17 research outputs found
Psychotic-like Experiences in Childhood and Adolescence: A Cognitive Neuropsychiatric Approach
Psychotic-like experiences (PLEs) include experiences such as hallucinations and
delusional thinking that can occur in the absence of a clinical disorder. PLEs peak
in middle childhood but appear to spontaneously remit in most children. Nevertheless,
their presence, and particularly their persistence, are associated with an
increased risk of developing later psychosis and poor psychiatric and social outcomes.
However, the mechanisms by which they are generated during childhood
are unclear. Existing models of psychosis cite early life experience and childhood
neurodevelopment as important but often examine these retrospectively. Furthermore,
they suggest mechanisms for how psychotic experiences are generated that
are assumed to apply across the lifespan. This assumption has remained untested,
however. Consequently, in this thesis, I investigated neurocognitive mechanisms
of PLEs in 9-10 year-old-children using data from the Adolescent Brain Cognitive
Development (ABCD) study. In Study 1, I examined whether the established mechanistic
risk factors in adult psychosis â affective symptoms, traumatic experiences,
cognitive function, structural brain changes â are associated with PLEs using network
analysis, finding only that depression-related symptoms were associated with
PLEs. In Study 2, I tested whether fMRI activation in striatal reward pathways was
associated with PLEs in children, as this is an established finding in adults. This
study found no strong evidence for alteration to striatal reward pathways with a
high likelihood that it was absent, rather than undetectable. Given the prognostic
and aetiological important of persistence of PLEs, in Study 3, I tested affective,
trauma-related, cognitive and striatal reward activation predictors of 1-year PLE
persistence. Only depressive symptoms were substantial predictors. Depressive
symptoms emerged as the strongest predictor of PLEs at this developmental stage,
both cross-sectionally and longitudinally. The findings indicate that PLEs in childhood
are not a âmini psychosis syndromeâ and developmental-stage specific models
of psychotic experiences in children are required
Reward Processing in Children With Psychotic-Like Experiences.
Alterations to striatal reward pathways have been identified in individuals with psychosis. They are hypothesized to be a key mechanism that generate psychotic symptoms through the production of aberrant attribution of motivational salience and are proposed to result from accumulated childhood adversity and genetic risk, making the striatal system hyper-responsive to stress. However, few studies have examined whether children with psychotic-like experiences (PLEs) also exhibit these alterations, limiting our understanding of how differences in reward processing relate to hallucinations and delusional ideation in childhood. Consequently, we examined whether PLEs and PLE-related distress were associated with reward-related activation in the nucleus accumbens (NAcc). The sample consisted of children (N = 6718) from the Adolescent Brain Cognitive Development (ABCD) study aged 9-10 years who had participated in the Monetary Incentive Delay (MID) task in functional MRI. We used robust mixed-effects linear regression models to investigate the relationship between PLEs and NAcc activation during the reward anticipation and reward outcome stages of the MID task. Analyses were adjusted for gender, household income, ethnicity, depressive symptoms, movement in the scanner, pubertal development, scanner ID, subject and family ID. There was no reliable association between PLEs and alterations to anticipation- or outcome-related striatal reward processing. We discuss the implications for developmental models of psychosis and suggest a developmental delay model of how PLEs may arise at this stage of development
Exposure to potentially morally injurious events in U.K. health and social care workers during COVID-19: Associations with PTSD and complex PTSD
OBJECTIVE: Health and social care workers (HSCWs) have been shown to be at risk of exposure to potentially morally injurious events (PMIEs) and mental health problems during the COVID-19 pandemic. This study aimed to examine associations between exposure to PMIEs and meeting threshold criteria for probable posttraumatic stress disorder (PTSD) and probable complex PTSD (CPTSD) in U.K. HSCWs immediately after the peak of the first COVID-19 wave. METHOD: Frontline HSCWs from across the United Kingdom working in diverse roles in hospitals, nursing or care homes, and other community settings were recruited to the Frontline-COVID study via social media. Participants (n = 1,056) completed a cross-sectional online survey (May 27, 2020-July 23, 2020) which assessed exposure to PMIEs (nine-item Moral Injury Events Scale), and meeting symptom thresholds for probable PTSD and probable CPTSD (International Trauma Questionnaire). RESULTS: PMIEs related to witnessing others' wrongful actions and betrayal events were more commonly endorsed than perceived self-transgressions. The rate of probable International Classification of Diseases, 11th Revision (ICD-11) PTSD was 8.3%, and of probable ICD-11 CPTSD was 14.2%. Betrayal-related PMIEs were a significant predictor of probable PTSD or probable CPTSD, together with having been redeployed during the pandemic. The only variable that differentially predicted probable CPTSD as compared with probable PTSD was not having had reliable access to personal protective equipment; none of the PMIE types were differential predictors for screening positive for probable PTSD versus probable CPTSD. CONCLUSIONS: Exposure to PIMEs could be important for PTSD and CPTSD development. Interventions for moral injury in HSCWs should be investigated. (PsycInfo Database Record (c) 2023 APA, all rights reserved)
