Paul Fitzgerald

Paul Fitzgerald
Monash University (Australia) · Monash Alfred Psychiatry Research Centre

MBBS, MPM, PhD

About

640
Publications
162,527
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29,051
Citations
Additional affiliations
June 2001 - present
Monash University (Australia)
Position
  • Professor of Psychiatry, Deputy Director

Publications

Publications (640)
Preprint
Full-text available
We investigated the effects of transcranial alternating current stimulation (tACS) targeted to the bilateral medial prefrontal cortex (mPFC) and administered at either delta or alpha frequencies, on brain activity and apathy in people with Huntingtons disease (HD) (n = 17). Neurotypical controls (n = 20) were also recruited for comparison. All part...
Preprint
Objective To find sensitive biological markers of non-motor symptoms in Huntington’s disease (HD), which are essential for the development and assessment of novel treatments. Methods We used resting state EEG to examine differences in oscillatory activity (analysing the isolated periodic as well as the complete EEG signal) and functional connectiv...
Preprint
Objectives Mindfulness meditation is associated with better attention function. Performance monitoring and error-processing are important aspects of attention. We investigated whether experienced meditators showed different neural activity related to performance monitoring and error-processing. Previous research has produced inconsistent results. T...
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Prolonging survival in good health is a fundamental societal goal. However, the leading determinants of disability-free survival in healthy older people have not been well established. Data from ASPREE, a bi-national placebo-controlled trial of aspirin with 4.7 years median follow-up, was analysed. At enrolment, participants were healthy and withou...
Preprint
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Electroencephalography (EEG) is commonly used to examine neural activity time-locked to the presentation of a stimulus, referred to as an Event-Related Potential (ERP). However, EEG is also influenced by non-neural artifacts, which can confound ERP comparisons. Artifact cleaning can reduce artifacts, but often requires time-consuming manual decisio...
Preprint
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Electroencephalographic (EEG) data is typically contaminated with non-neural artifacts which can confound the results of experiments. Artifact cleaning approaches are available, but often require time-consuming manual input and significant expertise. Advancements in artifact cleaning often only address a single artifact, are only compared against a...
Preprint
Background Cognitive impairment is highly prevalent in schizophrenia and treatment options are severely limited. Development of effective treatments will rely on successful engagement of biological targets. There is growing evidence that the cognitive impairments in schizophrenia are related to impairments in prefrontal cortical inhibition and dysf...
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Although previous research in alcohol dependent populations identified alterations within local structures of the addiction 'reward' circuitry, there is limited research into global features of this network, especially in early recovery. Transcranial magnetic stimulation (TMS) is capable of non-invasively perturbing the brain network while electroe...
Preprint
Alzheimers disease is characterised by progressive cognitive decline for which there are currently no effective treatments. There is growing evidence that neural network dysfunction is a likely proximate cause of cognitive impairment in Alzheimers and, as such, may represent a promising therapeutic target. Here we investigated whether a course of i...
Preprint
Objectives: Up to 40% of adolescents with Major Depressive Disorder (MDD) do not respond to treatment. Repetitive Transcranial Magnetic Stimulation (rTMS) is an effective treatment in adults for MDD which shows promising efficacy in adolescents, however additional controlled investigations are needed. This pilot study compared rTMS applied to the l...
Article
Following on from the publication of the Royal Australian and New Zealand Journal of Psychiatry Mood Disorder Clinical Practice Guidelines (2020) and criticisms of how these aberrantly addressed repetitive transcranial magnetic stimulation treatment of depression, questions have continued to be raised in the journal about this treatment by a small...
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Damage to specific brain circuits can cause specific neuropsychiatric symptoms. Therapeutic stimulation to these same circuits may modulate these symptoms. To determine whether these circuits converge, we studied depression severity after brain lesions (n = 461, five datasets), transcranial magnetic stimulation (n = 151, four datasets) and deep bra...
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Continuous theta burst stimulation (cTBS) is thought to reduce cortical excitability and modulate functional connectivity, possibly by altering cortical inhibition at the site of stimulation. However, most evidence comes from the motor cortex and it remains unclear whether similar effects occur following stimulation over other brain regions. We ass...
