Inferring stochastic group interactions within structured populations via coupled autoregression.

The internal behaviour of a population is an important feature to take account of when modelling its dynamics. In line with kin selection theory, many social species tend to cluster into distinct groups in order to enhance their overall population fitness. Temporal interactions between populations are often modelled using classical mathematical models, but these sometimes fail to delve deeper into the, often uncertain, relationships within populations. Here, we introduce a stochastic framework that aims to capture the interactions of animal groups and an auxiliary population over time. We demonstrate the model's capabilities, from a Bayesian perspective, through simulation studies and by fitting it to predator-prey count time series data. We then derive an approximation to the group correlation structure within such a population, while also taking account of the effect of the auxiliary population. We finally discuss how this approximation can lead to ecologically realistic interpretations in a predator-prey context. This approximation also serves as verification to whether the population in question satisfies our various assumptions. Our modelling approach will be useful for empiricists for monitoring groups within a conservation framework and also theoreticians wanting to quantify interactions, to study cooperation and other phenomena within social populations.

Perception of COVID-19 threat, low self-efficacy, and external locus of control lead to psychological distress during the COVID-19 pandemic.

While it is well documented that the COVID-19 pandemic has had critical consequences for individuals' mental health, few studies to date have investigated the influence of psychological factors on psychological distress in the context of COVID-19. This study explores the influences of self-efficacy, health locus of control, and COVID-19 threat perception on psychological distress (DASS-21). 180 adults completed an online set of standardised questionnaires. Results indicated that self-efficacy had a significant relationship with all three subscales of psychological distress. However, COVID-19 threat perception was significantly associated with stress. External health locus of control was significantly associated with depression by the chance externality subscale, and stress by the powerful others externality subscale. Additionally, external health locus of control was found to moderate the relationship between COVID-19 threat perception and depression.

Safety and usability of proning pillows in intensive care: A scoping review.

OBJECTIVES: Proning is an established technique for the care of intubated patients with severe respiratory failure. Positioning devices used to support the head and body of patients placed in the prone position are often associated with the formation of pressure injuries. Despite robust literature on the prevention and monitoring of pressure injuries, little is described about the role of proning pillows on pressure injuries. The objective of this review is to understand the extent of evidence pertaining to the safety and usability of different types of proning pillows in the intensive care setting. REVIEW METHOD: A scoping review of the literature was completed using predefined search terms in three databases and identified 296 articles. An additional 26 were included from reference lists. Twenty studies are included in the analysis; most were published in the past 3 years, with >50% in surgical settings. DATA SOURCES: Three databases were searched: PubMed, Scopus, and EMBASE. REVIEW METHODS: The review followed the PRISMA Extension for Scoping Reviews, and data were reviewed using Covidence. RESULTS: The most prevalent proning pillow is a standard, noncontoured foam head positioner. It is responsible for the majority of facial pressure injuries in all settings of care. Memory foam pillows and helmet-based systems offer improved surface pressure distribution, although their usability in the intensive care setting remains poorly studied. Inflatable air-cell-based devices present an alternative, but the lack of supporting research and the costs may explain their poor uptake. Several articles proposed the use of pressure sensor systems to evaluate devices. We propose a set of ergonomic parametres to consider when choosing or designing a positioning device for proned patients. CONCLUSION: The evidence pertaining to the safety and usability of proning pillows in the intensive care setting is scarce, which provides opportunities for future research to improve the efficacy in the prevention of pressure injuries and the user experience.

Psychosocial hazards, posttraumatic stress disorder, complex posttraumatic stress disorder, depression, and anxiety in the U.K. rail industry: A cross-sectional study.

