Search results
Found 16207 matches for
Find out how virtual reality (VR) is used in research to help build confidence and reduce stress in young people. Visit Julia Badger, Lucy Bowes and Aitor Rovira at their IF Festival stand on 28 October between 11 am and 4 pm. Put on a headset, test your reactions and see how your body responds.
Are we designed to be happy?: The neuroscience of making sense of pleasure
The science of happiness is still in its infancy; there is little consensus on how happiness might be best defined, let alone studied. Still, the pursuit of happiness was inscribed in the American Constitution as a fundamental right, and recently governments around the world have started to measure the happiness and well-being of people as a measure on par with gross national product. Whatever it is, happiness is clearly desirable, yet worryingly fleeting. In this chapter, we will describe some of the scientific progress that has been made. We will take our lead from Aristotle, who was interested in the good life; a life lived embedded in meaningful values (Aristotle, 350 BC/1976). He divided the main ingredients into hedonia and eudaimonia. The former is perhaps best translated as "pleasure" (derived from hedus, the sweet taste of honey), while eudaimonia is often translated as "well-being," although it is probably better captured by "flourishing" or "meaningful pleasure.".
Acute neural effects of the mood stabiliser lamotrigine on emotional processing in healthy volunteers: a randomised control trial.
Lamotrigine is an effective mood stabiliser, largely used for the management and prevention of depression in bipolar disorder. The neuropsychological mechanisms by which lamotrigine acts to relieve symptoms as well as its neural effects on emotional processing remain unclear. The primary objective of this current study was to investigate the impact of an acute dose of lamotrigine on the neural response to a well-characterised fMRI task probing implicit emotional processing relevant to negative bias. 31 healthy participants were administered either a single dose of lamotrigine (300 mg, n = 14) or placebo (n = 17) in a randomized, double-blind design. Inside the 3 T MRI scanner, participants completed a covert emotional faces gender discrimination task. Brain activations showing significant group differences were identified using voxel-wise general linear model (GLM) nonparametric permutation testing, with threshold free cluster enhancement (TFCE) and a family wise error (FWE)-corrected cluster significance threshold of p
Exercise rejuvenates microglia and reverses T cell accumulation in the aged female mouse brain.
Slowing and/or reversing brain ageing may alleviate cognitive impairments. Previous studies have found that exercise may mitigate cognitive decline, but the mechanisms underlying this remain largely unclear. Here we provide unbiased analyses of single-cell RNA sequencing data, showing the impacts of exercise and ageing on specific cell types in the mouse hippocampus. We demonstrate that exercise has a profound and selective effect on aged microglia, reverting their gene expression signature to that of young microglia. Pharmacologic depletion of microglia further demonstrated that these cells are required for the stimulatory effects of exercise on hippocampal neurogenesis but not cognition. Strikingly, allowing 18-month-old mice access to a running wheel did by and large also prevent and/or revert T cell presence in the ageing hippocampus. Taken together, our data highlight the profound impact of exercise in rejuvenating aged microglia, associated pro-neurogenic effects and on peripheral immune cell presence in the ageing female mouse brain.
Genetic influence on within-person longitudinal change in anthropometric traits in the UK Biobank.
The causes of temporal fluctuations in adult traits are poorly understood. Here, we investigate the genetic determinants of within-person trait variability of 8 repeatedly measured anthropometric traits in 50,117 individuals from the UK Biobank. We found that within-person (non-directional) variability had a SNP-based heritability of 2-5% for height, sitting height, body mass index (BMI) and weight (P ≤ 2.4 × 10-3). We also analysed longitudinal trait change and show a loss of both average height and weight beyond about 70 years of age. A variant tracking the Alzheimer's risk APOE- E 4 allele (rs429358) was significantly associated with weight loss ( β = -0.047 kg per yr, s.e. 0.007, P = 2.2 × 10-11), and using 2-sample Mendelian Randomisation we detected a relationship consistent with causality between decreased lumbar spine bone mineral density and height loss (bxy = 0.011, s.e. 0.003, P = 3.5 × 10-4). Finally, population-level variance quantitative trait loci (vQTL) were consistent with within-person variability for several traits, indicating an overlap between trait variability assessed at the population or individual level. Our findings help elucidate the genetic influence on trait-change within an individual and highlight disease risks associated with these changes.
