; however, existing treatments...
Patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often report disrupted and unrefreshing sleep in association with worsened fatigue symptoms. However, the nature and magnitude of sleep architecture alteration in ME/CFS is not known, with studies using objective sleep measures in ME/CFS generating contradictory results. The...
Background:
Ketamine has recently been proposed as a treatment option for suicidality. Whilst its mechanism of action has been explored at molecular levels, the effect on the brain at the organ level remains unclear. Here we investigate immediate post-treatment and prolonged large-scale resting-state neural network changes to elucidate the neurona...
Background:
Ketamine has considerable therapeutic potential in alleviating major depressive disorder (MDD) and chronic suicidality. However, the clinical diagnosis of neuropsychiatric disorders requires more robust diagnostic criteria. Electroencephalography (EEG) has shown promise in classifying depressive and suicidal patients from healthy indiv...
Normative modeling is a statistical approach to quantify the degree to which a particular individual-level measure deviates from the pattern observed in a normative reference population. When applied to human brain morphometric measures it has the potential to inform about the significance of normative deviations for health and disease. Normative m...
Anorexia nervosa is a disorder associated with serious adverse health outcomes, for which there is currently considerable treatment ineffectiveness. Characterised by restrictive eating behaviours, distorted body image perceptions and excessive physical activity, there is growing recognition anorexia nervosa is associated with underlying dysfunction...
Cyberbullying is recognized as a problematic behavior that is often first identified during adolescence, a period which has increased susceptibility to developing mental health disorders. Due to the ever-growing nature of social media and technology, cyberbullying behaviors are becoming increasingly problematic for the adolescent demographic. Resea...
Numerous studies have demonstrated that low‐dose subanesthetic intravenous ketamine infusion treatment leads to rapid improvement of treatment‐resistant depression. The following case report describes the use of a very low‐dose subcutaneous ketamine as a form of maintenance in a patient with severe treatment‐resistant depression using a retrospecti...
The experience of stress is often utilised in models of emerging mental illness and neurobiological systems are implicated as the intermediary link between the experience of psychological stress and the development of a mental disorder. Chronic stress and prolonged glucocorticoid exposure have potent effects on neuronal architecture particularly in...
Adolescence is a critical period of social and neural development. Brain regions which process social information develop throughout adolescence as young people learn to navigate social environments. Studies investigating brain structural connectivity (indexed by white matter (WM) integrity), and social connectedness in adolescents have been limite...
Oral ketamine has shown to be a rapid-acting antidepressant and a potential treatment option for suicidality, however, repeated doses are often required. Objective markers of prolonged treatment response are needed to help individuals and clinicians make informed treatment decisions. This secondary analysis sought to identify objective electrophysi...
Background
Although the primary aetiology of Eating Disorders (ED) remains unknown, research suggests a complex interplay of biological, psychological, and cultural/environmental factors. This paper aims to systematically review the literature on neuroimaging studies that measure socio-cognitive factors, in the context of body dissatisfaction and E...
Delineating neurobiological markers of youth mental health is crucial for early identification and treatment. One promising marker is phase-amplitude coupling (PAC), cross-frequency coupling between the phase of slower oscillatory activity and the amplitude of faster oscillatory activity in the brain. Prior research has demonstrated that PAC is ass...
Various methods have been developed to combine inference across multiple sets of results for unsupervised clustering, within the ensemble and consensus clustering literature. The approach of reporting results from one `best' model out of several candidate clustering models generally ignores the uncertainty that arises from model selection, and resu...
The role of gender and the associated brain activation when witnessing cyberbullying requires investigation. The current study aimed to determine whether brain responses to cyberbullying differ according to gender and level of wellbeing. We hypothesised that females and males would activate different regions of the brain when witnessing cyberbullyi...
Introduction:
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), is a debilitating illness affecting up to 24 million people worldwide but concerningly there is no known mechanism for ME/CFS and no objective test for diagnosis. A series of our neuroimaging findings in ME/CFS, including functional MRI (fMRI) signal characteristics and str...
