Publications by authors named "Melanie Focking"

Background: Markers of inflammation and cannabis exposure are associated with an increased risk of mental disorders. In the current study, we investigated associations between cannabis use and biomarkers of inflammation.

Methods: Utilizing a sample of 914 participants from the Avon Longitudinal Study of Parents and Children, we investigated whether interleukin-6 (IL-6), tumor necrosis factor (TNF), C-reactive protein (CRP), and soluble urokinase plasminogen activator receptor (suPAR) measured at age 24 were associated with past year daily cannabis use, less frequent cannabis use, and no past year cannabis use.

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Background: Converging evidence supports the role of Matrix Metalloproteinases (MMPs) in psychiatric disorders. Originally identified as regulators of the extracellular matrix (ECM), MMPs' functions span multiple processes, including inflammation, synaptic plasticity, neuronal migration, and blood-brain barrier maintenance. Tissue Inhibitors of Metalloproteinases (TIMPs) are major regulators of MMPs.

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Introduction: Negative symptoms impact the quality of life of individuals with psychosis and current treatment options for negative symptoms have limited effectiveness. Previous studies have demonstrated that complement and coagulation pathway protein levels are related to later psychotic experiences, psychotic disorder, and functioning. However, the prognostic relationship between complement and coagulation proteins and negative symptoms is poorly characterised.

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Article Synopsis
  • - Psychosis risk prediction in psychiatry is challenging, and a study aimed to evaluate whether a specific proteomic model could accurately predict the transition to psychosis in individuals at clinical high risk, using plasma samples from three cohorts totaling 754 participants.
  • - The study found that only 20.4% of participants developed psychosis over about 4.4 years, and the prediction model had poor accuracy (C-statistic: 0.51), suggesting that the proteomic factors didn't reliably predict outcomes.
  • - Some proteins, like Complement C8B and LRG1, showed weak associations with psychosis transition but did not reach significant levels when correcting for multiple comparisons, indicating that previous claims based on small sample sizes should
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Background: Immune dysregulation has been observed in patients with schizophrenia or first-episode psychosis, but few have examined dysregulation in those at clinical high-risk (CHR) for psychosis. The aim of this study was to examine whether the peripheral blood-based proteome was dysregulated in those with CHR. Secondly, we examined whether baseline dysregulation was related to current and future functioning and clinical symptoms.

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Article Synopsis
  • - The study explored the relationship between low-grade inflammation and mental disorders (like psychotic, depressive, and anxiety disorders) in 24-year-olds from the Avon Longitudinal Study, focusing on various inflammatory markers like IL-6 and suPAR.
  • - Out of 781 participants, those diagnosed with psychotic disorder showed significant associations with higher levels of IL-6 and suPAR, while the links to depressive disorder were weaker, and generalised anxiety disorder showed little correlation with the inflammatory markers.
  • - The findings suggest that young adults with psychotic disorders have raised inflammation markers, but the impact of childhood trauma on these associations was minimal.
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Background And Hypothesis: Treatment response to specific antipsychotic medications is difficult to predict on clinical grounds alone. The current study hypothesizes that the baseline complement pathway activity predicts the treatment response and investigates the relationship between baseline plasma biomarkers with treatment response to antipsychotic medications.

Study Design: Baseline plasma samples were collected from first episode of psychosis patients (n = 243) from a multi-center clinical trial.

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Preliminary evidence indicates beneficial effects of omega-3 polyunsaturated fatty acids (PUFAs) in early psychosis. The present study investigates the molecular mechanism of omega-3 PUFA-associated therapeutic effects in clinical high-risk (CHR) participants. Plasma samples of 126 CHR psychosis participants at baseline and 6-months follow-up were included.

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Article Synopsis
  • This study investigates how biological and clinical factors can predict functional outcomes in individuals at clinical high-risk (CHR) for psychosis, focusing on the roles of complement and coagulation pathways.
  • Researchers conducted plasma proteomics and other measurements from 158 participants in a clinical trial to develop predictive models for future functional outcomes.
  • The results showed that while the overall predictive model was not very effective, specific complement and coagulation proteins were significantly associated with both positive symptoms and functional outcomes at the 6-month mark.
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There is increasing evidence that dysregulation of polyunsaturated fatty acids (FAs) mediated membrane function plays a role in the pathophysiology of schizophrenia. Even though preclinical findings have supported the anti-inflammatory properties of omega-3 FAs on brain health, their biological roles as anti-inflammatory agents and their therapeutic role on clinical symptoms of psychosis risk are not well understood. In the current study, we investigated the relationship of erythrocyte omega-3 FAs with plasma immune markers in a clinical high risk for psychosis (CHR) sample.

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Early identification and treatment significantly improve clinical outcomes of psychotic disorders. Recent studies identified protein components of the complement and coagulation systems as key pathways implicated in psychosis. These specific protein alterations are integral to the inflammatory response and can begin years before the onset of clinical symptoms of psychotic disorder.

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Aim: Among different types of poly unsaturated fatty acids, omega-3 fatty acids (FA) play a substantial role in brain development and functioning. This review was designed to evaluate and synthesize available evidence regarding omega-3 FAs and functional outcome in the ultra-high-risk (UHR) population.