Measurement Invariance of the Higher-Order Model of Preschool Anxiety Scale (PAS) across Child Age, Gender, Parental Anxiety, and Pandemic Period in England
The Preschool Anxiety Scale (PAS) is a parent-report scale measuring young children’s anxiety symptoms involving five specific anxiety symptoms (separation anxiety, physical injury fears, social phobia, obsessive-compulsive disorder, generalised anxiety) that load on a higher-order factor representing general anxiety shared by all specific anxiety symptom subtypes. Although the PAS has been widely used to assess anxiety symptoms in young children, few studies have tested its measurement invariance for group comparisons. Using data from a sample of 2,221 children and their parents/carers in England, this study investigated the measurement invariance of the higher-order model of the PAS across child age (4-6 years vs. 6-7 years), gender (girls vs. boys), parental anxiety (low vs. high level), and children’s living circumstances (before vs. after the removal of COVID-19 restrictions). Our findings demonstrated the good factor structure, internal consistency, and convergent validity of the higher-order model of the PAS in all subgroups and supported its configural, metric, scalar invariance across these subgroups. Therefore, the findings suggest that the PAS is a reliable and valid instrument for assessing specific anxiety symptoms and general anxiety among young children in England, and that comparisons can be made between the subgroups under examination. Keywords: Anxiety symptoms, Preschool anxiety scale, Measurement invariance, Group comparisons, Early childhood
A temperature-controlled cooling system for accurate quantitative post-mortem MRI.
PURPOSE: To develop a temperature-controlled cooling system to facilitate accurate quantitative post-mortem MRI and enable scanning of unfixed tissue. METHODS: A water cooling system was built and integrated with a 7T scanner to minimize temperature drift during MRI scans. The system was optimized for operational convenience and rapid deployment to ensure efficient workflow, which is critical for scanning unfixed post-mortem samples. The performance of the system was evaluated using a 7-h diffusion MRI protocol at 7T with a porcine tissue sample. Quantitative T1 , T2 , and ADC maps were interspersed with the diffusion scans at seven different time points to investigate the temperature dependence of MRI tissue parameters. The impact of temperature changes on biophysical model fitting of diffusion MRI data was investigated using simulation. RESULTS: Tissue T1 , T2 , and ADC values remained stable throughout the diffusion MRI scan using the developed cooling system, but varied substantially using a conventional scan setup without temperature control. The cooling system enabled accurate estimation of biophysical model parameters by stabilizing the tissue temperature throughout the diffusion scan, while the conventional setup showed evidence of significantly biased estimation. CONCLUSION: A temperature-controlled cooling system was developed to tackle the challenge of heating in post-mortem imaging, which shows potential to improve the accuracy and reliability of quantitative post-mortem imaging and enables long scans of unfixed tissue.
Self-modulation of motor cortex activity after stroke: a randomized controlled trial.
Real-time functional MRI neurofeedback allows individuals to self-modulate their ongoing brain activity. This may be a useful tool in clinical disorders that are associated with altered brain activity patterns. Motor impairment after stroke has previously been associated with decreased laterality of motor cortex activity. Here we examined whether chronic stroke survivors were able to use real-time fMRI neurofeedback to increase laterality of motor cortex activity and assessed effects on motor performance and on brain structure and function. We carried out a randomized, double-blind, sham-controlled trial (ClinicalTrials.gov: NCT03775915) in which 24 chronic stroke survivors with mild to moderate upper limb impairment experienced three training days of either Real (n = 12) or Sham (n = 12) neurofeedback. Assessments of brain structure, brain function and measures of upper-limb function were carried out before and 1 week after neurofeedback training. Additionally, measures of upper-limb function were repeated 1 month after neurofeedback training. Primary outcome measures were (i) changes in lateralization of motor cortex activity during movements of the stroke-affected hand throughout neurofeedback training days; and (ii) changes in motor performance of the affected limb on the Jebsen Taylor Test (JTT). Stroke survivors were able to use Real neurofeedback to increase laterality of motor cortex activity within (P = 0.019), but not across, training days. There was no group effect on the primary behavioural outcome measure, which was average JTT performance across all subtasks (P = 0.116). Secondary analysis found improvements in the performance of the gross motor subtasks of the JTT in the Real neurofeedback group compared to Sham (P = 0.010). However, there were no improvements on the Action Research Arm Test or the Upper Extremity Fugl-Meyer score (both P > 0.5). Additionally, decreased white-matter asymmetry of the corticospinal tracts was detected 1 week after neurofeedback training (P = 0.008), indicating that the tracts become more similar with Real neurofeedback. Changes in the affected corticospinal tract were positively correlated with participants neurofeedback performance (P = 0.002). Therefore, here we demonstrate that chronic stroke survivors are able to use functional MRI neurofeedback to self-modulate motor cortex activity in comparison to a Sham control, and that training is associated with improvements in gross hand motor performance and with white matter structural changes.
