29 research outputs found

    Early sustained recovery following first episode psychosis:Evidence from the AESOP10 follow-up study

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    Objective: To describe the characteristics of individuals with early sustained recovery following first episode psychosis. Methods: Individuals with a first episode psychosis were followed-up for ten years. Comparisons were made between those with Early Sustained Recovery and those with Other Course types. Results: Of 345 individuals, n=43 (12.5%) had Early Sustained Recovery. They were more likely than those with Other Course types to be female (OR=2.45; 95% CI: 1.25-4.81); employed (OR=2.39; 95% CI: 1.22-4.69); in a relationship (OR=2.68; 95% CI: 1.35-5.32); have a short DUP (OR=2.86; 95% CI: 1.37-5.88); and have a diagnosis other than schizophrenia, particularly mania (OR=6.39; 95% CI: 2.52-16.18) or brief psychosis (OR=3.64; 95% CI: 1.10-12.10). Conclusions: Sustained recovery from first episode psychosis occurs in a minority. (c) 2018 Elsevier B.V. All rights reserved

    Temporal Limits of Visual Motion Processing: Psychophysics and Neurophysiology

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    Under optimal conditions, just 3–6 ms of visual stimulation suffices for humans to see motion. Motion perception on this timescale implies that the visual system under these conditions reliably encodes, transmits, and processes neural signals with near-millisecond precision. Motivated by in vitro evidence for high temporal precision of motion signals in the primate retina, we investigated how neuronal and perceptual limits of motion encoding relate. Specifically, we examined the correspondence between the time scale at which cat retinal ganglion cells in vivo represent motion information and temporal thresholds for human motion discrimination. The timescale for motion encoding by ganglion cells ranged from 4.6 to 91 ms, and depended non-linearly on temporal frequency, but not on contrast. Human psychophysics revealed that minimal stimulus durations required for perceiving motion direction were similarly brief, 5.6–65 ms, and similarly depended on temporal frequency but, above ~10%, not on contrast. Notably, physiological and psychophysical measurements corresponded closely throughout (r = 0.99), despite more than a 20-fold variation in both human thresholds and optimal timescales for motion encoding in the retina. The match in absolute values of the neurophysiological and psychophysical data may be taken to indicate that from the lateral geniculate nucleus (LGN) through to the level of perception little temporal precision is lost. However, we also show that integrating responses from multiple neurons can improve temporal resolution, and this potential trade-off between spatial and temporal resolution would allow for loss of temporal resolution after the LGN. While the extent of neuronal integration cannot be determined from either our human sychophysical or neurophysiological experiments and its contribution to the measured temporal resolution is unknown, our results demonstrate a striking similarity in stimulus dependence between the temporal fidelity established in the retina and the temporal limits of human motion discrimination

    Bilateral hippocampal increase following first-episode psychosis is associated with good clinical, functional and cognitive outcomes

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    Background - Hippocampal pathology has been proposed to underlie clinical, functional and cognitive impairments in schizophrenia. The hippocampus is a highly plastic brain region; examining change in volume, or change bilaterally, over time, can advance understanding of the substrate of recovery in psychosis. Method - Magnetic resonance imaging and outcome data were collected at baseline and 6-year follow-up in 42 first-episode psychosis subjects and 32 matched controls, to investigate whether poorer outcomes are associated with loss of global matter and hippocampal volumes. Bilateral hippocampal increase (BHI) over time, as a marker of hippocampal plasticity was hypothesized to be associated with better outcomes. Regression analyses were performed on: (i) clinical and functional outcomes with grey matter volume change and BHI as predictor variables; and (ii) cognitive outcome with BHI as predictor. Results - BHI was present in 29% of psychosis participants. There was no significant grey matter loss over time in either patient or control groups. Less severe illness course and lesser symptom severity were associated with BHI, but not with grey matter change. Employment and global function were associated with BHI and with less grey matter loss. Superior delayed verbal recall was also associated with BHI. Conclusions - BHI occurs in a minority of patients following their first psychotic episode and is associated with good outcome across clinical, functional and cognitive domains