We provided the dataset of brain connectome matrices, their similarities measures to self and others longitudinally, and Kessler's psychological distress scales (K10) including the response to each question. The dataset can be used to replicate the results of the manuscript titled “A longitudinal study of functional connectome uniqueness and its as...
The so-called “psychedelic renaissance” has stimulated expanded interest in several classes of drugs that appear to possess transdiagnostic effects in the treatment of mental health disorders, specifically. N-methyl-d-aspartate receptor (NMDAR) antagonists are one such class with diverse therapeutic potential. NMDARs mediate excitatory postsynaptic...
Introduction
To better understand the relationships between neurophysiology, cognitive function and psychopathology risk in adolescence there is value in identifying data-driven subgroups based on measurements of brain activity and function, and then comparing cognition and mental health between such subgroups.
Methods
We developed a flexible and...
Objective: The objective of this scoping review is to explore current knowledge on the genetic regulation implicated with post-traumatic stress disorder (PTSD). Thereby identifying the dysregulated expression of epigenetic and post-transcriptional biomarkers that contribute to molecular perturbations seen in PTSD and their diagnostic, prognostic an...
Each human brain has a unique functional synchronisation pattern (functional connectome) analogous to a fingerprint that underpins brain functions and related behaviours. Here we examine functional connectome (whole-brain and 13 networks) maturation by measuring its uniqueness in adolescents who underwent brain scans longitudinally from 12 years of...
Aims:
Depression and bipolar disorder patients have previously been shown to have impaired white matter (WM) integrity compared to healthy controls. This study aimed to investigate potential sex differences that may provide further insight into the pathophysiology of these highly debilitating mood disorders.
Methods:
Participants (17-30 years of...
Adolescence is a period of significant brain development and decreased sleep quality, making it an ideal period to investigate potential early indicators of anxiety disorders such as psychological distress. The amygdala and hippocampus have been implicated in the neurobiology of anxiety symptoms. Sex-based differences in anxiety symptoms and sleep...
Social connectedness is well established as an important aspect of adolescence, with higher levels typically resulting in positive mental health and well-being. Cyberbullying is a prevalent concern during adolescence and is a significant contributor to poor mental health outcomes during this important phase of life. Research shows that social conne...
Background
Developmental stuttering is thought to be underpinned by structural impairments in the brain. The only way to support the claim that these are causal is to determine if they are present before onset.
Materials and Methods
Magnetic resonance imaging (MRI) was conducted on 18 neonates, aged 8–18 weeks, 6 of whom were determined to be gene...
Background
Stress is prevalent in people experiencing suicidality and is a major contributor to the development of mental disorders. Evidence suggests ketamine shows capacity to reverse stress-induced brain changes. Though stress and ketamine have been explored individually for suicidality, this study is the first to examine ketamine treatment for...
Cyberbullying contributes to poor mental health outcomes and quality of life (QoL), and peer victimisation has been shown to be positively associated with both positive and negative metacognition. Whilst metacognitive beliefs are associated with pathological worry, obsessive–compulsive symptoms, and rumination in depression, research is yet to exam...
Background: Mindfulness training has been associated with improved attention and affect regulation in preadolescent children with anxiety related attention impairments, however little is known about the underlying neurobiology. This study sought to investigate the impact of mindfulness training on functional connectivity of attention and limbic bra...
It has been suggested that biological markers that define mental health are different to those that define mental illness. The basal ganglia changes dramatically over adolescence and has been linked to wellbeing and mental health disorders in young people. However, there remains a paucity of research on wellbeing and brain structure in early adoles...
Major depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in adult MDD patients, and whether this process is associated with clinical characteristics in a large multicenter international dataset. We performed a mega-analysis by pooling bra...