Methods: An electronic search in PubMed, EMBASE, PSYCINFO and COCHRANE search engines has been performed for all articles published until January 2019.

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Importance: Biomarkers that are predictive of outcomes in individuals at risk of psychosis would facilitate individualized prognosis and stratification strategies.

Objective: To investigate whether proteomic biomarkers may aid prediction of transition to psychotic disorder in the clinical high-risk (CHR) state and adolescent psychotic experiences (PEs) in the general population.

Design, Setting, And Participants: This diagnostic study comprised 2 case-control studies nested within the European Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI) and the Avon Longitudinal Study of Parents and Children (ALSPAC).

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Clinical and preclinical studies suggest that some of the behavioral alterations observed in schizophrenia (SZ) may be mechanistically linked to synaptic dysfunction of glutamatergic signaling. Recent genetic and proteomic studies suggest alterations of cortical glutamate receptors of the AMPA-type (AMPARs), which are the predominant ligand-gated ionic channels of fast transmission at excitatory synapses. The impact of gene and protein alterations on the electrophysiological activity of AMPARs is not known in SZ.

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Background: There is renewed focus on the complement system in the pathogenesis of schizophrenia. In addition to providing aetiological insights, consistently dysregulated complement proteins in serum or plasma may have clinical utility as biomarkers.

Methods: We performed a systematic literature review searching PubMed, Embase and PsycINFO for studies measuring complement system activity or complement protein concentrations in serum or plasma from patients with schizophrenia compared to controls.

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Aim: Over the past several decades, there has been a growing research interest in the role of inflammation in the pathogenesis of schizophrenia. This review aims to summarize evidence in support of this relationship, to discuss biological mechanisms that might explain it, and to explore the translational impact by examining evidence from trials of anti-inflammatory and immunomodulatory agents in the treatment of schizophrenia.

Methods: This narrative review of the literature summarizes evidence from observational studies, clinical trials and meta-analyses to evaluate the role of inflammation in the pathogenesis of schizophrenia and to discuss associated implications for treatment.

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Apolipoproteins, which play important roles in lipid metabolism, innate immunity and synaptic signalling, have been implicated in first episode psychosis and schizophrenia. This is the first study to investigate plasma apolipoprotein expression in children with psychotic experiences that persist into adulthood. Here, using semi-targeted proteomic analysis we compared plasma apolipoprotein expression levels in age 12 subjects who reported psychotic experiences at both age 12 and age 18 (n = 37) with age-matched subjects who only experienced psychotic experiences (PEs) at age 12 (n = 38).

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Schizophrenia is a chronic mental disorder that is still poorly understood despite decades of study. Many factors have been found to contribute to the pathogenesis, including neurodevelopmental disturbance, genetic risk, and environmental insult, but no single root cause has emerged. While evidence from twin studies suggests a strong heritable component, few individual loci have been identified in genomewide screens, suggesting a role for epigenetic effects.

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Background: The identification of early biomarkers of psychotic experiences (PEs) is of interest because early diagnosis and treatment of those at risk of future disorder is associated with improved outcomes. The current study investigated early lipidomic and coagulation pathway protein signatures of later PEs in subjects from the Avon Longitudinal Study of Parents and Children cohort.

Methods: Plasma of 115 children (12 years of age) who were first identified as experiencing PEs at 18 years of age (48 cases and 67 controls) were assessed through integrated and targeted lipidomics and semitargeted proteomics approaches.

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The complement cascade is a major component of the immune defence against infection, and there is increasing evidence for a role of dysregulated complement in major psychiatric disorders. We undertook a directed proteomic analysis of the complement signalling pathway (n = 29 proteins) using data-independent acquisition. Participants were recruited from the UK avon longitudinal study of parents and children (ALSPAC) cohort who participated in psychiatric assessment interviews at ages 12 and 18.

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The identification of early biological changes associated with the psychotic disorder (PD) is important as it may provide clues to the underlying pathophysiological mechanisms. We undertook the first proteomic profiling of blood plasma samples of children who later develop a PD. Participants were recruited from the UK Avon Longitudinal Study of Parents and Children (ALSPAC) cohort who also participated in psychiatric assessment interviews at age 18.

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Prenatal iron deficiency (pID) has been described to increase the risk for neurodevelopmental disorders such as autism and schizophrenia; however, the precise molecular mechanisms are still unknown. Here, we utilized high-throughput MS to examine the proteomic effects of pID in adulthood on the rat frontal cortex area (FCA). In addition, the FCA proteome was examined in adulthood following risperidone treatment in adolescence to see if these effects could be prevented.

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Recent evidence supports an association between systemic abnormalities and the pathology of psychotic disorders which has led to the search for peripheral blood-based biomarkers. Areas covered: Here, we summarize blood biomarker findings in schizophrenia from the literature identified by two methods currently driving biomarker discovery in the human proteome; mass spectrometry and multiplex immunoassay. From a total of 14 studies in the serum or plasma of drug-free schizophrenia patients; 47 proteins were found to be significantly altered twice or more, in the same direction.

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