Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
26
result(s) for
"Catts, Stanley"
Sort by:
Gene expression imputation across multiple brain regions provides insights into schizophrenia risk
2019
Transcriptomic imputation approaches combine eQTL reference panels with large-scale genotype data in order to test associations between disease and gene expression. These genic associations could elucidate signals in complex genome-wide association study (GWAS) loci and may disentangle the role of different tissues in disease development. We used the largest eQTL reference panel for the dorso-lateral prefrontal cortex (DLPFC) to create a set of gene expression predictors and demonstrate their utility. We applied DLPFC and 12 GTEx-brain predictors to 40,299 schizophrenia cases and 65,264 matched controls for a large transcriptomic imputation study of schizophrenia. We identified 413 genic associations across 13 brain regions. Stepwise conditioning identified 67 non-MHC genes, of which 14 did not fall within previous GWAS loci. We identified 36 significantly enriched pathways, including hexosaminidase-A deficiency, and multiple porphyric disorder pathways. We investigated developmental expression patterns among the 67 non-MHC genes and identified specific groups of pre- and postnatal expression.
This study uses gene expression predictors for the dorsolateral prefrontal cortex and other brain regions to perform a transcriptomic imputation analysis of schizophrenia, identifying 413 genic associations across 13 brain regions and 36 significantly enriched pathways.
Journal Article
Combat, Posttraumatic Stress Disorder, and Smoking Trajectory in a Cohort of Male Australian Army Vietnam Veterans
2018
Abstract
Background
Whether trauma exposure itself or consequent posttraumatic stress disorder (PTSD) is primarily responsible for smoking and failure to quit remains unclear.
Methods
A cohort of male Australian Vietnam veterans (N = 388) was interviewed twice, 22 and 36 years after their return to Australia using standardized psychiatric diagnostic and health interviews and assessment of combat exposure. The smoking trajectory over time revealed a spectrum of outcomes (never smoked, early quitters, late quitters, and continuing smokers). Analysis used multivariate statistics to assess the relative contributions of combat trauma exposure and PTSD while controlling for potential confounders.
Results
The trajectory of smoking over time revealed that 21.9% of veterans had never smoked, 45.1% had quit smoking by the time of wave 1, 16.2% were current smokers at wave 1 who had quit by the time of wave 2, 2.8% were late adopters who were current smokers, and 13.9% were continuing smokers. Smoking was associated in single-predictor models with demographics, intelligence, combat exposure, PTSD symptom clusters and diagnosis, and alcohol disorders. Multivariate analysis revealed that PTSD, combat, and intelligence were related to the smoking spectrum but, after adding demographics and other Axis I psychiatric diagnoses, only combat remained significant. No PTSD symptom cluster uniquely predicted smoking status.
Conclusions
The results suggest that trauma exposure in the form of military combat may be a more robust predictor of smoking status over time than PTSD. It may be stress itself, rather than poststress disorder, that is more germane to smoking and failure to quit.
Implications
Exposure to traumatic stress and development of PTSD have been implicated separately in the maintenance of smoking. This longitudinal cohort study of smoking in war veterans up to three decades postwar enabled evaluation of traumatic stress exposure in combat and the course of PTSD in smoking and quitting while controlling for intelligence, background disadvantage, and other psychiatric conditions. Combat rather than PTSD emerged as more significant to smoking status, suggesting that it may be the traumatic stress itself rather than the development of a poststress disorder that is more germane to smoking in war veterans.
Journal Article
Reducing long-term antipsychotic use: A therapeutic dead end?
2017
The clinical evidence for antipsychotic medication reducing the mortality rate at all stages of the illness is of high quality and very consistent (summarised by Tiihonen 5 ); the simple truth is that taking more patients off maintenance medication will result in more patients dying unnecessarily – the ultimate therapeutic dead end. Declaration of interest S.V.C. has received funding for acting in the role of an advisory board member, as a sponsored educational speaker, and for research projects from the following pharmaceutical companies: Janssen-Cilag Pty Ltd, Eli Lilly Australia Pty Ltd, Lundbeck Australia Pty Ltd, Novartis Pharmaceuticals Australia Pty Ltd, Pfizer Australia Pty Ltd, Bristol-Myers Squibb Pty Ltd, Sanofi-Aventis Australia Pty Ltd, Hospira Australia Pty Ltd, and AstraZeneca Pty Ltd. He is also a Trustee for the Psychosis Australia Trust and the Queensland Schizophrenia Research Foundation, and a board member of Clearthinking Queensland Ltd. 1 Murray RM, Quattrone D, Natesan S, van Os J, Nordentoft M, Howes O, et al.
Journal Article
Testosterone Is Inversely Related to Brain Activity during Emotional Inhibition in Schizophrenia
by
Weickert, Thomas W.
