Dysglycaemia, Inflammation and Psychosis: Findings From the UK ALSPAC Birth Cohort

Altered gut microbiota and systemic immunity in Chinese patients with schizophrenia comorbid with metabolic syndrome

BACKGROUND

Metabolic syndrome (MetS) is highly prevalent in individuals with schizophrenia (SZ), leading to negative consequences like premature mortality. Gut dysbiosis, which refers to an imbalance of the microbiota, and chronic inflammation are associated with both SZ and MetS. However, the relationship between gut dysbiosis, host immunological dysfunction, and SZ comorbid with MetS (SZ-MetS) remains unclear. This study aims to explore alterations in gut microbiota and their correlation with immune dysfunction in SZ-MetS, offering new insights into its pathogenesis.

METHODS AND RESULTS

We enrolled 114 Chinese patients with SZ-MetS and 111 age-matched healthy controls from Zhejiang, China, to investigate fecal microbiota using Illumina MiSeq sequencing targeting 16 S rRNA gene V3-V4 hypervariable regions. Host immune responses were assessed using the Bio-Plex Pro Human Cytokine 27-Plex Assay to examine cytokine profiles. In SZ-MetS, we observed decreased bacterial α-diversity and significant differences in β-diversity. LEfSe analysis identified enriched acetate-producing genera (Megamonas and Lactobacillus), and decreased butyrate-producing bacteria (Subdoligranulum, and Faecalibacterium) in SZ-MetS. These altered genera correlated with body mass index, the severity of symptoms (as measured by the Scale for Assessment of Positive Symptoms and Scale for Assessment of Negative Symptoms), and triglyceride levels. Altered bacterial metabolic pathways related to lipopolysaccharide biosynthesis, lipid metabolism, and various amino acid metabolism were also found. Additionally, SZ-MetS exhibited immunological dysfunction with increased pro-inflammatory cytokines, which correlated with the differential genera.

CONCLUSION

These findings suggested that gut microbiota dysbiosis and immune dysfunction play a vital role in SZ-MetS development, highlighting potential therapeutic approaches targeting the gut microbiota. While these therapies show promise, further mechanistic studies are needed to fully understand their efficacy and safety before clinical implementation.

Metabolic disturbances are risk factors for readmission to psychiatric hospitals in non-smokers but not in smokers: results from a Swiss psychiatric cohort and in first-episode psychosis patients

Background

Psychiatric patients are at high risk of readmission, and a high body mass index has previously been shown as a risk factor. We sought to replicate this finding and 1) to prospectively assess the association of metabolic syndrome and its five components with readmission in psychiatric hospitals and 2) to identify other clinical and sociodemographic predictors of readmission.

Methods

Between 2007 and 2019, data on 16727 admissions of 7786 adult and elderly patients admitted to the Department of Psychiatry of the Lausanne University Hospital, were collected. Metabolic syndrome was defined according to the International Diabetes Federation definition. Cox frailty models were used to investigate the associations between readmission and metabolic disturbances.

Results

A total of 2697 (35%) patients were readmitted to our psychiatric hospital. Novel risk factors for readmission in non-smokers were identified, including being overweight (HR=1.26; 95%CI=[1.05; 1.51]) or obese (HR=1.33; 95%CI=[1.08; 1.62]), displaying hypertriglyceridemia (HR=1.21; 95%CI=[1.04; 1.40]) and metabolic syndrome (HR=1.26; 95%CI=[1.02; 1.55]). Central obesity and hyperglycemia increased the risk of readmission when considering the Health of the Nation Outcome Scales variable. In first-episode psychosis patients, obesity (HR=2.23; 95%CI=[1.14; 4.30]) and high-density lipoprotein hypocholesterolemia (HR=1.90; 95%CI=[1.14; 3.20]) doubled the risk of readmission.

Conclusion

The observed interaction between smoking and metabolic variables are compatible with a ceiling effect; metabolic variables increase the risk of readmission in non-smokers but not in smokers who are already at higher risk. Future studies should determine whether better metabolic monitoring and treatment can reduce readmission risk.

Associations between plasma inflammatory markers and psychotic disorder, depressive disorder and generalised anxiety disorder in early adulthood: A nested case-control study

BACKGROUND

Low-grade inflammation may occur in association with several mental disorders of early adulthood, though associations with markers of chronic inflammation such as soluble urokinase plasminogen activator receptor (suPAR) are less well-established. We aimed to examine associations between acute and chronic inflammatory markers and mental disorders, as well as psychiatric co-morbidity, in young adults aged 24 years in the Avon Longitudinal Study of Parents and Children.

