Binocular 3D Motion Perception as Bayesian Inference

The human visual system encodes monocular motion and binocular disparity input before it is integrated into a single 3D percept. Here we propose a geometric-statistical model of human 3D motion perception that solves the aperture problem in 3D by assuming that (i) velocity constraints arise from inverse projection of local 2D velocity constraints in a binocular viewing geometry, (ii) noise from monocular motion and binocular disparity processing is independent, and (iii) slower motions are more likely to occur than faster ones. In two experiments we found that instantiation of this Bayesian model can explain perceived 3D line motion direction under ambiguity and uncertainty

Health-risk behaviours among people with severe mental ill health: understanding modifiable risk in the Closing the Gap Health Study

© 2023 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/BACKGROUND: People with severe mental ill health (SMI) experience some of the largest health inequalities of any sector within society. For these inequalities to be reduced, an understanding of the behavioural determinants of health in this population is needed. AIMS: Utilising data from the Closing the Gap Health Study, we aimed to assess the extent to which people with SMI report health-risk factors and behaviours, their interest in modifying them, and the factors associated with being motivated to modify these behaviours. METHOD: Adult (≥18 years old) participants were recruited via primary and secondary care in the English National Health Service. To be eligible, participants needed to have a documented diagnosis of schizophrenia, psychotic disorders or bipolar disorder. Data were collected by survey on demographics, general physical health, diet, physical activity, alcohol, smoking and body mass index. RESULTS: Between April 2016 and March 2020, n = 9914 participants were recruited. Among people with SMI, high rates of obesity (37.5%), infrequent physical activity (62.0%), not meeting current guidelines (≥5) for the consumption of fruit and vegetables (85.0%) and smoking (42.2%) were observed. However, most participants were motivated to reduce health-risk behaviours. Perceiving the importance of health-promoting behaviours, being of poorer general health and being female were significantly associated with being motivated to modify health-risk behaviours. CONCLUSIONS: Despite experiencing poor physical and mental health outcomes compared with the general population, and contrary to popular misconceptions, people with SMI perceive health as important and are motivated to make behavioural changes to improve health.Peer reviewe

Challenges and solutions to nicotine replacement therapy access: observations from SCIMITAR+

Background Given, smoking results in poor physical and mental health, reducing tobacco harm is of high importance. Recommendations published by National Institute for Health and Care Excellence to reduce smoking harms included provision of support, use of nicotine containing products and commissioning of smoking cessation services. Aims This report explores the difficulties in obtaining such support, as observed in a recently conducted randomised controlled trial in patients with severe mental ill health, and outlines suggestions to improve facilitation of provision. Methods Data collected during the Smoking Cessation Intervention for severe Mental Ill Health Trial (SCIMITAR+) trial, was reviewed to identify the difficulties experienced, across the trial, with regards to access and provision of NRT. Actions taken to facilitate access and provision of NRT were collated to outline how provision could be better facilitated. Results Access to nicotine replacements therapy (NRT) varied across study settings and in some instances proved impossible for patients to access. Difficulty in access was irrespective of a diagnosis of severe mental ill health. Where NRT was provided, this was not always provided in accordance with NICE guidelines. Conclusions Availability of smoking cessation support, and NRT provision would benefit from being made clearer, simpler and more easily accessible so as to enhance smoking cessation rates

Smoking cessation in severe mental illness: : combined long-term quit rates from the UK SCIMITAR trials programme

Simon Gilbody, Emily Peckham, Della Bailey, Catherine Arundel, Paul Heron, , , , and members of the SCIMITAR+ collaborative

High-Potency Cannabis, Mental Health and Substance Use in Adolescence:Results from a UK General Population Sample

Importance Cannabis use is consistently linked to poorer mental health outcomes, and there is evidence that use of higher-potency cannabis increases these risks. To date, no studies have described the association between cannabis potency and concurrent mental health in a general population sample or addressed confounding using longitudinal data. Objective To explore the association between cannabis potency and substance use and mental health outcomes, accounting for preceding mental health and frequency of cannabis use. Design, Setting, and Participants This cohort study used data from the Avon Longitudinal Study of Parents and Children, a UK birth cohort of participants born between April 1, 1991, and December 31, 1992. Present data on outcomes and exposures were collected between June 2015 and October 2017 from 1087 participants at 24 years of age who reported recent cannabis use. Exposures Self-reported type of cannabis most commonly used in the past year, coded to a binary exposure of use of high-potency cannabis or lower-potency cannabis. Main Outcomes and Measures Outcomes were reported frequency of cannabis use, reported cannabis use problems, recent use of other illicit drugs, tobacco dependence, alcohol use disorder, depression, generalized anxiety disorder, and psychotic-like experiences. The study used secondary data; consequently, the hypotheses were formulated after data collection. Results Past-year cannabis use was reported by 1087 participants (580 women; mean [SD] age at onset of cannabis use, 16.7 [3.0] years). Of these, 141 participants (13.0%) reported the use of high-potency cannabis. Use of high-potency cannabis was associated with increased frequency of cannabis use (adjusted odds ratio [AOR], 4.38; 95% CI, 2.89-6.63), cannabis problems (AOR, 4.08; 95% CI, 1.41-11.81), and increased likelihood of anxiety disorder (AOR, 1.92; 95% CI, 1.11-3.32). Adjustment for frequency of cannabis use attenuated the association with psychotic experiences (AOR 1.29; 95% CI, 0.67-2.50), tobacco dependence (AOR, 1.42; 95% CI, 0.89-2.27), and other illicit drug use (AOR, 1.29; 95% CI, 0.77-2.17). There was no evidence of association between the use of high-potency cannabis and alcohol use disorder or depression. Conclusions and Relevance To our knowledge, this study provides the first general population evidence suggesting that the use of high-potency cannabis is associated with mental health and addiction. Limiting the availability of high-potency cannabis may be associated with a reduction in the number of individuals who develop cannabis use disorders, the prevention of cannabis use from escalating to a regular behavior, and a reduction in the risk of mental health disorders