Connectivity-based neurofeedback: dynamic causal modeling for real-time fMRI.
Neurofeedback based on real-time fMRI is an emerging technique that can be used to train voluntary control of brain activity. Such brain training has been shown to lead to behavioral effects that are specific to the functional role of the targeted brain area. However, real-time fMRI-based neurofeedback so far was limited to mainly training localized brain activity within a region of interest. Here, we overcome this limitation by presenting near real-time dynamic causal modeling in order to provide feedback information based on connectivity between brain areas rather than activity within a single brain area. Using a visual-spatial attention paradigm, we show that participants can voluntarily control a feedback signal that is based on the Bayesian model comparison between two predefined model alternatives, i.e. the connectivity between left visual cortex and left parietal cortex vs. the connectivity between right visual cortex and right parietal cortex. Our new approach thus allows for training voluntary control over specific functional brain networks. Because most mental functions and most neurological disorders are associated with network activity rather than with activity in a single brain region, this novel approach is an important methodological innovation in order to more directly target functionally relevant brain networks.
The relationships between hippocampal cerebrovascular reactivity, hippocampal volume, and episodic memory in healthy ageing
AbstractBackgroundCerebrovascular biomarkers such as cerebrovascular reactivity (CVR) have previously been associated with episodic memory. However, the relationship between memory and regional CVR within the hippocampus is not well studied. Moreover, whether this association is affected by hippocampal volume remains to be investigated. This study investigated the associations between hippocampal physiology, structure, and memory in ageing.MethodData from 104 participants (Age: Mean = 77±4.9 years) of the ongoing Oxford Heart and Brain Study was analysed for this study. CVR was assessed by a compensatory change in the blood oxygenation level dependent magnetic resonance imaging (MRI) signal in response to a 5% CO2 challenge, hippocampus volume was measured by structural MRI, and episodic memory was assessed with the Hopkins Verbal Learning Test Revised (HVLT‐R).ResultMean hippocampal CVR decreased with age (β = ‐0.004, p = 0.006). Mean hippocampal CVR was positively associated with mean hippocampal volume (β = 0.11, p = 0.010), and this association was driven by the left hippocampus after correcting for age and sex. Higher hippocampal CVR was also associated with better performance on the HVLT (β = 13.8, p = 0.035). This association was fully mediated by hippocampal volume, suggesting a path from cerebrovascular reactivity to episodic memory (Sobel’s z = 2.16, p = 0.030, see Figure 1).ConclusionThis study presents novel findings showing that hippocampal CVR was associated with episodic memory, and this association was mediated by hippocampal volume. This suggests a pathway by which impairments in hippocampal CVR are associated with worse episodic memory via smaller hippocampal volumes.
Efficacy and effectiveness of antipsychotics in schizophrenia: network meta-analyses combining evidence from randomised controlled trials and real-world data.
BACKGROUND: There is debate about the generalisability of results from randomised clinical trials (RCTs) to real-world settings. Studying outcomes of treatments for schizophrenia can shed light on this issue and inform treatment guidelines. We therefore compared the efficacy and effectiveness of antipsychotics for relapse prevention in schizophrenia and estimated overall treatment effects using all available RCT and real-world evidence. METHODS: We conducted network meta-analyses using individual participant data from Swedish and Finnish national registries and aggregate data from RCTs. The target population was adults (age >18 and <65 years) with schizophrenia and schizoaffective disorder with stabilised symptoms. We analysed each registry separately to obtain hazard ratios (HRs) and 95% CIs for relapse within 6 months post-antipsychotic initiation as our main outcome. Interventions studied were antipsychotics, no antipsychotic use, and placebo. We compared HRs versus a reference drug (oral haloperidol) between registries, and between registry individuals who would be eligible and ineligible for RCTs, using the ratio of HRs. We synthesised evidence using network meta-analysis and compared results from our network meta-analysis of real-world data with our network meta-analysis of RCT data, including oral versus long-acting injectable (LAI) formulations. Finally, we conducted a joint real-world and RCT network meta-analysis. FINDINGS: We included 90 469 