This study examined posttraumatic stress disorder (PTSD), complex PTSD, depression, and anxiety among U.K. rail workers. A cross-sectional survey examining exposure to seven psychosocial hazards (bullying/harassment; verbal abuse; physical and sexual assault; and hearing about, seeing the aftermath of, or witnessing a fatality), working conditions, physical health, and the impact of COVID-19 was administered to 3,912 participants. Outcome measures were the ITQ, PHQ-9, and GAD-7. Among trauma-exposed participants, 24.3% met the criteria for PTSD or CPTSD; 38.6% and 29.2% of all participants scored in the moderate-to-severe range on the PHQ-9 and GAD-7, respectively. Data were analyzed using logistic and linear regression. Bullying/harassment was positively associated with GAD-7 scores, f2 = .001, and PTSD and CPTSD, ORs = 1.83-2.02. Hearing about and witnessing a fatality were associated with PTSD and CPTSD, ORs = 1.77-2.10. Poorer ergonomics at work were positively associated with PHQ-9 and GAD-7 scores, f2 = .001. Higher job satisfaction was associated with lower odds of PTSD and CPTSD, ORs = 0.87-0.91, and negatively associated with PHQ-9 and GAD-7 scores, f2 = .008-.01. Work intensity was associated with PTSD and CPTSD, ORs = 1.79-1.83, and positively associated with PHQ-9 and GAD-7 scores, f2 = .02-.03. Reporting more physical health problems was associated with PTSD, OR = 1.07, and positively associated with GAD-7 and PHQ-9 scores, f2 = .008-.01. The results suggest bullying/harassment and work intensity are important variables in employee mental health and could drive future research and industry initiatives.

Problematic Internet Use among adolescents: Spanish validation of the Compulsive Internet Use Scale (CIUS). / Uso Problemático de Internet en adolescentes: Validación en español de la Escala de Uso Compulsivo de Internet (CIUS).

Problematic use of the Internet among adolescents has risen in the last decade. The Compulsive Internet Use Scale (CIUS) is one of the most frequently internationally-used tools developed to assess Problematic Internet Use (PIU). However, evidence concerning its validity and reliability in its Spanish version for the adolescent population is currently lacking. Thus, the main goal of the present study was to analyse the psychometric properties of CIUS scores in a large sample of Spanish adolescents. The sample consisted of 1,790 participants (53.7% female, mean age = 15.70 years old, SD = 1.26). The one-dimensional model displayed appropriate goodness of fit indices after error covariance of five items were allowed to correlate. Strong measurement invariance was found for the one-dimensional model across age and gender. The McDonald's Omega coefficient for the total score was 0.91. Furthermore, PIU was positively associated with different indicators of poor wellbeing and psychological difficulties and negatively associated with prosocial behaviour, self-esteem and sense of belonging to the educational centre. The study provided evidence of validity for the CIUS, confirming its utility for screening PIU in non-clinical adolescents.

La Escala de Uso Compulsivo de Internet (Compulsive Internet Use Scale, CIUS) es uno de los instrumentos más empleados a nivel internacional para evaluar el Uso Problemático de Internet (UPI). Sin embargo, no existen evidencias de validez y fiabilidad de las puntuaciones de la versión española en población adolescente. Por ello, el principal objetivo de este estudio fue analizar las propiedades psicométricas de las puntuaciones de la CIUS en una muestra representativa de adolescentes españoles. La muestra contó con 1.790 participantes (53,7% mujeres, edad media = 15,70 años, DT = 1,26). El análisis de la estructura interna del instrumento mostró unos índices de bondad de ajuste apropiados para el modelo unidimensional después de que se permitiera correlacionar la covarianza de errores de cinco ítems. Se encontró invarianza de medición fuerte para el modelo unidimensional en las variables de edad y género. El coeficiente Omega de McDonald para la puntuación total fue 0,91. Además, el UPI se asoció positivamente con diferentes indicadores de malestar y dificultades psicológicas y negativamente con el comportamiento prosocial, la autoestima y el sentido de pertenencia al centro educativo. Este estudio arroja evidencias de validez de la CIUS, y sugiere que puede ser una herramienta apropiada para medir el UPI en adolescentes de la población general.

The CORE service improvement programme for mental health crisis resolution teams: results from a cluster-randomised trial.