,
Weickert, Cynthia Shannon
,
Catts, Stanley V.
in
Acoustic Stimulation
,
Adult
,
Androgens
2013
Sex steroids affect cognitive function as well as emotion processing and regulation. They may also play a role in the pathophysiology of schizophrenia. However, the effects of sex steroids on cognition and emotion-related brain activation in schizophrenia are poorly understood. Our aim was to determine the extent to which circulating testosterone relates to brain activation in men with schizophrenia compared to healthy men during cognitive-emotional processing. We assessed brain activation in 18 men with schizophrenia and 22 age-matched healthy men during an emotional go/no-go task using fMRI and measured total serum testosterone levels on the same morning. We performed an ROI analysis to assess the relationship between serum testosterone and brain activation, focusing on cortical regions involved the emotional go/no-go task. Slower RT and reduced accuracy was observed when participants responded to neutral stimuli, while inhibiting responses to negative stimuli. Healthy men showed a robust increase in activation of the middle frontal gyrus when inhibiting responses to negative stimuli, but there was no significant association between activation and serum testosterone level in healthy men. Men with schizophrenia showed a less pronounced increase in activation when inhibiting responses to negative stimuli; however, they did show a strong inverse association between serum testosterone level and activation of the bilateral middle frontal gyrus and left insula. Additionally, increased accuracy during inhibition of response to negative words was associated with both higher serum testosterone levels and decreased activation of the middle frontal gyrus in men with schizophrenia only. We conclude that endogenous hormone levels, even within the normal range, may play an enhanced modulatory role in determining the neural and behavioural response during cognitive-emotional processing in schizophrenia.
Journal Article
Selective Estrogen Receptor Modulation Increases Hippocampal Activity during Probabilistic Association Learning in Schizophrenia
by
Kindler, Jochen
,
Weickert, Cynthia Shannon
,
Catts, Stanley V
in
Association Learning - drug effects
,
Brain research
,
Cognition & reasoning
2015
People with schizophrenia show probabilistic association learning impairment in conjunction with abnormal neural activity. The selective estrogen receptor modulator (SERM) raloxifene preserves neural activity during memory in healthy older men and improves memory in schizophrenia. Here, we tested the extent to which raloxifene modifies neural activity during learning in schizophrenia. Nineteen people with schizophrenia participated in a twelve-week randomized, double-blind, placebo-controlled, cross-over adjunctive treatment trial of the SERM raloxifene administered orally at 120 mg daily to assess brain activity during probabilistic association learning using functional magnetic resonance imaging (fMRI). Raloxifene improved probabilistic association learning and significantly increased fMRI BOLD activity in the hippocampus and parahippocampal gyrus relative to placebo. A separate region of interest confirmatory analysis in 21 patients vs 36 healthy controls showed a positive association between parahippocampal neural activity and learning in patients, but no such relationship in the parahippocampal gyrus of healthy controls. Thus, selective estrogen receptor modulation by raloxifene concurrently increases activity in the parahippocampal gyrus and improves probabilistic association learning in schizophrenia. These results support a role for estrogen receptor modulation of mesial temporal lobe neural activity in the remediation of learning disabilities in both men and women with schizophrenia.
Journal Article
Theory of mind and neurocognition in early psychosis: a quasi-experimental study
2014
Background
People with chronic psychosis often display theory of mind impairments that are not fully accounted for by other, more general neurocognitive deficits. In these patients, both theory of mind and neurocognitive deficits contribute to poor functioning, independently of psychotic symptoms. In young people with recent-onset psychosis, however, it is unclear the extent to which theory of mind impairment is independent of neurocognitive deficits. The primary aim of this study was to examine the evidence for specific theory of mind impairments in early psychosis. A secondary aim was to explore the relations between theory of mind, neurocognition, symptom severity, and functional outcomes.
Methods
Twenty-three patients who were within two years of their first psychotic episode and 19 healthy controls completed theory of mind and neurocognitive batteries. Social functioning, quality of life, and symptom severity were also assessed in patients.
Results
Patients demonstrated deficits in tasks assessing theory of mind and neurocognition relative to controls. Patients’ deficits in theory of mind were evident even after adjusting for their deficits in neurocognition. Neither theory of mind nor neurocognition predicted social functioning or quality of life in this early psychosis sample. Severity of negative symptoms, however, was a significant predictor of both outcomes.
Conclusions
While a specific theory of mind impairment was evident in this early psychosis sample, severity of negative symptoms emerged as the best predictor of poor functional outcome. Further early psychosis research is needed to examine the longitudinal progression of theory of mind impairments – independent of neurocognitive deficits – and their impact on psychosocial function.