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Full-text available
Brain connectivity can be estimated through many analyses applied to electroencephalographic (EEG) data. However, substantial heterogeneity in the implementation of connectivity methods exist. Heterogeneity in conceptualization of connectivity measures, data collection, or data pre-processing may be associated with variability in robustness of meas...
Article
Objective: Electroconvulsive therapy (ECT) is highly effective for treatment-resistant depression (TRD) but may be associated with adverse cognitive effects. Magnetic seizure therapy (MST) is a promising alternative convulsive treatment with a safer cognitive profile. Although there is emerging evidence for the efficacy of MST for TRD as an acute t...
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Late-life depression is common and often inadequately managed using existing therapies. Depression is also associated with increased markers of inflammation, suggesting a potential role for anti-inflammatory agents. ASPREE-D is a sub-study of ASPREE, a large multi-centre, population-based, double-blind, placebo-controlled trial of aspirin vs placeb...
Article
COVER ILLUSTRATION In our paper, we examined and developed the capacity to robustly personalise the spatial targeting of transcranial magnetic stimulation (TMS) for the treatment of depression based on brain connectivity. Optimisation of the dorsolateral prefrontal cortex (DLPFC) stimulation target is based on functional connectivity (FC) with the...
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Background: How “success” is defined in clinical trials of deep brain stimulation (DBS) for refractory psychiatric conditions has come into question. Standard quantitative psychopathology measures are unable to capture all changes experienced by patients and may not reflect subjective beliefs about the benefit derived. The decision to undergo DBS f...
Preprint
Full-text available
Brain connectivity can be estimated through a wide number of analyses applied to electroencephalographic (EEG) data. However, substantial heterogeneity in the implementation of connectivity methods exist. Heterogeneity in conceptualization of connectivity measures, data collection, or data pre-processing may be associated with variability in robust...
Article
Despite more than 25 years of research establishing the antidepressant efficacy of repetitive transcranial magnetic stimulation, there remains uncertainty about the depth and breadth of this evidence base, resulting in confusion as to where repetitive transcranial magnetic stimulation fits in the therapeutic armamentarium in the management of patie...
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Background: Many patients with major depressive disorder (MDD) experience substantial impairment despite the availability of efficacious treatments. We performed a systematic review and meta-analysis to compare antidepressant outcomes in MDD with or without physical or psychiatric comorbidities. Methods: Pubmed, EMBASE, and PsycInfo were searched...
Article
Objectives: Changes in brain connectivity have been observed within the default mode network (DMN) in chronic low back pain (CLBP), however the extent of these disruptions and how they may be related to CLBP requires further examination. While studies using seed-based analysis have found disrupted functional connectivity in the medial prefrontal c...
Article
Cognitive impairment is highly prevalent in schizophrenia and treatment options are severely limited. A greater understanding of the pathophysiology of impaired cognition would have broad implications, including for the development of effective treatments. In the current study we used a multimodal approach to identify neurophysiological markers of...
Article
Objective This study brought together over 60 transcranial magnetic stimulation (TMS) researchers to create the largest known sample of individual participant single and paired-pulse TMS data to date, enabling a more comprehensive evaluation of factors driving response variability. Methods Authors of previously published studies were contacted and...
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Introduction There are no well-established biomedical treatments for the core symptoms of autism spectrum disorder (ASD). A small number of studies suggest that repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, may improve clinical and cognitive outcomes in ASD. We describe here the protocol for a fund...
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Background High-frequency rTMS over the dorsolateral prefrontal cortex (DLPFC) has demonstrated mixed effects on chronic and provoked pain. Objectives/Methods: In this study, a meta-analysis was conducted to characterise the potential analgesic effects of high-frequency rTMS over the DLPFC on both chronic and provoked pain. Results A total of 626...
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Introduction Theta burst pattern repetitive transcranial magnetic stimulation (TBS) is increasingly applied to treat depression. TBS's brevity is well-suited to application in accelerated schedules. Sizeable trials of accelerated TBS are lacking; and optimal TBS parameters such as stimulation intensity are not established. Methods We conducted a t...
Preprint
Full-text available
Continuous theta burst stimulation (cTBS) is thought to reduce cortical excitability and modulate functional connectivity, possibly by altering cortical inhibition at the site of stimulation. However, most evidence comes from the motor cortex and it remains unclear whether similar effects occur following stimulation over other brain regions. We ass...