Recommended from our members
Impact on mental health care and on mental health service users of the COVID-19 pandemic: a mixed methods survey of UK mental health care staff
PURPOSE: The COVID-19 pandemic has potential to disrupt and burden the mental health care system, and to magnify inequalities experienced by mental health service users. METHODS: We investigated staff reports regarding the impact of the COVID-19 pandemic in its early weeks on mental health care and mental health service users in the UK using a mixed methods online survey. Recruitment channels included professional associations and networks, charities, and social media. Quantitative findings were reported with descriptive statistics, and content analysis conducted for qualitative data. RESULTS: 2,180 staff from a range of sectors, professions, and specialties participated. Immediate infection control concerns were highly salient for inpatient staff, new ways of working for community staff. Multiple rapid adaptations and innovations in response to the crisis were described, especially remote working. This was cautiously welcomed but found successful in only some clinical situations. Staff had specific concerns about many groups of service users, including people whose conditions are exacerbated by pandemic anxieties and social disruptions; people experiencing loneliness, domestic abuse and family conflict; those unable to understand and follow social distancing requirements; and those who cannot engage with remote care. CONCLUSION: This overview of staff concerns and experiences in the early COVID-19 pandemic suggests directions for further research and service development: we suggest that how to combine infection control and a therapeutic environment in hospital, and how to achieve effective and targeted tele-health implementation in the community, should be priorities. The limitations of our convenience sample must be noted
Psychosis Endophenotypes:A Gene-Set-Specific Polygenic Risk Score Analysis
BACKGROUND AND HYPOTHESIS: Endophenotypes can help to bridge the gap between psychosis and its genetic predispositions, but their underlying mechanisms remain largely unknown. This study aims to identify biological mechanisms that are relevant to the endophenotypes for psychosis, by partitioning polygenic risk scores into specific gene sets and testing their associations with endophenotypes. STUDY DESIGN: We computed polygenic risk scores for schizophrenia and bipolar disorder restricted to brain-related gene sets retrieved from public databases and previous publications. Three hundred and seventy-eight gene-set-specific polygenic risk scores were generated for 4506 participants. Seven endophenotypes were also measured in the sample. Linear mixed-effects models were fitted to test associations between each endophenotype and each gene-set-specific polygenic risk score. STUDY RESULTS: After correction for multiple testing, we found that a reduced P300 amplitude was associated with a higher schizophrenia polygenic risk score of the forebrain regionalization gene set (mean difference per SD increase in the polygenic risk score: -1.15 ”V; 95% CI: -1.70 to -0.59 ”V; P = 6 à 10-5). The schizophrenia polygenic risk score of forebrain regionalization also explained more variance of the P300 amplitude (R2 = 0.032) than other polygenic risk scores, including the genome-wide polygenic risk scores. CONCLUSIONS: Our finding on reduced P300 amplitudes suggests that certain genetic variants alter early brain development thereby increasing schizophrenia risk years later. Gene-set-specific polygenic risk scores are a useful tool to elucidate biological mechanisms of psychosis and endophenotypes, offering leads for experimental validation in cellular and animal models
Recommended from our members
Early impacts of the COVID-19 pandemic on mental health care and on people with mental health conditions: framework synthesis of international experiences and responses
PURPOSE: The COVID-19 pandemic has many potential impacts on people with mental health conditions and on mental health care, including direct consequences of infection, effects of infection control measures and subsequent societal changes. We aimed to map early impacts of the pandemic on people with pre-existing mental health conditions and services they use, and to identify individual and service-level strategies adopted to manage these.