Association of Combined Patterns of Tobacco and Cannabis Use in Adolescence With Psychotic Experiences

IMPORTANCE: There is concern about potentially causal effects of tobacco use on psychosis, but epidemiological studies have been less robust in attempts to minimize effects of confounding than studies of cannabis use have been. Objectives: To examine the association of patterns of cigarette and cannabis use with preceding and subsequent psychotic experiences, and to compare effects of confounding across these patterns. Design, Setting, and PARTICIPANTS: This cohort study used data from the Avon Longitudinal Study of Parents and Children, which initially consisted of 14 062 children. Data were collected periodically from September 6, 1990, with collection ongoing, and analyzed from August 8, 2016, through June 14, 2017. Cigarette and cannabis use data were summarized using longitudinal latent class analysis to identify longitudinal classes of substance use. Associations between classes and psychotic experiences at age 18 years were assessed. EXPOSURES: Depending on the analysis model, exposures were longitudinal classes of substance use or psychotic experiences at age 12 years. MAIN OUTCOMES AND MEASURES: Logistic regression was used to examine the associations between substance use longitudinal classes and subsequent onset of psychotic experiences. Results: Longitudinal classes were derived using 5300 participants (56.1% female) who had at least 3 measures of cigarette and cannabis use from ages 14 to 19 years. Prior to adjusting for a range of potential confounders, there was strong evidence that early-onset cigarette-only use (4.3%), early-onset cannabis use (3.2%), and late-onset cannabis use (11.9%) (but not later-onset cigarette-only use [14.8%]) latent classes were associated with increased psychotic experiences compared with nonusers (65.9%) (omnibus P < .001). After adjusting for confounders, the association for early-onset cigarette-only use attenuated substantially (unadjusted odds ratio [OR], 3.03; 95% CI, 1.13-8.14; adjusted OR, 1.78; 95% CI, 0.54-5.88), whereas those for early-onset cannabis use (adjusted OR, 3.70; 95% CI, 1.66-8.25) and late-onset cannabis use (adjusted OR, 2.97; 95% CI, 1.63-5.40) remained consistent. CONCLUSIONS AND RELEVANCE: In this study, our findings indicate that while individuals who use cannabis or cigarettes during adolescence have an increased risk of subsequent psychotic experiences, epidemiological evidence is substantively more robust for cannabis use than it is for tobacco use

Exploring Access to Mental Health and Primary Care Services for People With Severe Mental Illness During the COVID-19 Restrictions

Aims: To explore: how satisfied people with severe mental illness (SMI) are with the support received during the pandemic; understand any difficulties encountered when accessing both mental health and primary care services; consider ways to mitigate these difficulties; and assess the perceived need for future support from mental health services. Materials and Methods: A representative sample was drawn from a large transdiagnostic clinical cohort of people with SMI, which was recruited between April 2016 and March 2020. The sample was re-surveyed a few months after the beginning of the restrictions. Descriptive frequency statistics were used to analyze the quantitative data. The free text responses were analyzed thematically. Results: 367 participants responded to the survey. Two thirds were receiving support from mental health services with the rest supported in primary care or self-managing. A quarter thought they would need more mental health support in the coming year. Half had needed to used community mental health services during the pandemic and the majority had been able to get support. A minority reported that their mental health had deteriorated but they had either not got the supported they wanted or had not sought help. The biggest service change was the reduction in face-to-face appointments and increasing use of phone and video call support. Nearly half of those using mental health services found this change acceptable or even preferred it. However, acceptability was influenced by several factors, and participants were more likely to report that they had received all the support they needed, when seen in person. Discussion: Although most participants were satisfied with the mental health support they had received, a minority were not. This, couple with findings on future need for mental health support has implications for post pandemic demand on services. Remote care has brought benefits but also risks that it could increase inequalities in access to services

Loneliness among people with severe mental illness during the COVID-19 pandemic : Results from a linked UK population cohort study