Preprint
BACKGROUND Many clinical trials investigating treatment efficacy require an interim analysis. Recently we have been running a large multi-site randomized placebo controlled double-blind clinical trial investigating the effect of repetitive transcranial magnetic stimulation (rTMS) treatment for improving or stabilizing the cognition of patients diag...
Article
Background Many clinical trials investigating treatment efficacy require an interim analysis. Recently we have been running a large, multisite, randomized, placebo-controlled, double-blind clinical trial investigating the effect of repetitive transcranial magnetic stimulation (rTMS) treatment for improving or stabilizing the cognition of patients d...
Article
Background Theta Burst stimulation (TBS) is a promising alternative to standard repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant depression (TRD). TBS treatment is delivered over a much shorter time than rTMS, enabling more patients to be treated with the same resources. The aim of this preliminary study was to explore th...
Article
Background Anxiety disorders are highly prevalent and cause substantial personal, social and economic burden. Altered attentional control has been shown to be present across anxiety disorders and is associated with specific changes in brain activity which can be recorded by electroencephalogram (EEG). These include changes in the EEG markers of err...
Article
Objectives: Chronic pain patients often report higher levels of negative emotions, suggesting reduced ability to regulate emotions effectively, however, little is known of the underlying neural cognitive mechanisms. Therefore, the aim of this study was to explore brain activity and connectivity during cognitive reappraisal in chronic low back pain...
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Full-text available
Objectives Mindfulness meditation (MM) is an attention and acceptance–based intervention effective for managing chronic pain. Current literature predominately focuses on the behavioral effects of short-term mindfulness-based programs for pain reduction. However, the long-term potential of MM and its effect on pain processing are less well understoo...
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Background : Combined transcranial magnetic stimulation and electroencephalography (TMS-EEG) is emerging as a powerful technique for interrogating neural circuit dysfunction in psychiatric disorders. Here, we utilized time-frequency analyses to characterize differences in neural oscillatory dynamics between subjects with major depressive disorder (...
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Background Obsessive-compulsive disorder (OCD) is a chronic, disabling mental health condition with limited treatment options available to date. Numerous randomised controlled trials (RCT) have explored the efficacy of repetitive transcranial magnetic stimulation (rTMS) in OCD. This meta-analysis synthesized data from selected RCTs and examined the...
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Full-text available
Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) is an established treatment for refractory depression, however, therapeutic outcomes vary. Mounting evidence suggests that clinical response relates to functional connectivity with the subgenual cingulate cortex (SGC) at the precise DLPFC stimulation s...
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Background: There is growing interest in the potential of neuromodulation options in treatment-resistant obsessive-compulsive disorder (OCD). Magnetic seizure therapy (MST), is a new treatment intervention in which generalized seizures are induced with transcranial magnetic stimulation. We conducted a pilot study to assess the efficacy and cogniti...
Preprint
Full-text available
Objective Interindividual variability of single and paired-pulse TMS data has limited the clinical and experimental applicability of these methods. This study brought together over 60 TMS researchers to create the largest known sample of individual participant single and paired-pulse TMS data to date, enabling a more comprehensive evaluation of fac...
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Full-text available
Background There is evidence to suggest a disruption of gamma-aminobutyric acid (GABA) in autism spectrum disorder (ASD), but findings are mixed. Concurrent electroencephalography and transcranial magnetic stimulation (TMS-EEG) provides a novel method by which to probe GABA-mediated cortical inhibition. Methods With a particular focus on GABAB-erg...
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Objective: The aim of the current study was to attempt to replicate the finding that the individual alpha frequency (IAF) as well as the absolute difference between IAF and 10 Hz stimulation frequency (IAF-prox) is related to treatment outcome. Methods: Correlations were performed to investigate the relationship between IAF-prox and percentage sym...
Article
Antidepressant outcomes to repetitive transcranial magnetic stimulation (rTMS) are better when stimulation is serendipitously delivered to sites of the dorsolateral prefrontal cortex (DLPFC) showing negative (anticorrelated) functional connectivity with the subgenual cingulate cortex (SGC).¹⁻³ This suggests treatment response might be improved via...