Emerging evidence suggests that obesity impacts brain physiology at multiple levels. Here we aimed to clarify the relationship between obesity and brain structure using structural MRI (n = 6420) and genetic data (n = 3907) from the ENIGMA Major Depressive Disorder (MDD) working group. Obesity (BMI > 30) was significantly associated with cortical an...
Recovery of functioning is integral to successful treatment outcomes in depressive illness. Optimal antidepressant treatment results in both symptomatic remission and functional recovery. Oral ketamine rapidly reduces suicidality and depression; however, reports of functional and wellbeing outcomes are lacking. This study examines participants' soc...
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,...
Suicidal thoughts and behaviors (STB) are a leading cause of death in adolescence. To date, most research with youth has focused on risk factors for suicide; and less attention has been paid to resilience factors. This study examined whether positive beliefs and social connectedness moderate associations between mental health symptoms and STB. A co...
Introduction
COVID-19 has resulted in major life changes to the majority of the world population, particularly adolescents, with social-distancing measures such as home-based schooling likely to impact sleep quality. Increased worry is also likely considering the substantial financial, educational and health concerns accompanying COVID-19. White ma...
Chronic suicidality has been associated with neuronal atrophy in cortico-striato-limbic regions and is thought to be mediated via a glutamatergic imbalance. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been posited to exert anti-suicidal effects by promoting neurogenesis via modulation of glutamatergic transmission. This voxel-...
Background
The pervasiveness of subclinical anxiety in children, highlights the need to identify its neurobiological underpinnings to better inform interventions. Given the now well-established link between aberrant emotion processing and anxiety disorders and yet limited neurobiologically-informed research in this area, this study examined the neu...
Adolescence is a period of significant anatomical and functional brain changes, and complex interactions occur between mental health risk factors. The Longitudinal Adolescent Brain Study commenced in 2018, to monitor environmental and psychosocial factors influencing mental health in 500 adolescents, for 5 years. Participants are recruited at age 1...
Identifying biomarkers of developing mental disorder is crucial to improving early identification and treatment—a key strategy for reducing the burden of mental disorders. Cross-frequency coupling between two different frequencies of neural oscillations is one such promising measure, believed to reflect synchronization between local and global netw...
Objective
Neuroimaging studies of suicidal behavior have so far been conducted in small samples, prone to biases and false-positive associations, yielding inconsistent results. The ENIGMA-MDD working group aims to address the issues of poor replicability and comparability by coordinating harmonized analyses across neuroimaging studies of major depr...
Objective:
The majority of individuals experiencing depression or in crisis do not seek assistance through formal support pathways. Thus, the presence of informal “gatekeepers” in the community is vital to identifying and supporting these individuals through crisis. The objective of this study was to evaluate the longitudinal effectiveness of “Saf...
Recently, low-dose ketamine has been proposed as a rapid-acting treatment option for suicidality. The majority of studies to date have utilised intravenous (IV) ketamine, however, this route of administration has limitations. On the other hand, oral ketamine can be administered in a range of settings, which is important in treating suicidality, alt...
The present study investigated differences in white matter (WM) integrity between 96 young people with affective and/or psychotic symptoms classified at an early stage of mental disorder (i.e. ‘attenuated syndrome’; stage 1b), 85 young people classified at a more advanced stage of mental disorder (i.e. ‘discrete disorder’; stage 2), and 81 demograp...
In a series of cognitive and neuroimaging studies we investigated the relationships between adolescent sleep quality, white matter (WM) microstructural integrity and psychological distress. Collectively these studies showed that during early adolescence (12 – 14 years of age), sleep quality and psychological distress are significantly related. Slee...
Objective:
This study aimed to investigate the relationship between obesity and oxidative stress in older adults at risk for dementia. It also aimed to explore the influence of physical activity on the relationship between obesity and oxidative stress in this at risk cohort.
Methods:
Older adults at risk for dementia underwent comprehensive medi...