BACKGROUND: Crisis resolution teams (CRTs) offer brief, intensive home treatment for people experiencing mental health crisis. CRT implementation is highly variable; positive trial outcomes have not been reproduced in scaled-up CRT care. AIMS: To evaluate a 1-year programme to improve CRTs' model fidelity in a non-masked, cluster-randomised trial (part of the Crisis team Optimisation and RElapse prevention (CORE) research programme, trial registration number: ISRCTN47185233). METHOD: Fifteen CRTs in England received an intervention, informed by the US Implementing Evidence-Based Practice project, involving support from a CRT facilitator, online implementation resources and regular team fidelity reviews. Ten control CRTs received no additional support. The primary outcome was patient satisfaction, measured by the Client Satisfaction Questionnaire (CSQ-8), completed by 15 patients per team at CRT discharge (n = 375). Secondary outcomes: CRT model fidelity, continuity of care, staff well-being, in-patient admissions and bed use and CRT readmissions were also evaluated. RESULTS: All CRTs were retained in the trial. Median follow-up CSQ-8 score was 28 in each group: the adjusted average in the intervention group was higher than in the control group by 0.97 (95% CI -1.02 to 2.97) but this was not significant (P = 0.34). There were fewer in-patient admissions, lower in-patient bed use and better staff psychological health in intervention teams. Model fidelity rose in most intervention teams and was significantly higher than in control teams at follow-up. There were no significant effects for other outcomes. CONCLUSIONS: The CRT service improvement programme did not achieve its primary aim of improving patient satisfaction. It showed some promise in improving CRT model fidelity and reducing acute in-patient admissions.

Peer-supported self-management for people discharged from a mental health crisis team: a randomised controlled trial.

BACKGROUND: High resource expenditure on acute care is a challenge for mental health services aiming to focus on supporting recovery, and relapse after an acute crisis episode is common. Some evidence supports self-management interventions to prevent such relapses, but their effect on readmissions to acute care following a crisis is untested. We tested whether a self-management intervention facilitated by peer support workers could reduce rates of readmission to acute care for people discharged from crisis resolution teams, which provide intensive home treatment following a crisis. METHODS: We did a randomised controlled superiority trial recruiting participants from six crisis resolution teams in England. Eligible participants had been on crisis resolution team caseloads for at least a week, and had capacity to give informed consent. Participants were randomly assigned to intervention and control groups by an unmasked data manager. Those collecting and analysing data were masked to allocation, but participants were not. Participants in the intervention group were offered up to ten sessions with a peer support worker who supported them in completing a personal recovery workbook, including formulation of personal recovery goals and crisis plans. The control group received the personal recovery workbook by post. The primary outcome was readmission to acute care within 1 year. This trial is registered with ISRCTN, number 01027104. FINDINGS: 221 participants were assigned to the intervention group versus 220 to the control group; primary outcome data were obtained for 218 versus 216. 64 (29%) of 218 participants in the intervention versus 83 (38%) of 216 in the control group were readmitted to acute care within 1 year (odds ratio 0·66, 95% CI 0·43-0·99; p=0·0438). 71 serious adverse events were identified in the trial (29 in the treatment group; 42 in the control group). INTERPRETATION: Our findings suggest that peer-delivered self-management reduces readmission to acute care, although admission rates were lower than anticipated and confidence intervals were relatively wide. The complexity of the study intervention limits interpretability, but assessment is warranted of whether implementing this intervention in routine settings reduces acute care readmission. FUNDING: National Institute for Health Research.

Psychotic traits in musicians.

The association of music with madness is very longstanding. But is it more than myth, and if so what is the nature of this relationship? We tested the hypotheses that musicians possess greater schizotypy and symptoms of bipolar disorder. A total of 102 musicians were found to have greater positive and negative schizotypal traits when compared to matched norms on the shortened Oxford-Liverpool Inventory of Feelings and Experiences. Based on the Mood Disorder Questionnaire, 10.8% of musicians also met criteria for lifetime bipolar disorder. Rock musicians appeared to have greater symptoms than those performing in other musical genres.