METHODS

Included were 781 participants (of 4019 who attended at age 24 years) who completed psychiatric assessments and provided plasma samples. Of these, 377 met criteria for psychotic disorder, depressive disorder or generalised anxiety disorder and 404 did not. Plasma concentrations of IFN-γ, IL-6, IL-8, IL-10, TNF-α, CRP, sVCAM1, sICAM1, suPAR and alpha-2-macroglobulin were measured using immunoassays. Logistic regression compared standardised inflammatory marker levels in cases and controls. Negative binomial regression evaluated associations between inflammatory markers and co-morbidity (number of mental disorders). Models were adjusted for sex, body mass index, cigarette smoking, cannabis use and employment status, then additionally for childhood trauma.

RESULTS

For psychotic disorder, there was evidence for associations with IL-6 (odds ratio[OR] 1.68, 95 %CI 1.20-2.34) and suPAR (OR 1.74, 95 %CI 1.17-2.58). There was weaker evidence for an association between suPAR and depressive disorder (OR 1.31, 95 %CI 1.05-1.62). There was little evidence for associations between inflammatory markers and generalised anxiety disorder. There was weak evidence for an association between suPAR and co-morbidity (β 0.10, 95 %CI 0.01-0.19). There was little evidence for additional confounding by childhood trauma.

CONCLUSIONS

There was evidence that 24-year-olds with psychotic disorder had raised plasma IL-6 and suPAR concentrations compared to controls. These findings have implications regarding the role of inflammation in mental disorders in early adulthood.

Psychotic-like experiences are associated with physical disorders in general population: A cross-sectional study from the NESARC II

BACKGROUND

Psychotic-like experiences (PLEs) constitute subthreshold symptoms of psychotic disorders, and belong to five distinct dimensions: Positive, Negative, Depressive, Mania and Disorganization. PLEs are associated with various psychiatric disorders. However, few studies examined their association with physical disorders.

OBJECTIVE

Our aims were (1) to assess the associations between various physical disorders and PLEs in a U.S. representative sample, and (2) to examine these associations according to the five dimensions of PLEs.

METHOD

We used data from the wave II (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC-II), a large national sample representative of the US population (N = 34,653). Participants were assessed with the Alcohol Use Disorder and Associated Disabilities Interview Schedule 4. Twenty-two PLEs were examined. Lifetime prevalence and adjusted Odds-Ratio (aOR) reflecting the association of sixteen physical disorders (including notably metabolic conditions and heart diseases) with PLEs were calculated.

RESULTS

All studied physical disorders were associated with the presence of PLEs. Particularly the presence of any physical condition, any heart disease and diabetes were more frequent in participants with at least one PLE compared with the group without any PLE (aOR = 1.74, 95% CI = 1.62-1.87, aOR = 1.44, 95% CI = 1.33-1.55 and aOR = 1.38, 95% CI = 1.24-1.54, respectively). Almost all physical disorders were associated with the five dimensions of PLEs.

CONCLUSIONS

PLEs were associated with a large range of physical disorders, with a gradual dose effect. To assess PLEs in the general population could help with the screening of subjects with physical disorders.

Predicting treatment resistance from first-episode psychosis using routinely collected clinical information

Around a quarter of people who experience a first episode of psychosis (FEP) will develop treatment-resistant schizophrenia (TRS), but there are currently no established clinically useful methods to predict this from baseline. We aimed to explore the predictive potential for clozapine use as a proxy for TRS of routinely collected, objective biomedical predictors at FEP onset, and to externally validate the model in a separate clinical sample of people with FEP. We developed and externally validated a forced-entry logistic regression risk prediction Model fOr cloZApine tReaTment, or MOZART, to predict up to 8-year risk of clozapine use from FEP using routinely recorded information including age, sex, ethnicity, triglycerides, alkaline phosphatase levels, and lymphocyte counts. We also produced a least-absolute shrinkage and selection operator (LASSO) based model, additionally including neutrophil count, smoking status, body mass index, and random glucose levels. The models were developed using data from two UK psychosis early intervention services (EIS) and externally validated in another UK EIS. Model performance was assessed via discrimination and calibration. We developed the models in 785 patients, and validated externally in 1,110 patients. Both models predicted clozapine use well at internal validation (MOZART: C 0.70; 95%CI 0.63,0.76; LASSO: 0.69; 95%CI 0.63,0.77). At external validation, discrimination performance reduced (MOZART: 0.63; 0.58,0.69; LASSO: 0.64; 0.58,0.69) but recovered after re-estimation of the lymphocyte predictor (C: 0.67; 0.62,0.73). Calibration plots showed good agreement between observed and predicted risk in the forced-entry model. We also present a decision-curve analysis and an online data visualisation tool. The use of routinely collected clinical information including blood-based biomarkers taken at FEP onset can help to predict the individual risk of clozapine use, and should be considered equally alongside other potentially useful information such as symptom scores in large-scale efforts to predict psychiatric outcomes.