    Differing patterns of brain structural abnormalities between black and white patients with their first episode of psychosis

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    BACKGROUND: African-Caribbean and black African people living in the UK are reported to have a higher incidence of diagnosed psychosis compared with white British people. It has been argued that this may be a consequence of misdiagnosis. If this is true they might be less likely to show the patterns of structural brain abnormalities reported in white British patients. The aim of this study therefore was to investigate whether there are differences in the prevalence of structural brain abnormalities in white and black first-episode psychosis patients.MethodWe obtained dual-echo (proton density/T2-weighted) images from a sample of 75 first-episode psychosis patients and 68 healthy controls. We used high resolution magnetic resonance imaging and voxel-based methods of image analysis. Two separate analyses were conducted: (1) 34 white British patients were compared with 33 white British controls; (2) 41 African-Caribbean and black African patients were compared with 35 African-Caribbean and black African controls. RESULTS: White British patients and African-Caribbean/black African patients had ventricular enlargement and increased lenticular nucleus volume compared with their respective ethnic controls. The African-Caribbean/black African patients also showed reduced global grey matter and increased lingual gyrus grey-matter volume. The white British patients had no regional or global grey-matter loss compared with their normal ethnic counterparts but showed increased grey matter in the left superior temporal lobe and right parahippocampal gyrus. CONCLUSIONS: We found no evidence in support of our hypothesis. Indeed, the finding of reduced global grey-matter volume in the African-Caribbean/black African patients but not in the white British patients was contrary to our prediction

    Neuropsychological functioning in first-episode schizophrenia

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    Background - Identifying neurocognitive subtypes in schizophrenia may help establish neurobiologically meaningful subtypes of the disorder, but is frequently confounded by differences in intellectual function between individuals with schizophrenia and controls. Aims - To examine neuropsychological performance in individuals with epidemiologically based, first-onset schizophrenia and intellectually matched controls. Method - Using standard IQ and reading tests, we examined the proportions of 101 people with epidemiologically derived, first-onset schizophrenia/schizoaffective disorder and 317 community controls, falling into three a priori defined intellectual categories: ‘stable good’, ‘deteriorated poor’ and ‘stable poor’. Neuropsychological function was compared between intellectually matched participants with schizophrenia and control subgroups. Results - Multiple deficits in executive function, processing speed and verbal memory, but not visual/spatial perception/memory, were detected in all participant groups with schizophrenia compared with controls. The average effect size across the affected domains ranged from small to medium to large in the stable good, deteriorated poor and stable poor subgroups of participants with schizophrenia, respectively. Conclusions - Compared with intellectually matched controls, people with epidemiologically derived, first-onset schizophrenia/schizoaffective disorder show multiple deficits in executive function, processing speed and verbal memory

    Clinical and social determinants of duration of untreated psychosis in the AESOP first-episode psychosis study

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    Background : Despite considerable research investigating the relationship between a long duration of untreated psychosis (DUP) and outcomes, there has been much less considering predictors of a long DUP. Aims : To investigate the clinical and social determinants of DUP in a large sample of patients with a first episode of psychosis. Method : All patients with a first episode of psychosis who made contact with psychiatric services over a 2-year period and were living in defined catchment areas in London and Nottingham, UK were included in the ÆSOP study. Data relating to clinical and social variables and to DUP were collected from patients, relatives and case notes. Results : An insidious mode of onset was associated with a substantially longer DUP compared with an acute onset, independent of other factors. Unemployment had a similar, if less strong, effect. Conversely, family involvement in help-seeking was independently associated with a shorter duration. There was weak evidence that durations were longer in London than in Nottingham. Conclusions : These findings suggest that DUP is influenced both by aspects of the early clinical course and by the social context
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