Dimensional assessment of schizotypal, psychotic, and other psychiatric traits in children and their parents: development and validation of the Childhood Oxford-Liverpool Inventory of Feelings and Experiences on a representative US sample.

BACKGROUND: Healthy functioning relies on a variety of perceptual, cognitive, emotional, and behavioral abilities that are distributed throughout the normal population. Variation in these traits define the wide range of neurodevelopmental (NDD) and neuropsychiatric (NPD) disorders. Here, we introduce a new measure for assessing these traits in typically developing children and children at risk for NDD and NPD from age 2 to 18 years. METHOD: The Childhood Oxford-Liverpool Inventory of Feelings and Experiences (CO-LIFE) was created as a dimensional, parent-report measure of schizotypal and psychotic traits in the general population. Parents of 2,786 children also self-reported on an adapted version of the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE-US). RESULTS: The CO-LIFE resulted in continuous distributions for the total score and for each of three factor analytically-derived subscales. Item response theory (IRT) analyses indicated strong reliability across the score range for the O-LIFE-US and the CO-LIFE. Internal consistency and test-retest reliability were high across all scales. Parent-child intraclass correlations were consistent with high heritability. The scales discriminated participants who reported a lifetime psychiatric diagnosis from those who reported no diagnosis. The O-LIFE-US and CO-LIFE scores correlated positively with the Social Responsiveness Scale 2 (SRS-2) indicating good convergent validity. CONCLUSIONS: Like the original O-LIFE, the O-LIFE-US and the CO-LIFE are valid and reliable tools that reflect the spectrum of psychiatric and schizotypal traits in the general population. Such scales are necessary for conducting family studies that aim to examine a range of psychological and behavioral traits in both children and adults and are well-suited for the Research Domain Criteria (RDoC) initiative of the NIMH.

Crisis resolution and home treatment: stakeholders' views on critical ingredients and implementation in England.

BACKGROUND: Crisis resolution teams (CRTs) can provide effective home-based treatment for acute mental health crises, although critical ingredients of the model have not been clearly identified, and implementation has been inconsistent. In order to inform development of a more highly specified CRT model that meets service users' needs, this study used qualitative methods to investigate stakeholders' experiences and views of CRTs, and what is important in good quality home-based crisis care. METHOD: Semi-structured interviews and focus groups were conducted with service users (n = 41), carers (n = 20) and practitioners (CRT staff, managers and referrers; n = 147, 26 focus groups, 9 interviews) in 10 mental health catchment areas in England, and with international CRT developers (n = 11). Data were analysed using thematic analysis. RESULTS: Three domains salient to views about optimal care were identified. 1. The organisation of CRT care: Providing a rapid initial responses, and frequent home visits from the same staff were seen as central to good care, particularly by service users and carers. Being accessible, reliable, and having some flexibility were also valued. Negative experiences of some referral pathways, and particularly lack of staff continuity were identified as problematic. 2. The content of CRT work: Emotional support was at the centre of service users' experiences. All stakeholder groups thought CRTs should involve the whole family, and offer a range of interventions. However, carers often feel excluded, and medication is often prioritised over other forms of support. 3. The role of CRTs within the care system: Gate-keeping admissions is seen as a key role for CRTs within the acute care system. Service users and carers report that recovery is quicker compared to in-patient care. Lack of knowledge and misunderstandings about CRTs among referrers are common. Overall, levels of stakeholder agreement about the critical ingredients of good crisis care were high, although aspects of this were not always seen as achievable. CONCLUSIONS: Stakeholders' views about optimal CRT care suggest that staff continuity, carer involvement, and emotional and practical support should be prioritised in service improvements and more clearly specified CRT models.

Development of a measure of model fidelity for mental health Crisis Resolution Teams.