The immune-stress/endocrine-redox-metabolic nature of psychosis' etiopathology; focus on the intersystemic pathways interactions

The evidence supporting the involvement of a number of systems in the neurobiological etiopathology of psychosis has recently grown exponentially. Indeed, the focus of research has changed from measuring solely neurotransmitters to estimating parameters from fields like immunity, stress/endocrine, redox, and metabolism. Yet, little is known regarding the exact role of each one of these fields on the formation of not only the brain neuropathological substrate in psychosis but also the associated general systemic pathology, in terms of causality directions. Research has shown deviations in the levels and/or function of basic effector molecules of the aforementioned fields namely cytokines, pro-/anti- oxidants, glucocorticoids, catecholamines, glucose, and lipids metabolites as well as kynurenines, in psychosis. Yet the evidence regarding their impact on neurotransmitters is minimal and the findings concerning these systems' interactions in the psychotic context are even more dispersed. The present review aims to draw holistically the frame of the hitherto known "players" in the field of psychosis' cellular pathobiology, with a particular focus on their in-between interactions.

Persistent Childhood and Adolescent Anxiety and Risk for Psychosis: A Longitudinal Birth Cohort Study

BACKGROUND

Persistent anxiety in childhood and adolescence could represent a novel treatment target for psychosis, potentially targeting activation of stress pathways and secondary nonresolving inflammatory response. Here, we examined the association between persistent anxiety through childhood and adolescence with individuals with psychotic experiences (PEs) or who met criteria for psychotic disorder (PD) at age 24 years. We also investigated whether C-reactive protein mediated any association.

METHODS

Data from the Avon Longitudinal Study of Parents and Children (ALSPAC) were available in 8242 children at age 8 years, 7658 at age 10 years, 6906 at age 13 years, and 3889 at age 24 years. The Development and Well-Being Assessment was administered to capture child and adolescent anxiety. We created a composite score of generalized anxiety at ages 8, 10, and 13. PEs and PD were assessed at age 24, derived from the Psychosis-like Symptoms Interview. The mean of C-reactive protein at ages 9 and 15 years was used as a mediator.

RESULTS

Individuals with persistent high levels of anxiety were more likely to develop PEs (odds ratio 2.02, 95% CI 1.26-3.23, p = .003) and PD at age 24 (odds ratio 4.23, 95% CI 2.27-7.88, p < .001). The mean of C-reactive protein at ages 9 and 15 mediated the associations of persistent anxiety with PEs (bias-corrected estimate -0.001, p = .013) and PD (bias-corrected estimate 0.001, p = .003).

CONCLUSIONS

Persistent high levels of anxiety through childhood and adolescence could be a risk factor for psychosis. Persistent anxiety is potentially related to subsequent psychosis via activation of stress hormones and nonresolving inflammation. These results contribute to the potential for preventive interventions in psychosis, with the novel target of early anxiety.

Inflammation subtypes in psychosis and their relationships with genetic risk for psychiatric and cardiometabolic disorders

Cardiometabolic disorders have known inflammatory implications, and peripheral measures of inflammation and cardiometabolic disorders are common in persons with psychotic disorders. Inflammatory signatures are also related to neurobiological and behavioral changes in psychosis. Relationships between systemic inflammation and cardiometabolic genetic risk in persons with psychosis have not been examined. Thirteen peripheral inflammatory markers and genome-wide genotyping were assessed in 122 participants (n ​= ​86 psychosis, n ​= ​36 healthy controls) of European ancestry. Cluster analyses of inflammatory markers classified higher and lower inflammation subgroups. Single-trait genetic risk scores (GRS) were constructed for each participant using previously reported GWAS summary statistics for the following traits: schizophrenia, bipolar disorder, major depressive disorder, coronary artery disease, type-2 diabetes, low-density lipoprotein, high-density lipoprotein, triglycerides, and waist-to-hip ratio. Genetic correlations across traits were quantified. Principal component (PC) analysis of the cardiometabolic GRSs generated six PC loadings used in regression models to examine associations with inflammation markers. Functional module discovery explored biological mechanisms of the inflammation association of cardiometabolic GRS genes. A subgroup of 38% persons with psychotic disorders was characterized with higher inflammation status. These higher inflammation individuals had lower BACS scores (p ​= ​0.038) compared to those with lower inflammation. The first PC of the cardiometabolic GRS matrix was related to higher inflammation status in persons with psychotic disorders (OR ​= ​2.037, p ​= ​0.001). Two of eight modules within the functional interaction network of cardiometabolic GRS genes were enriched for immune processes. Cardiometabolic genetic risk may predispose some individuals with psychosis to elevated inflammation which adversely impacts cognition associated with illness.