individuals from the Swedish and Finnish registries (mean age 45·9 [SD 14·6] years; 43 025 [47·5%] women and 47 467 [52·5%] men, ethnicity data unavailable) and 10 091 individuals from 30 RCTs (mean age 39·6 years [SD 11·7]; 3724 [36·9%] women and 6367 [63·1%] men, 6022 White [59·7%]). We found good agreement in effectiveness of antipsychotics between Swedish and Finnish registries (HR ratio 0·97, 95% CI 0·88-1·08). Drug effectiveness versus no antipsychotic was larger in RCT-eligible than RCT-ineligible individuals (HR ratio 1·40 [1·24-1·59]). Efficacy versus placebo in RCTs was larger than effectiveness versus no antipsychotic in real-world (HR ratio 2·58 [2·02-3·30]). We found no evidence of differences between effectiveness and efficacy for between-drug comparisons (HR ratio vs oral haloperidol 1·17 [0·83-1·65], where HR ratio >1 means superior effectiveness in real-world to RCTs), except for LAI versus oral comparisons (HR ratio 0·73 [0·53-0·99], indicating superior effectiveness in real-world data relative to RCTs). The real-world network meta-analysis showed clozapine was most effective, followed by olanzapine LAI. The RCT network meta-analysis exhibited heterogeneity and inconsistency. The joint real-world and RCT network meta-analysis identified olanzapine as the most efficacious antipsychotic amongst those present in both RCTs and the real world registries. INTERPRETATION: LAI antipsychotics perform slightly better in the real world than according to RCTs. Otherwise, RCT evidence was in line with real-world evidence for most between-drug comparisons, but RCTs might overestimate effectiveness of antipsychotics observed in routine care settings. Our results further the understanding of the generalisability of RCT findings to clinical practice and can inform preferential prescribing guidelines. FUNDING: None.
Treatment Outcomes With Licensed and Unlicensed Stimulant Doses for Adults With Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis.
IMPORTANCE: Stimulants (methylphenidate and amphetamines) are often prescribed at unlicensed doses for adults with attention-deficit/hyperactivity disorder (ADHD). Whether dose escalation beyond US Food and Drug Administration recommendations is associated with positive risk benefits is unclear. OBJECTIVE: To investigate the impact, based on averages, of stimulant doses on treatment outcomes in adults with ADHD and to determine, based on averages, whether unlicensed doses are associated with positive risk benefits compared with licensed doses. DATA SOURCES: Twelve databases, including published (PubMed, Cochrane Library, Embase, Web of Sciences) and unpublished (ClinicalTrials.gov) literature, up to February 22, 2023, without language restrictions. STUDY SELECTION: Two researchers independently screened records to identify double-blinded randomized clinical trials of stimulants against placebo in adults (18 years and older) with ADHD. DATA EXTRACTION AND SYNTHESIS: Aggregate data were extracted and synthesized in random-effects dose-response meta-analyses and network meta-analyses. MAIN OUTCOME MEASURES: Change in ADHD symptoms and discontinuations due to adverse events. RESULTS: A total of 47 randomized clinical trials (7714 participants; mean age, 35 (SD, 11) years; 4204 male [56%]) were included. For methylphenidate, dose-response curves indicated additional reductions of symptoms with increments in doses, but the gains were progressively smaller and accompanied by continued additional risk of adverse events dropouts. Network meta-analyses showed that unlicensed doses were associated with greater reductions of symptoms compared with licensed doses (standardized mean difference [SMD], -0.23; 95% CI, -0.44 to -0.02; very low certainty of evidence), but the additional gain was small and accompanied by increased risk of adverse event dropouts (odds ratio, 2.02; 95% CI, 1.19-3.43; moderate certainty of evidence). For amphetamines, the dose-response curve approached a plateau and increments in doses did not indicate additional reductions of symptoms, but there were continued increments in the risk of adverse event dropouts. Network meta-analysis did not identify differences between unlicensed and licensed doses for reductions of symptoms (SMD, -0.08; 95% CI, -0.24 to 0.08; very low certainty of evidence). CONCLUSIONS AND RELEVANCE: Based on group averages, unlicensed doses of stimulants may not have positive risk benefits compared with licensed doses for adults with ADHD. In general, practitioners should consider unlicensed doses cautiously. Practitioners may trial unlicensed doses if needed and tolerated but should be aware that there may not be large gains in the response to the medication with those further increments in dose. However, the findings are averages and will not generalize to every patient.
Physical Health and Transition to Psychosis in People at Clinical High Risk.