BACKGROUND: Crisis Resolution Teams (CRTs) provide short-term intensive home treatment to people experiencing mental health crisis. Trial evidence suggests CRTs can be effective at reducing hospital admissions and increasing satisfaction with acute care. When scaled up to national level however, CRT implementation and outcomes have been variable. We aimed to develop and test a fidelity scale to assess adherence to a model of best practice for CRTs, based on best available evidence. METHODS: A concept mapping process was used to develop a CRT fidelity scale. Participants (n = 68) from a range of stakeholder groups prioritised and grouped statements (n = 72) about important components of the CRT model, generated from a literature review, national survey and qualitative interviews. These data were analysed using Ariadne software and the resultant cluster solution informed item selection for a CRT fidelity scale. Operational criteria and scoring anchor points were developed for each item. The CORE CRT fidelity scale was then piloted in 75 CRTs in the UK to assess the range of scores achieved and feasibility for use in a 1-day fidelity review process. Trained reviewers (n = 16) rated CRT service fidelity in a vignette exercise to test the scale's inter-rater reliability. RESULTS: There were high levels of agreement within and between stakeholder groups regarding the most important components of the CRT model. A 39-item measure of CRT model fidelity was developed. Piloting indicated that the scale was feasible for use to assess CRT model fidelity and had good face validity. The wide range of item scores and total scores across CRT services in the pilot demonstrate the measure can distinguish lower and higher fidelity services. Moderately good inter-rater reliability was found, with an estimated correlation between individual ratings of 0.65 (95% CI: 0.54 to 0.76). CONCLUSIONS: The CORE CRT Fidelity Scale has been developed through a rigorous and systematic process. Promising initial testing indicates its value in assessing adherence to a model of CRT best practice and to support service improvement monitoring and planning. Further research is required to establish its psychometric properties and international applicability.

Renaming schizophrenia to reduce stigma: comparison with the case of bipolar disorder.

Renaming disorders to change public beliefs and attitudes remains controversial. This study compared the potentially destigmatising effects of renaming schizophrenia with the effects of renaming bipolar disorder by comparing the label 'schizophrenia' to 'integration disorder', and 'bipolar disorder' to 'manic depression', in 1621 lay participants. 'Bipolar disorder' was associated with less fear and social distance than 'manic depression'. 'Integration disorder' was associated with increased endorsement of a biopsychosocial cause and reduced attributions of dangerousness but also increased social distance, highlighting the complex effects renaming has on stigma.

Interpersonal Processes and Attachment in Voice-Hearers.

BACKGROUND: Studies of both clinical and non-clinical voice hearers suggest that distress is rather inconsistently associated with the perceived relationship between voice and hearer. It is also not clear if their beliefs about voices are relevant. AIMS: This study investigated the links between attachment anxiety/avoidance, interpersonal aspects of the voice relationship, and distress whilst considering the impact of beliefs about voices and paranoia. METHOD: Forty-four voice-hearing participants completed a number of self-report measures tapping attachment, interpersonal processes in the voice relationship, beliefs about voices, paranoia, distress and depression. RESULTS: Attachment avoidance was related to voice intrusiveness, hearer distance and distress. Attachment anxiety was related to voice intrusiveness, hearer dependence and distress. A series of simple mediation analyses were conducted that suggest that the relationship between attachment and voice related distress may be mediated by interpersonal dynamics in the voice-hearer relationship, beliefs about voices and paranoia. CONCLUSIONS: Beliefs about voices, the hearer's relationship with their voices, and the distress voices sometimes engender appear to be meaningfully related to their attachment style. This may be important to consider in therapeutic work.

Trial by YouTube: effects of expert psychiatric witness testimony on viewers' opinions of Amber Heard and Johnny Depp.

AIMS AND METHOD: We aimed to assess whether viewing expert witness evidence regarding the mental health of Johnny Depp and Amber Heard in the 2022 court case in the USA would affect viewers' attitudes towards the mental health of the two protagonists and towards mental illness in general. After viewing excerpts of the cross-examination evidence, 38 trial-naive undergraduate students completed the Prejudice towards People with a Mental Illness (PPMI) scale. RESULTS: Following viewing, participants held more stigmatising views of the protagonists than they held about mental disorders in general. CLINICAL IMPLICATIONS: It is plausible that mass media trial coverage further stigmatises mental illness.