It has been difficult to find robust brain structural correlates of the overall severity of major depressive disorder (MDD). We hypothesized that specific symptoms may better reveal correlates and investigated this for the severity of insomnia, both a key symptom and a modifiable major risk factor of MDD. Cortical thickness, surface area and subcor...
Mindfulness has been shown to improve attentional performance, which is known to decline in aging. Long-latency electroencephalographic (EEG) event-related potential (ERP) changes have been reported immediately after mindfulness training, however the enduring stability of these effects is unknown. Furthermore, the ability of mindfulness to impact e...
Background
Developmental studies have shown adolescence is a period of ongoing white matter (WM) development, reduced sleep quality and the onset of many mental disorders. Findings indicate the WM development of the uncinate fasciculus (UF), a WM tract suggested to play a key role in mental disorders, continues throughout adolescence. While these s...
Background
Adolescence is an important period for developing one’s sense of self. Social connectedness has been linked to a sense of self which in turn has links to resilience in mental disorders. Adolescence is also a period of increased risk of chronic sleep deprivation during a time of ongoing white matter (WM) maturation. The complex relationsh...
Background: Although numerous studies have reported an association between sleep quality and mental health, few have focused on this association exclusively in early adolescence. Targeting this age group is vital as many mental illnesses first emerge during adolescence and remain a significant burden throughout life.
Method: In the current study n...
The prevailing evidence suggests that patients with severe COVID-19 seem to have an overreaction of the immune
system demonstrating exacerbated levels of inflammation caused by a “cytokine storm.” At this early stage, the
mechanisms underpinning COVID-19 are still subject to intense scrutiny and the long-term mental health consequences
as a result...
Background
The glutamatergic modulator ketamine has been shown to result in rapid reductions in both suicidal ideation (SI) and depressive symptoms in clinical trials. There is a practical need for identification of pre-treatment predictors of ketamine response. Previous studies indicate links between treatment response and body mass index (BMI), d...
For many traits, males show greater variability than females, with possible implications for understanding sex differences in health and disease. Here, the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Consortium presents the largest-ever mega-analysis of sex differences in variability of brain structure, based on international da...
Age-related cognitive decline Transcranial Doppler Middle cerebral artery blood flow velocity (MCAv) Auditory oddball Event-related potentials a b s t r a c t The aim of this study was to determine the effect of age on the relationship between cerebrovascular function and the neural bases of sustained attention. Twenty-seven healthy young adults (a...
Background:
Since the 1990s, neuroimaging has been utilised to study Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a debilitating illness with unknown aetiology. While brain abnormalities in ME/CFS have been identified, relatively little is known regarding which specific abnormalities are consistently observed across research groups...
Introduction
Poor sleep quality has been linked to reduced neural connectivity through decreased white matter (WM) structural integrity. WM tract development has been shown to continue throughout adolescence with studies reporting positive correlations between diffusion-derived estimates of structural integrity and reduced sleep quality in adult sa...
Alterations in white matter (WM) microstructure have been implicated in the pathophysiology of major depressive disorder (MDD). However, previous findings have been inconsistent, partially due to low statistical power and the heterogeneity of depression. In the largest multi-site study to date, we examined WM anisotropy and diffusivity in 1305 MDD...
Whilst it is well documented that cyberbullying is linked to poor mental health outcomes, limited research has examined how cyberbullying may influence brain development adolescents, and the influence of each of these factors. The paper’s primary objective was to develop an understanding of research to date that addresses any relationship between a...
ObjectivesA core process trained during mindfulness is inhibitory control. A decline in inhibitory control is thought to underlie age-related cognitive declines. Electroencephalographic event-related potentials (ERPs) index both the speed and allocation of attentional resources, making them useful in assessing cognition in ageing. While mindfulness...
Major depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in adult MDD patients, and whether this process is associated with clinical characteristics in a large multicenter international dataset. We performed a mega-analysis by pooling bra...