METHODS: We searched for relevant material in the public domain published before 30 April 2020, including papers in scientific and professional journals, published first person accounts, media articles, and publications by governments, charities and professional associations. Search languages were English, French, German, Italian, Spanish, and Mandarin Chinese. Relevant content was retrieved and summarised via a rapid qualitative framework synthesis approach.
RESULTS: We found 872 eligible sources from 28 countries. Most documented observations and experiences rather than reporting research data. We found many reports of deteriorations in symptoms, and of impacts of loneliness and social isolation and of lack of access to services and resources, but sometimes also of resilience, effective self-management and peer support. Immediate service challenges related to controlling infection, especially in inpatient and residential settings, and establishing remote working, especially in the community. We summarise reports of swiftly implemented adaptations and innovations, but also of pressing ethical challenges and concerns for the future.
CONCLUSION: Our analysis captures the range of stakeholder perspectives and experiences publicly reported in the early stages of the COVID-19 pandemic in several countries. We identify potential foci for service planning and research
Psychosis Endophenotypes: A Gene-Set-Specific Polygenic Risk Score Analysis
BACKGROUND AND HYPOTHESIS: Endophenotypes can help to bridge the gap between psychosis and its genetic predispositions, but their underlying mechanisms remain largely unknown. This study aims to identify biological mechanisms that are relevant to the endophenotypes for psychosis, by partitioning polygenic risk scores into specific gene sets and testing their associations with endophenotypes. STUDY DESIGN: We computed polygenic risk scores for schizophrenia and bipolar disorder restricted to brain-related gene sets retrieved from public databases and previous publications. Three hundred and seventy-eight gene-set-specific polygenic risk scores were generated for 4506 participants. Seven endophenotypes were also measured in the sample. Linear mixed-effects models were fitted to test associations between each endophenotype and each gene-set-specific polygenic risk score. STUDY RESULTS: After correction for multiple testing, we found that a reduced P300 amplitude was associated with a higher schizophrenia polygenic risk score of the forebrain regionalization gene set (mean difference per SD increase in the polygenic risk score: -1.15 ”V; 95% CI: -1.70 to -0.59 ”V; P = 6 à 10-5). The schizophrenia polygenic risk score of forebrain regionalization also explained more variance of the P300 amplitude (R2 = 0.032) than other polygenic risk scores, including the genome-wide polygenic risk scores. CONCLUSIONS: Our finding on reduced P300 amplitudes suggests that certain genetic variants alter early brain development thereby increasing schizophrenia risk years later. Gene-set-specific polygenic risk scores are a useful tool to elucidate biological mechanisms of psychosis and endophenotypes, offering leads for experimental validation in cellular and animal models
Genetic copy number variants, cognition and psychosis: a meta-analysis and a family study
The burden of large and rare copy number genetic variants (CNVs) as well as certain specific CNVs increase the risk of developing schizophrenia. Several cognitive measures are purported schizophrenia endophenotypes and may represent an intermediate point between genetics and the illness. This paper investigates the influence of CNVs on cognition. We conducted a systematic review and meta-analysis of the literature exploring the effect of CNV burden on general intelligence. We included ten primary studies with a total of 18,847 participants and found no evidence of association. In a new psychosis family study, we investigated the effects of CNVs on specific cognitive abilities. We examined the burden of large and rare CNVs (>200 kb, <1% MAF) as well as known schizophrenia-associated CNVs in patients with psychotic disorders, their unaffected relatives and controls (N = 3428) from the Psychosis Endophenotypes