Journal Article
Increased power by harmonizing structural MRI site differences with the ComBat batch adjustment method in ENIGMA
2020
A common limitation of neuroimaging studies is their small sample sizes. To overcome this hurdle, the Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) Consortium combines neuroimaging data from many institutions worldwide. However, this introduces heterogeneity due to different scanning devices and sequences. ENIGMA projects commonly address this heterogeneity with random-effects meta-analysis or mixed-effects mega-analysis. Here we tested whether the batch adjustment method, ComBat, can further reduce site-related heterogeneity and thus increase statistical power. We conducted random-effects meta-analyses, mixed-effects mega-analyses and ComBat mega-analyses to compare cortical thickness, surface area and subcortical volumes between 2897 individuals with a diagnosis of schizophrenia and 3141 healthy controls from 33 sites. Specifically, we compared the imaging data between individuals with schizophrenia and healthy controls, covarying for age and sex. The use of ComBat substantially increased the statistical significance of the findings as compared to random-effects meta-analyses. The findings were more similar when comparing ComBat with mixed-effects mega-analysis, although ComBat still slightly increased the statistical significance. ComBat also showed increased statistical power when we repeated the analyses with fewer sites. Results were nearly identical when we applied the ComBat harmonization separately for cortical thickness, cortical surface area and subcortical volumes. Therefore, we recommend applying the ComBat function to attenuate potential effects of site in ENIGMA projects and other multi-site structural imaging work. We provide easy-to-use functions in R that work even if imaging data are partially missing in some brain regions, and they can be trained with one data set and then applied to another (a requirement for some analyses such as machine learning).
•ENIGMA studies commonly conduct meta-analysis or mixed-effects mega-analyses.•We tested if ComBat can better address site effects and increase statistical power.•We compared MRI data between 2897 individuals with schizophrenia and 3141 controls.•ComBat increased the statistical power and significance.•We provide easy-to-use functions in R that work even if there are missing data.
Journal Article
Brain ageing in schizophrenia: evidence from 26 international cohorts via the ENIGMA Schizophrenia consortium
2023
Schizophrenia (SZ) is associated with an increased risk of life-long cognitive impairments, age-related chronic disease, and premature mortality. We investigated evidence for advanced brain ageing in adult SZ patients, and whether this was associated with clinical characteristics in a prospective meta-analytic study conducted by the ENIGMA Schizophrenia Working Group. The study included data from 26 cohorts worldwide, with a total of 2803 SZ patients (mean age 34.2 years; range 18–72 years; 67% male) and 2598 healthy controls (mean age 33.8 years, range 18–73 years, 55% male). Brain-predicted age was individually estimated using a model trained on independent data based on 68 measures of cortical thickness and surface area, 7 subcortical volumes, lateral ventricular volumes and total intracranial volume, all derived from T1-weighted brain magnetic resonance imaging (MRI) scans. Deviations from a healthy brain ageing trajectory were assessed by the difference between brain-predicted age and chronological age (brain-predicted age difference [brain-PAD]). On average, SZ patients showed a higher brain-PAD of +3.55 years (95% CI: 2.91, 4.19;
I
2
= 57.53%) compared to controls, after adjusting for age, sex and site (Cohen’s
d
= 0.48). Among SZ patients, brain-PAD was not associated with specific clinical characteristics (age of onset, duration of illness, symptom severity, or antipsychotic use and dose). This large-scale collaborative study suggests advanced structural brain ageing in SZ. Longitudinal studies of SZ and a range of mental and somatic health outcomes will help to further evaluate the clinical implications of increased brain-PAD and its ability to be influenced by interventions.
Journal Article
Paracingulate sulcus morphology is associated with hallucinations in the human brain
by
Fernyhough, Charles
,
Garrison, Jane R.
,
Haggard, Mark
in
59/57
,
631/378/2620/2618
,
692/699/476
2015
Hallucinations are common in psychiatric disorders, and are also experienced by many individuals who are not mentally ill. Here, in 153 participants, we investigate brain structural markers that predict the occurrence of hallucinations by comparing patients with schizophrenia who have experienced hallucinations against patients who have not, matched on a number of demographic and clinical variables. Using both newly validated visual classification techniques and automated, data-driven methods, hallucinations were associated with specific brain morphology differences in the paracingulate sulcus, a fold in the medial prefrontal cortex, with a 1 cm reduction in sulcal length increasing the likelihood of hallucinations by 19.9%, regardless of the sensory modality in which they were experienced. The findings suggest a specific morphological basis for a pervasive feature of typical and atypical human experience.
Hallucinations can occur in both healthy individuals and patients with psychiatric disorders. Garrison
et al
. here report that specific brain morphology differences in the paracingulate sulcus (PCS) can determine the occurrence of hallucinations in schizophrenia, irrespective of sensory modality.
Journal Article