Investigating associations between self-compassion, self-criticism and psychotic-like experiences.

OBJECTIVES: Dimensional approaches suggest psychotic symptoms exist along a continuum, with psychotic-like experiences (PLEs) being an expression of a non-clinical psychosis phenotype. Existing research indicates self-criticism may contribute to symptom maintenance, frequency and distress, whereas self-compassion may act protectively. Associations between self-criticism, self-compassion and PLEs in the general population have received less attention. The present study sought to investigate these associations. It was hypothesised that PLE endorsement would be associated positively with self-criticism and negatively with self-compassion. DESIGN: Quantitative cross-sectional study. Data collected via an online questionnaire. METHODS: Five hundred thirty-one participants completed the Self-Compassion Scale (Short Form), the Forms of Self-Criticising/Attacking and Self-Reassuring Scale and the Transpersonal Experiences Questionnaire. Individuals with a psychosis-related diagnosis were excluded. The data were analysed using linear regression, accounting for the effects of demographic variables. RESULTS: Self-criticism subtype self-hatred was associated with PLEs. Subtype self-inadequacy was not. No association was found between self-compassion and PLEs. Educational attainment was negatively associated with PLE endorsement. CONCLUSIONS: Self-criticism, but not self-compassion, is associated with PLE endorsement, suggesting they are separate factors with different relationships to PLEs. Further research is needed to confirm the direction of the interaction. Either way, psychological interventions (where needed) could target self-criticism and may be important in assessing psychosis risk.

'It's not everybody's snapshot. It's just an insight into that world': A qualitative study of multiple perspectives towards understanding the mental health experience and addressing stigma in healthcare students through virtual reality.

Objective: The resurgence of virtual reality (VR) technologies has led to their increased use in contemporary healthcare education. One promising application is simulating the experiences of individuals with mental health conditions (MHCs) to reduce stigma among future healthcare professionals. This study set out to explore what those impacted by, or involved in, the education of healthcare students think about using VR in this way. Methods: One individual interview and five focus groups were conducted with healthcare students (n = 7), healthcare educators (n = 6), and lived experience experts (n = 5). Before sharing their perspectives, participants familiarised themselves with VR equipment and immersive materials simulating MHCs. The constant comparative method and thematic analysis were used to analyse the data. Results: Participants recognised the acceptability and utility of VR for addressing mental health stigma in healthcare students, emphasising the immersive nature of this technology. However, some participants raised concerns about the limited insight VR could provide into the experiences of patients with the same MHCs and its potential emotional impact on users. Participants recommended the incorporation of interactive, realistic environments with a person-centred focus into future VR-based stigma reduction interventions while stressing the importance of providing healthcare students with opportunities for reflection and support. Conclusions: Healthcare students, healthcare educators, and lived experience experts highlighted both advantages and barriers associated with using VR to understand the experience of patients with MHCs. Furthermore, the recommendations put forward can inform the design, content, and delivery of VR-based stigma reduction interventions in healthcare education.

Prevalence of phubbing behaviour in school and university students in Spain.

Objective: This study examined the prevalence of phubbing behavior among school and university students in Spain and analyzed the correlation of phubbing with other indicators of psychological well-being and mental health. Methods: The study sample comprised a total of 1,351 school and university students, with ages ranging from 12 to 21 years. The study used the Phubbing Scale (PS), the Compulsive Internet Use Scale (CIUS), the Rosenberg Self-Esteem Scale (RSE), and the Interpersonal Emotion Regulation Questionnaire (IERQ) for data collection. Results: The results showed evidence of phubbing among approximately half of the students. Statistically significant differences were found based on gender and educational level in the Phone Obsession subscale and the PS total score, with male students and university students scoring higher in their respective parameters. In addition, phubbing was positively correlated with problematic internet use and negatively correlated with self-esteem. Conclusion: Phubbing behavior is highly prevalent among adolescents aged 12-21 years and is positively correlated with low self-esteem and problematic internet use. Developing strategies for addressing this widespread issue at early ages, particularly within the educational context, such as schools, is crucial for implementing preventive measures. The inappropriate use of technological devices, including smartphones, in schools has the potential to negatively affect students' well-being and ability to adapt to school.

