The effect of cannabis use and cognitive reserve on age at onset and psychosis outcomes in first-episode schizophrenia

Cannabis use is associated with a younger age at onset of psychosis, an indicator of poor prognosis, but better cognitive function, a positive prognostic indicator. We aimed to clarify the role of age at onset and cognition on outcomes in cannabis users with first-episode schizophrenia as well as the effect of cannabis dose and cessation of use

Cohomology for infinitesimal unipotent algebraic and quantum groups

In this paper we study the structure of cohomology spaces for the Frobenius kernels of unipotent and parabolic algebraic group schemes and of their quantum analogs. Given a simple algebraic group $G$, a parabolic subgroup $P_J$, and its unipotent radical $U_J$, we determine the ring structure of the cohomology ring $H^\bullet((U_J)_1,k)$. We also obtain new results on computing $H^\bullet((P_J)_1,L(\lambda))$ as an $L_J$-module where $L(\lambda)$ is a simple $G$-module with high weight $\lambda$ in the closure of the bottom $p$-alcove. Finally, we provide generalizations of all our results to the quantum situation.Comment: 18 pages. Some proofs streamlined over previous version. Additional details added to some proofs in Section

Are socioenvironmental factors associated with psychotic symptoms in people with first-episode psychosis? A cross-sectional study of a West London clinical sample.

OBJECTIVES: To determine whether neighbourhood-level socioenvironmental factors including deprivation and inequality predict variance in psychotic symptoms after controlling for individual-level demographics. DESIGN: A cross-sectional design was employed. SETTING: Data were originally collected from secondary care services within the UK boroughs of Ealing, Hammersmith and Fulham, Wandsworth, Kingston, Richmond, Merton, Sutton and Hounslow as part of the West London First-Episode Psychosis study. PARTICIPANTS: Complete case analyses were undertaken on 319 participants who met the following inclusion criteria: aged 16 years or over, resident in the study's catchment area, experiencing a first psychotic episode, with fewer than 12 weeks' exposure to antipsychotic medication and sufficient command of English to facilitate assessment. OUTCOME MEASURES: Symptom dimension scores, derived from principal component analyses of the Scale for the Assessment of Positive Symptoms and Scale for the Assessment of Negative Symptoms, were regressed on neighbourhood-level predictors, including population density, income deprivation, income inequality, social fragmentation, social cohesion, ethnic density and ethnic fragmentation, using multilevel regression. While age, gender and socioeconomic status were included as individual-level covariates, data on participant ethnicity were not available. RESULTS: Higher income inequality was associated with lower negative symptom scores (coefficient=-1.66, 95% CI -2.86 to -0.46, p<0.01) and higher levels of ethnic segregation were associated with lower positive symptom scores (coefficient=-2.32, 95% CI -4.17 to -0.48, p=0.01) after adjustment for covariates. CONCLUSIONS: These findings provide further evidence that particular characteristics of the environment may be linked to specific symptom clusters in psychosis. Longitudinal studies are required to begin to tease apart the underlying mechanisms involved as well as the causal direction of such associations

A window into the brain: an in vivo study of the retina in schizophrenia using optical coherence tomography.

Retinal nerve fibre layer (RNFL) thickness and macular volume (MV) can be measured in vivo using optical coherence tomography (OCT) providing a "window into the brain". RNFL and MV are promising biomarkers in neurological diseases. This study explores the potential of RNFL and MV to detect axonal abnormalities in vivo in schizophrenia and their correlations with clinical features. OCT was performed in 49 patients (38 schizophrenia, 11 schizoaffective disorder) and 40 healthy controls matched for age and gender. Group comparisons were made between whole retina and quadrant RNFL thickness and MV using multi-level analyses. In patients, associations were sought between RNFL and MV with symptom severity (positive/negative). Patients and controls had similar whole retina RNFL thickness (p=0.86) and MV (p=0.64), but RNFL in the right nasal quadrant of the schizoaffective group was thinner than in the schizophrenia group (p=0.02). In patients, positive symptom severity was associated with smaller MV (right β=-0.54, p=0.02; left β=-0.49, p=0.04). Normal MV and RNFL thickness suggests unmyelinated axons in patients with schizophrenia/schizoaffective disorder remain unaffected. Longitudinal studies using higher resolution OCT will clarify whether progressive RNFL and MV changes occur and whether they can be used as state or trait markers in schizophrenia

The component structure of the scales for the assessment of positive and negative symptoms in first-episode psychosis and its dependence on variations in analytic methods.

A secondary analysis was undertaken on Scales for the Assessment of Positive and Negative Symptoms (SAPS/SANS) data from 345 first-episode psychosis (FEP) patients gathered in the West London FEP study. The purpose of this study was to determine: (i) the component structure of these measures in FEP (primary analyses), and (ii) the dependence of any findings in these primary analyses on variations in analytic methods. Symptom ratings were exposed to data reduction methods and the effects of the following manipulations ascertained: (i) level of analysis (individual symptom vs. global symptom severity ratings), (ii) extraction method (principal component vs. exploratory factor analysis) and (iii) retention method (scree test vs. Kaiser criterion). Whilst global ratings level analysis rendered the classic triad of psychotic syndromes (positive, negative and disorganisation), symptom level analyses revealed a hierarchical structure, with 11 first-order components subsumed by three second-order components, which also mapped on to this syndrome triad. These results were robust across data reduction but not component retention methods, suggesting that discrepancies in the literature regarding the component structure of the SAPS/SANS partly reflect the level of analysis and component retention method used. Further, they support a hierarchical symptom model, the implications of which are discussed

From evidence-base to practice: implementation of the Nurse Family Partnership programme in England

The aims of this article are to highlight the issues that are relevant to the implementation of a rigorously evidence-based programme of support, the Nurse Family Partnership programme, into a national system of care. Methods used are semi-structured interviews with families in receipt of the programme in the first 10 sites, with the nursing staff, with members of the central team guiding the initiative and with other professionals. Analyses of data collected during programme delivery evaluate fidelity of delivery. The results indicate that the programme is perceived in a positive light and take-up is high, with delivery close to the stated US objectives. Issues pertaining to sustainability are highlighted - in particular, local concerns about cost set against long-term rather than immediate gains. However, local investment is predominantly strong, with creative methods being planned for the future. Overall, the study shows that within an NHS system of care it is possible to deliver a targeted evidence-based programme