Inflammation and Brain Structure in Schizophrenia and Other Neuropsychiatric Disorders: A Mendelian Randomization Study

Importance

Previous in vitro and postmortem research suggests that inflammation may lead to structural brain changes via activation of microglia and/or astrocytic dysfunction in a range of neuropsychiatric disorders.

Objective

To investigate the relationship between inflammation and changes in brain structures in vivo and to explore a transcriptome-driven functional basis with relevance to mental illness.

Design, Setting, and Participants

This study used multistage linked analyses, including mendelian randomization (MR), gene expression correlation, and connectivity analyses. A total of 20 688 participants in the UK Biobank, which includes clinical, genomic, and neuroimaging data, and 6 postmortem brains from neurotypical individuals in the Allen Human Brain Atlas (AHBA), including RNA microarray data. Data were extracted in February 2021 and analyzed between March and October 2021.

Exposures

Genetic variants regulating levels and activity of circulating interleukin 1 (IL-1), IL-2, IL-6, C-reactive protein (CRP), and brain-derived neurotrophic factor (BDNF) were used as exposures in MR analyses.

Main Outcomes and Measures

Brain imaging measures, including gray matter volume (GMV) and cortical thickness (CT), were used as outcomes. Associations were considered significant at a multiple testing-corrected threshold of P < 1.1 × 10-4. Differential gene expression in AHBA data was modeled in brain regions mapped to areas significant in MR analyses; genes were tested for biological and disease overrepresentation in annotation databases and for connectivity in protein-protein interaction networks.

Results

Of 20 688 participants in the UK Biobank sample, 10 828 (52.3%) were female, and the mean (SD) age was 55.5 (7.5) years. In the UK Biobank sample, genetically predicted levels of IL-6 were associated with GMV in the middle temporal cortex (z score, 5.76; P = 8.39 × 10-9), inferior temporal (z score, 3.38; P = 7.20 × 10-5), fusiform (z score, 4.70; P = 2.60 × 10-7), and frontal (z score, -3.59; P = 3.30 × 10-5) cortex together with CT in the superior frontal region (z score, -5.11; P = 3.22 × 10-7). No significant associations were found for IL-1, IL-2, CRP, or BDNF after correction for multiple comparison. In the AHBA sample, 5 of 6 participants (83%) were male, and the mean (SD) age was 42.5 (13.4) years. Brain-wide coexpression analysis showed a highly interconnected network of genes preferentially expressed in the middle temporal gyrus (MTG), which further formed a highly connected protein-protein interaction network with IL-6 (enrichment test of expected vs observed network given the prevalence and degree of interactions in the STRING database: 43 nodes/30 edges observed vs 8 edges expected; mean node degree, 1.4; genome-wide significance, P = 4.54 × 10-9). MTG differentially expressed genes that were functionally enriched for biological processes in schizophrenia, autism spectrum disorder, and epilepsy.

Conclusions and Relevance

In this study, genetically determined IL-6 was associated with brain structure and potentially affects areas implicated in developmental neuropsychiatric disorders, including schizophrenia and autism.

Childhood immuno-metabolic markers and risk of depression and psychosis in adulthood: A prospective birth cohort study

BACKGROUND

Metabolic and inflammatory disorders commonly co-occur with depression and psychosis, with emerging evidence implicating immuno-metabolic dysfunction in their aetiology. Previous studies have reported metabolic dysfunction and inflammation in adults with depression and psychosis. However, longitudinal studies testing the direction of association, and the effects of different dimensions of early-life immuno-metabolic dysfunction on adult psychopathology are limited.

METHODS

Using data from 3258 birth cohort participants we examined longitudinal associations of three metabolic hormones (leptin, adiponectin, insulin) at age 9 with risks for depression- and psychosis-spectrum outcomes at age 24. In addition, using nine immuno-metabolic biomarkers (leptin, adiponectin, insulin, interleukin-6, C-Reactive protein, low density lipoprotein, high density lipoprotein, triglycerides, and BMI), we constructed an exploratory bifactor model showing a general immuno-metabolic factor and three specific factors (adiposity, inflammation, and insulin resistance), which were also used as exposures.

