White-matter abnormalities, including increases in extracellular free-water, are implicated in the pathophysiology of schizophrenia. Recent advances in diffusion magnetic resonance imaging (MRI) enable free-water levels to be indexed. However, the brain levels in patients with schizophrenia have not yet been systematically investigated. We aimed to meta-analyse white-matter free-water levels in patients with schizophrenia compared to healthy volunteers. We performed a literature search in EMBASE, MEDLINE, and PsycINFO databases. Diffusion MRI studies reporting free-water in patients with schizophrenia compared to healthy controls were included. We investigated the effect of demographic variables, illness duration, chlorpromazine equivalents of antipsychotic medication, type of scanner, and clinical symptoms severity on free-water measures. Ten studies, including five of first episode of psychosis have investigated free-water levels in schizophrenia, with significantly higher levels reported in whole-brain and specific brain regions (including corona radiata, internal capsule, superior and inferior longitudinal fasciculus, cingulum bundle, and corpus callosum). Six studies, including a total of 614 participants met the inclusion criteria for quantitative analysis. Whole-brain free-water levels were significantly higher in patients relative to healthy volunteers (Hedge’s g = 0.38, 95% confidence interval (CI) 0.07–0.69, p = 0.02). Sex moderated this effect, such that smaller effects were seen in samples with more females (z = −2.54, p < 0.05), but antipsychotic dose, illness duration and symptom severity did not. Patients with schizophrenia have increased free-water compared to healthy volunteers. Future studies are necessary to determine the pathological sources of increased free-water, and its relationship with illness duration and severity.

Introduction: The SARS-CoV-2 infection has been associated with the acute onset of mental and behavioural symptoms and psychiatric disorders. The aim of this study was to assess the prevalence of the different neuropsychiatric diagnoses in hospitalized patients with SARS-CoV-2 infection assessed by Liaison Psychiatry.Material and Methods: We performed a cross-sectional study in a hospital near Lisbon, Portugal. We reviewed the electronic health records from all inpatients with a positive SARS-CoV-2 RT-PCR test that were assessed by the Liaison Psychiatry Unit (LPU) between February and December 2020. We reviewed relevant sociodemographic and clinical data, including 15 neuropsychiatric symptoms. The prevalence of psychiatric disorders was our main outcome. We also explored differences between two groups: patients with delirium (delirium group) and patients without delirium (no delirium group).Results: We included 46 cases [Age: median = 67 years; interquartile range (IQR) = 24)], with 60.9% male individuals. Delirium was the most frequent diagnosis in our sample (43.5%), followed by major depressive disorder (21.7%). Patients with delirium were more likely to suffer from COVID-19 symptoms (delirium: 19/20, 95%; no delirium: 14/26, 53.8%; p = 0.02), and to have a longer time interval between a positive SARS-CoV-2 RT-PCR test and an evaluation by the LPU (delirium: median = 16.5 days, IQR = 16; no delirium: median = 8 days, IQR = 16.3; p = 0.045). Agitation (52.2%) and cognitive symptoms (47.8%) were the most reported neuropsychiatric symptoms.Conclusion: We found a high prevalence of delirium in our sample. This finding is in line with recent literature concerning hospitalized COVID-19 patients The higher frequency of COVID-19 symptoms found in the delirium group suggests a possible association between symptomatic SARS-CoV-2 infection and delirium onset.

It is becoming increasingly apparent that neuroinflammation plays a critical role in an array of neurological and psychiatric disorders. Recent studies have demonstrated the potential of diffusion MRI (dMRI) to characterize changes in microglial density and morphology associated with neuroinflammation, but these were conducted mostlyex vivoand/or in extreme, non-physiological animal models. Here, we build upon these studies by investigating the utility of well-established dMRI methods to detect neuroinflammationin vivoin a more clinically relevant animal model. We show that diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) indicate widespread increases in diffusivity in the brains of rats given a systemic lipopolysaccharide challenge. These diffusivity changes correlated with histologically measured changes in microglial morphology, confirming the sensitivity of dMRI to neuroinflammatory processes. This study marks a further step towards establishing a noninvasive biomarker of neuroinflammation, which would greatly facilitate early diagnosis and treatment monitoring in various neurological and psychiatric diseases.

AimsSchizophrenia is notoriously becoming one of the world's most debilitating mental disorders, affecting 1 in 100 people. There is increasing evidence that neuroinflammation plays a part in the pathogenesis of schizophrenia and other psychotic disorders; microglial activity acting as a marker for neuroinflammatory reactions in the brain. Furthermore, cannabis is an illicit substance that also evokes a similar response in the neuroimmune activity. This project explores how cannabis exposure influences an elevation in neuroinflammatory responses through TSPO levels, and whether this information can help us determine if cannabis use and increased TSPO levels can be associated with a risk factor for developing psychosis.Method55 participants (36 males and 19 females) were recruited from the community by the IRIS (Inflammatory Reaction in Schizophrenia) team at the IoPPN, King's College London, from which 34 patients with a diagnosis of schizophrenia and 21 healthy controls took part in the study. The eligible participants underwent clinical assessments and PET scanning, from which cannabis use history and PET data were collected. Participant neuroinflammatory levels are represented by [18F]DPA-714 volume and different regions of grey matter in the brain were analysed through multivariate analyses, the confounding variables being age and TSPO genotype.ResultA statistically significant association is shown between participants who have had exposure to cannabis and participants who have not had any exposure in their lifetime. The differences across the prioritised brain regions of interest were robust, the association appearing more apparent and statistically significant in the total (p = .00) and temporal grey matter (p = .00) regions of the brain. This may suggest that cannabis exposure influences the [18F]DPA-714 VT in the significant regions of interest. However, a negative association is seen with current use, the quantity of use, and the frequency of use.ConclusionThe initial findings for cannabis exposure show us a positive association with increased TSPO levels, however, limitations must be taken into account. Although we cannot readily establish that elevated TSPO levels in cannabis users can presently act as a risk factor marker for developing psychosis from this particular study, we can utilise this data to continue our research in disclosing a new system to predict the occurrence of psychosis.

IntroductionRecent studies suggest that most of schizophrenia's first-episode patients have the potential for long-term remission. Conversely, some meta-analysis estimate the actual median recovery rate to be 13.5% [1]. Relapses may contribute to the emergence of increased morbidity and treatment resistance.ObjectivesTo evaluate possible relationships between the numbers of previous admissions, years of diagnosed disease and hospitalization length.MethodsA cross-sectional retrospective study on all patients (n = 202, 150 men and 52 women) admitted at an acute inpatient unit throughout the year of 2015, diagnosed with schizophrenia (ICD-9, 295). Collection of socio-demographic data, number of previous admissions (PA), years of diagnosed disease (YDD) and hospitalization length (HL). Descriptive statistical analysis, Spearman rank correlation and Mann-Whitney U test.ResultsOverall, the sample's mean age was 44.3 years old (std 12.7), being lower in men (42.5 versus 49.7). The average of admissions was 1.2 per year. PA and YDD were significantly associated (P < 0.0001). Contrarily, there was no statistical association between the number of PA and HL (P > 0.1), as well as between YDD and HL (P > 0.1) was found.ConclusionThis study provides additional evidence for schizophrenia's early onset in men. There seems to be no association between relapses and treatment resistance, considering PA, YDD and HL as valuable soft outcomes. Future understanding of relapses’ pathophysiological mechanisms is warranted in order to explain schizophrenia's low median recovery rate.Disclosure of interestThe authors have not supplied their declaration of competing interest.