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Aberrant connectivity between the dorsolateral prefrontal cortex (DLPFC) and the subgenual cingulate cortex (SGC) has been linked to the pathophysiology of depression. Indirect evidence also links hippocampal activation to the cognitive side effects of seizure treatments. Magnetic seizure therapy (MST) is a novel treatment for patients with treatme...
Article
Objective Our previous research showed high predictive accuracy at differentiating responders from non-responders to repetitive transcranial magnetic stimulation (rTMS) for depression using resting electroencephalography (EEG) and clinical data from baseline and one-week following treatment onset using a machine learning algorithm. In particular, t...
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Background Alzheimer disease has no known cure. As existing pharmacologic interventions only modestly slow cognitive decline, there is a need for new treatments. Recent trials of repetitive transcranial magnetic stimulation (rTMS) have reported encouraging results for improving or stabilizing cognition in patients diagnosed with Alzheimer dementia....
Preprint
Full-text available
BACKGROUND Alzheimer disease has no known cure. As existing pharmacologic interventions only modestly slow cognitive decline, there is a need for new treatments. Recent trials of repetitive transcranial magnetic stimulation (rTMS) have reported encouraging results for improving or stabilizing cognition in patients diagnosed with Alzheimer dementia....
Article
Full-text available
Electroconvulsive therapy (ECT) is a highly effective neuromodulatory intervention for treatment‐resistant major depressive disorder (MDD). Presently, however, understanding of its neurophysiological effects remains incomplete. In the present study, we utilised resting‐state electroencephalography (RS‐EEG) to explore changes in functional connectiv...
Article
Evidence suggests that mindfulness meditation (MM) improves selective attention and reduces distractibility by enhancing top-down neural modulation. Altered P300 and alpha neural activity from MM have been identified and may reflect the neural changes that underpin these improvements. Given the proposed role of alpha activity in supressing processi...
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Importance There is an unmet need for effective treatments for suicidality in mental disorders. Magnetic seizure therapy (MST) has been investigated as an alternative to electroconvulsive therapy, a known effective treatment for suicidality, in the management of treatment-resistant major depressive disorder, with promising findings. Yet, there are...
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Full-text available
Atypical white matter (WM) microstructure is commonly implicated in the neuropathophysiology of autism spectrum disorder (ASD). Fixel based analysis (FBA), at the cutting-edge of diffusion-weighted imaging, can account for crossing WM fibers and can provide indices of both WM micro-and macrostructure. We applied FBA to investigate WM structure betw...
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Full-text available
Background Many studies have attempted to identify the sources of interindividual variability in response to theta-burst stimulation (TBS). However, these studies have been limited by small sample sizes, leading to conflicting results. Objective /Hypothesis: This study brought together over 60 TMS researchers to form the ‘Big TMS Data Collaboratio...
Article
Magnetic seizure therapy (MST) is emerging as a safe and well-tolerated experimental intervention for major depressive disorder (MDD), with very minimal cognitive side-effects. However, the underlying mechanism of action of MST remains uncertain. Here, we used resting-state electroencephalography (RS-EEG) to characterise the physiological effects o...
Article
Objectives: Considerable research has demonstrated the efficacy of repetitive transcranial magnetic stimulation treatment (rTMS) in patients with major depressive disorder (MDD) with differences in effects related to laterality of stimulation. However, no systematic research has explored whether left-handed subjects respond in the same way as right...
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Full-text available
Objectives Mindfulness meditation has been shown to improve working memory (WM). However, brain activity underpinning these improvements is underexplored. In meditation-naïve individuals, increased fronto-midline theta and parieto-occipital alpha oscillations, and steeper 1/f aperiodic activity during WM correlate with better WM performance. Restin...
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Background Transcranial direct current stimulation (tDCS) has been shown to improve working memory (WM) performance in healthy individuals, however effects tend to be modest and variable. Transcranial random noise stimulation (tRNS) can be delivered with a direct-current offset (DC-offset) to induce equal or even greater effects on cortical excitab...
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Full-text available
Transcranial magnetic stimulation (TMS) is an effective treatment for depression but is limited in that the optimal therapeutic target remains unknown. Early TMS trials lacked a focal target, and thus positioned the TMS coil over the prefrontal cortex using scalp measurements. Over time, it became clear that this method leads to variation in the st...