AIM/GOAL/PURPOSE: Population surveys underrepresent people with severe mental ill health. This paper aims to use multiple regression analyses to explore perceived social support, loneliness and factor associations from self-report survey data collected during the Covid-19 pandemic in a sample of individuals with severe mental ill health. DESIGN/METHODOLOGY/APPROACH: We sampled an already existing cohort of people with severe mental ill health. Researchers contacted participants by phone or by post to invite them to take part in a survey about how the pandemic restrictions had impacted health, Covid-19 experiences, perceived social support, employment and loneliness. Loneliness was measured by the three item UCLA loneliness scale. FINDINGS: In the pandemic sub-cohort, 367 adults with a severe mental ill health diagnosis completed a remote survey. 29-34% of participants reported being lonely. Loneliness was associated with being younger in age (adjusted OR = -.98, p = .02), living alone (adjusted OR = 2.04, p = .01), high levels of social and economic deprivation (adjusted OR = 2.49, p = .04), and lower perceived social support (B = -5.86, p < .001). Living alone was associated with lower perceived social support. Being lonely was associated with a self-reported deterioration in mental health during the pandemic (adjusted OR = 3.46, 95%CI 2.03-5.91). PRACTICAL IMPLICATIONS: Intervention strategies to tackle loneliness in the severe mental ill health population are needed. Further research is needed to follow-up the severe mental ill health population after pandemic restrictions are lifted to understand perceived social support and loneliness trends. ORIGINALITY: Loneliness was a substantial problem for the severe mental ill health population before the Covid-19 pandemic but there is limited evidence to understand perceived social support and loneliness trends during the pandemic

A Year Into the Pandemic : The Diversity of Experience Amongst People With Severe Mental Ill Health

Background: The COVID-19 pandemic has amplified pre-existing health inequalities and people with severe mental ill health (SMI) are one of the groups at greatest risk. In this study, we explored the effects of the pandemic and pandemic restrictions on people with SMI during the first year of the pandemic. Methods: We conducted a longitudinal study in a sample of people with SMI. The inception survey was carried out between July and December 2020. Participants were then re-surveyed between January and March 2021. People were contacted by telephone and invited to take part in the study over the phone, online or by postal questionnaire. Across both waves we asked participants about their physical and mental health, health risk behaviors, well-being, loneliness, and employment status. Results: Three hundred and sixty-seven people with SMI completed the inception survey and 249 people completed the follow up. Whilst some people reported no change in their physical (77, 31%) or mental health (60, 24%) over the course of the pandemic 53 (21%) reported a continuing decline in physical health and 52 (21%) reported a continuing decline in mental health. Participants who maintained a daily routine or reported no decline in physical health were found to be associated with no deterioration in mental health (Daily routine OR 2.27, 95% CI 1.11-4.64; no reported physical health decline OR 0.54, 95% CI 0.17-0.70). Participants were less likely to be occupationally active in the first phase of the pandemic compared to before the pandemic and in the second phase of the pandemic. However, there was no one single experience of people with SMI and similar to studies in the general populations a range of different scenarios was experienced. Conclusions: We observed a series of factors that might amplify pre-existing health inequalities. Health systems should be mindful of this, and should redouble efforts to set in place changes to practice and policy, which can mitigate these inequalities. Examples might include; raising awareness of the importance of ensuring that people with SMI receive an annual physical health check and supporting people to maintain a daily routine

The role of animal ownership for people with severe mental illness during the Covid-19 pandemic: a mixed-method study investigating links with health and loneliness

Research has reported the benefits of companion animals for people with severe mental illness (SMI). However, this evidence base is fragmented and unclear. The COVID-19 pandemic presents an opportunity to explore the role of companion animals in the context of social distancing and isolation measures for people with SMI. Therefore, we aimed to investigate the links between mental and physical health and animal ownership in people with SMI and to explore animal owners’ perceptions related to human–animal interactions during the pandemic restrictions. A survey was conducted with a previously assembled cohort of individuals with SMI in the UK. The survey included previously validated and new bespoke items measuring demographics, and outcomes related to mental and physical health, and human–animal interactions. The survey also included a question inviting free-text responses, allowing participants to describe any experiences of their human–animal relationships during the pandemic. Of 315 participants who consented to participate, 249 (79%) completed the survey. Of these, 115 (46.2%) had at least one companion animal. Regression analyses indicated that animal ownership was not significantly associated with well-being and loneliness. However, animal ownership was associated with a self-reported decline in mental health (b = 0.640, 95% CI [0.102–1.231], p = 0.025), but no self-reported change in physical health. Thematic analysis identified two main themes relating to the positive and negative impact of animal ownership during pandemic restrictions. Animal ownership appeared to be linked to self-reported mental health decline in people with SMI during the second wave of the pandemic in the UK. However, the thematic analysis also highlighted the perceived benefit of animal ownership during this time. Further targeted investigation of the role of human–animal relationships and the perceived human–animal bond for human health is warranted