International Consortium (PEIC). The carriers of specific schizophrenia-associated CNVs showed poorer performance than non-carriers in immediate (P = 0.0036) and delayed (P = 0.0115) verbal recall. We found suggestive evidence that carriers of schizophrenia-associated CNVs had poorer block design performance (P = 0.0307). We do not find any association between CNV burden and cognition. Our findings show that the known high-risk CNVs are not only associated with schizophrenia and other neurodevelopmental disorders, but are also a contributing factor to impairment in cognitive domains such as memory and perceptual reasoning, and act as intermediate biomarkers of disease risk.This work was supported by the Medical Research Council (G0901310) and the Wellcome Trust (grants 085475/B/08/Z, 085475/Z/08/Z). This study was
supported by the NIHR Biomedical Research Centre at University
College London Hospitals NHS Foundation Trust and University
College London and by the NIHR Biomedical Research Centre for
Mental Health at the South London and Maudsley NHS Foundation
Trust at Kingâs College London. Further support to EB: Mental Health
Research UKâs John Grace QC award, BMA Margaret Temple grants
2016 and 2006, MRCâKorean Health Industry Development Institute
Partnering Award (MC_PC_16014), MRC New Investigator Award
and a MRC Centenary Award (G0901310), National Institute of
Health Research UK post-doctoral fellowship, the Psychiatry Research
Trust, the Schizophrenia Research Fund, the Brain and Behaviour
Research foundationâs NARSAD Young Investigator Awards 2005,
2008, Wellcome Trust Research Training Fellowship, the NIHR
Biomedical Research Centre at UCLH, and the NIHR Biomedical
Research Centre for Mental Health at the South London and Maudsley
NHS Foundation Trust and Institute of Psychiatry Kingâs College
London. Further support to co-authors: The Brain and Behaviour
Research foundationâs (NARSADâs) Young Investigator Award
(Grant 22604, awarded to CI). The BMA Margaret Temple grant 2016
to JT. A 2014 European Research Council Marie Curie award to A
DĂez-Revuelta. HI has received funding from the European Unionâs
Horizon 2020 research and innovation programme under the Marie
Sklodowska-Curie grant agreement No 747429. A Medical Research
Council doctoral studentship to JH-S, IA-Z and AB. A Mental Health
Research UK studentship to RM. VB is supported by a Wellcome
Trust Seed Award in Science (200589/Z/16/Z). FWO Senior Clinical
Fellowship to RvW. The infrastructure for the GROUP consortium is
funded through the Geestkracht programme of the Dutch Health
Research Council (ZON-MW, grant number 10-000-1001), and
matching funds from participating pharmaceutical companies (Lundbeck, AstraZeneca, Eli Lilly, Janssen Cilag) and universities and
mental health care organisations (Amsterdam: Academic Psychiatric
Centre of the Academic Medical Centre and the mental health institutions: GGZ Ingeest, Arkin, Dijk en Duin, GGZ Rivierduinen,
Erasmus Medical Centre, GGZ Noord Holland Noord. Groningen:
University Medical Centre Groningen and the mental health institutions: Lentis, GGZ Friesland, GGZ Drenthe, Dimence, Mediant,
GGNet Warnsveld, Yulius Dordrecht and Parnassia psycho-medical
centre The Hague. Maastricht: Maastricht University Medical Centre
and the mental health institutions: GGZ Eindhoven en De Kempen,
GGZ Breburg, GGZ Oost-Brabant, Vincent van Gogh voor Geestelijke
Gezondheid, Mondriaan, Virenze riagg, Zuyderland GGZ, MET ggz,
Universitair Centrum Sint-Jozef Kortenberg, CAPRI University of
Antwerp, PC Ziekeren Sint-Truiden, PZ Sancta Maria Sint-Truiden,
GGZ Overpelt, OPZ Rekem. Utrecht: University Medical Centre Utrecht and the mental health institutions Altrecht, GGZ Centraal and
Delta). The Santander cohort was supported by Instituto de Salud
Carlos III (PI020499, PI050427, PI060507), SENY FundaciĂł (CI
2005-0308007), Fundacion Ramón Areces and Fundacion Marqués de
Valdecilla (API07/011, API10/13). We thank Valdecilla Biobank for
providing the biological PAFIP samples and associated data included
in this study and for its help in the technical execution of this work; we
also thank IDIVAL Neuroimaging Unit for its help in the acquisition
and processing of imaging PAFIP data