BACKGROUND: The clinical high risk for psychosis (CHR-P) construct represents an opportunity for prevention and early intervention in young adults, but the relationship between risk for psychosis and physical health in these patients remains unclear. METHODS: We conducted a RECORD-compliant clinical register-based cohort study, selecting the long-term cumulative risk of developing a persistent psychotic disorder as the primary outcome. We investigated associations between primary outcome and physical health data with Electronic Health Records at the South London and Maudsley (SLaM) NHS Trust, UK (January 2013-October 2020). We performed survival analyses using Kaplan-Meier curves, log-rank tests, and Cox proportional hazard models. RESULTS: The database included 137 CHR-P subjects; 21 CHR-P developed psychosis during follow-up, and the cumulative incidence of psychosis risk was 4.9% at 1 year and 56.3% at 7 years. Log-rank tests suggested that psychosis risk might change between different levels of nicotine and alcohol dependence. Kaplan-Meier curve analyses indicated that non-hazardous drinkers may have a lower psychosis risk than non-drinkers. In the Cox proportional hazard model, nicotine dependence presented a hazard ratio of 1.34 (95% CI: 1.1-1.64) (p = 0.01), indicating a 34% increase in psychosis risk for every additional point on the Fagerström Test for Nicotine Dependence. CONCLUSIONS: Our findings suggest that a comprehensive assessment of tobacco and alcohol use, diet, and physical activity in CHR-P subjects is key to understanding how physical health contributes to psychosis risk.
‘A commitment to Equality, Diversity and Inclusion’: a conceptual framework for equality of opportunity in Patient and Public Involvement in research
Many research institutions and funders have recently stated their commitment to actively support and promote ‘Equality, Diversity and Inclusion’ (EDI) in various aspects of health research including Patient and Public Involvement (PPI). However, translating this commitment into specific research projects presents significant challenges that existing approaches, practical guidelines and initiatives have not adequately addressed. In this paper, we explore how the lack of clear justifications for the EDI commitment in existing guidelines inadvertently complicates the work of those involved with PPI and we stress the need for conceptual clarity for any EDI effort to yield meaningful results. Our focus centres on the first principle of the EDI discourse, ‘equality’, particularly in the form of ‘equality of opportunity’ as outlined in current guidance provided by the National Institute of Health Research in the United Kingdom. We examine challenges related to justifying and implementing a general, unspecified commitment to equality of opportunity and explain that this reflects a lack of consensus regarding the moral value of PPI in research – a profound problem that remains unaddressed. We then discuss how the presence of several opposing moral perspectives on PPI, makes determining the most appropriate way of addressing barriers to involvement complex and controversial, raising ethical implications for the work of health researchers, PPI specialists and coordinators. Finally we make suggestions on how future research can enrich the concept of ‘equality of opportunity’ in PPI and improve practice. While our primary focus is on the NIHR, a strong advocate of PPI in research, this analysis will point to normative and ethical considerations that may be relevant to other research institutions and funding organisations aiming to promote equality of opportunity in their public and patient involvement strategies.
'Far Away from Home': adolescent inpatient admissions far from home, out of area or to adult wards: a national surveillance study.
BACKGROUND: The increasing prevalence and acuity of mental disorders among children and adolescents have placed pressure on services, including inpatient care, and resulted in young people being admitted at-distance or to adult wards. Little empirical research has investigated such admissions. OBJECTIVE: To determine the incidence, clinical characteristics and 6-month outcomes of patients aged 13-17 years old admitted at-distance (>50 miles from home or out of region) to general adolescent psychiatric wards or to adult psychiatric wards. METHODS: Surveillance over 13 months (February 2021-February 2022) using the Child and Adolescent Psychiatry Surveillance System including baseline and 6-month follow-up questionnaires. FINDINGS: Data were collected about 290 admissions (follow-up rate 99% (288 of 290); sample were 73% female, mean age 15.8 years). The estimated adjusted yearly incidence of at-distance admission was 13.7-16.9 per 100 000 young people 13-17 years old. 38% were admitted >100 miles from home and 8% >200 miles. The most common diagnoses at referral were depression (34%) and autism spectrum disorder (20%); other common referral concerns included suicide risk (80%), emotional dysregulation (53%) and psychotic symptoms (22%). Over two-fifths (41%) waited ≥1 week for a bed, with 55% waiting in general hospital settings. At 6-month follow-up, 20% were still in hospital, the majority in at-distance placements. CONCLUSIONS: At-distance and adult ward admissions for patients aged <18 remain an ongoing challenge for healthcare provision and have an impact on acute hospital resource use. CLINICAL IMPLICATIONS: Long waits in non-specialist settings increase pressure across the healthcare system, highlighting the need to improve local service provision and commissioning to reflect identified clinical needs.