Neurobehavioral problems following low-level exposure to organophosphate pesticides: a systematic and meta-analytic review.

Meta-analysis was carried out to determine the neurotoxic effects of long-term exposure to low levels of organophosphates (OPs) in occupational settings. Concern about the effects of OPs on human health has been growing as they are increasingly used throughout the world for a variety of agricultural, industrial and domestic purposes. The neurotoxic effects of acute poisoning are well established but the possibility that low-level exposure causes ill health is controversial. It is important to get a clear answer to this question as more individuals are at risk of low-level exposure than acute poisoning. Although a number of reviews on this topic have been published in the past, authors have come to conflicting conclusions. To date, none of these reviews have attempted quantitative evaluation of study findings using meta-analysis. This paper reviews the available evidence concerning the neurotoxicity of low-level occupational exposure to OPs and goes on to report the results of a meta-analysis of 14 studies which fulfilled criteria for this type of statistical analysis (means and standard deviations of dependant variables reported). Data were assimilated from more than 1600 participants. The majority of well designed studies found a significant association between low-level exposure to OPs and impaired neurobehavioral function which is consistent, small to moderate in magnitude and concerned primarily with cognitive functions such as psychomotor speed, executive function, visuospatial ability, working and visual memory. Unresolved issues in the literature which should become the focus of further studies are highlighted and discussed.

Dimensions of positive symptoms in late versus early onset psychosis.

BACKGROUND: Casenote studies have characterized late onset schizophrenia (LOS) and related psychoses as somewhat different symptomatically from patients with an early onset schizophrenia (EOS). This study examined a range of phenomenological aspects of delusions and hallucinations as well as traditional symptom measures in both groups. METHODS: 34 LOS and 235 EOS completed the Positive and Negative Syndrome Scale, the Psychotic Symptom Rating Scales, and the Beck Depression and Anxiety inventories. Subgroups experiencing delusions were compared matching for chronological age and gender, and also when matched for chronicity and gender. RESULTS: Delusions were very common at over 80% in both groups. LOS participants with delusions exhibited greater suspiciousness/paranoia, greater belief-conviction, and reduced insight when compared with the EOS group. These findings remained when matching for chronicity of illness, but disappeared when matching for chronological age. Hallucinations were surprisingly rarer in LOS (35%) than EOS (57%), with half the LOS group reporting whispers rather than clearly audible sounds. In general, anxiety, depression, and distress were as marked in LOS and EOS. CONCLUSIONS: Similarities between EOS and LOS far outweighed the differences across a range of symptoms and measures. Greater delusional conviction, paranoia, and poorer insight in LOS were associated with the later age of onset rather than relating to chronicity of illness. As belief-conviction in LOS was not associated with increased grandiosity, disorientation, or unusualness of thought content, as it was in EOS, delusional conviction may be determined somewhat differently later in life.

Contextual memory, psychosis-proneness, and the experience of intrusive imagery.

This study tested the hypothesis that the presence and characteristics of naturally occurring involuntary imagery would be related to poorer context-dependent spatial memory and higher levels of proneness to psychotic experiences. Poorer contextual memory was also predicted to be associated with a greater sense of "nowness". Participants completed a virtual environment task that assessed contextual memory through responses that required allocentric and egocentric processing of virtual stimuli. Two questionnaires assessing predisposition to psychotic experiences were employed. Finally, participants completed an interview that required details of recent, naturally occurring involuntary images. Reports of involuntary imagery were associated with greater proneness to psychotic experiences but not with memory. In those participants who reported imagery, however, poorer memory performance was associated with more vivid and detailed intrusive imagery. Poorer contextual memory was specifically associated with a greater sense of "nowness". Possible links between contextual memory and proneness to psychosis are discussed.