RESULTS

Childhood leptin was associated with adult depressive episode (adjusted odds ratio (aOR)= 1.31; 95% CI, 1.02-1.71) and negative symptoms (aOR=1.15; 95% CI, 1.07-1.24), but not positive psychotic symptoms. The general immuno-metabolic factor was associated with atypical depressive symptoms (aOR=1.07; 95% CI, 1.01-1.14) and psychotic experiences (aOR=1.21; 95% CI, 1.02-1.44). The adiposity factor was associated with negative symptoms (aOR=1.07; 95% CI 1.02-1.12). Point estimates tended to be larger in women, though 95% credible intervals overlapped with those for men. In women, the inflammatory factor was associated with depressive episodes (aOR=1.27; 95% CI, 1.03-1.57).

CONCLUSIONS

While general immuno-metabolic dysfunction in childhood may contribute to risks for both psychotic and depressive symptoms in adulthood, childhood adiposity and inflammation appear to be particularly linked to affective (depressive and negative), but not positive psychotic symptoms.

Plasma lipid alterations in young adults with psychotic experiences: A study from the Avon Longitudinal Study of Parents and Children cohort

BACKGROUND

Psychotic experiences (PEs) are associated with an increased risk of future psychotic and non-psychotic mental disorders. The identification of biomarkers of PEs may provide insights regarding the underlying pathophysiology.

METHODS

The current study applied targeted lipidomic approaches to compare plasma lipid profiles in participants from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort who did (n = 206) or did not (n = 206) have PEs when aged approximately 24 years.

RESULTS

In total, 202 lipids including 8 lipid classes were measured by using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). Eight lipid clusters were generated. Thirteen individual lipids were nominally significantly higher in the PEs group compared to the control group. After correction for multiple comparisons, 9 lipids comprising 3 lysophosphatidylcholines (LPCs), 2 phosphatidylcholines (PCs) and 4 triacylglycerols (TGs) remained significant. In addition, PEs cases had increased levels of TGs and LPCs with a low double bond count.

CONCLUSIONS

These findings indicate plasma lipidomic abnormalities in individuals experiencing PEs. The lipidomic profile measures could aid our understanding of the underlying pathophysiological mechanisms.

A population-based follow-up study shows high psychosis risk in women with PCOS

Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting up to 18% of women. Besides metabolic and fertility aspects, attention has lately been directed towards the detrimental effect of PCOS on psychological health. The objective of the study was to investigate whether women with PCOS are at higher risk for psychotic disorders. The study population derives from the Northern Finland Birth Cohort 1966 (N = 5889 women). The women with PCOS were identified by two simple questions on oligo-amenorrhea and hirsutism at age 31. Women reporting both symptoms were considered PCOS (N = 124) and asymptomatic women as controls (N = 2145). The diagnosis of psychosis was traced using multiple national registers up to the year 2016. Symptoms of psychopathology were identified using validated questionnaires at age 31. Women with PCOS showed an increased risk for any psychosis by age 50 (HR [95% CI] 2.99, [1.52-5.82]). Also, the risk for psychosis after age 31 was increased (HR 2.68 [1.21-5.92]). The results did not change after adjusting for parental history of psychosis, nor were they explained by body mass index or hyperandrogenism at adulthood. The scales of psychopathology differed between women with PCOS and non-PCOS controls showing more psychopathologies among the affected women. PCOS cases were found to be at a three-fold risk for psychosis, and they had increased psychopathological symptoms. PCOS should be taken into consideration when treating women in psychiatric care. More studies are required to further assess the relationship between PCOS and psychotic diseases.

Prenatal and Childhood Immuno-Metabolic Risk Factors for Adult Depression and Psychosis

Depression and psychosis have a developmental component to their origin. Epidemiologic evidence, which we synthesize in this nonsystematic review, suggests that early-life infection, inflammation, and metabolic alterations could play a role in the etiology of these psychiatric disorders. The risk of depression and psychosis is associated with prenatal maternal and childhood infections, which could be mediated by impaired neurodevelopment. Evidence suggests linear dose-response associations between elevated concentrations of circulating inflammatory markers in childhood, particularly the inflammatory cytokine interleukin 6, and the risk for depression and psychosis subsequently in early adulthood. Childhood inflammatory markers are also associated with persistence of depressive symptoms subsequently in adolescence and early adulthood. Developmental trajectories reflecting persistently high insulin levels during childhood and adolescence are associated with a higher risk of psychosis in adulthood, whereas increased adiposity during and after puberty is associated with the risk of depression. Together, these findings suggest that higher levels of infection, inflammation, and metabolic alterations commonly seen in people with depression and psychosis could be a cause for, rather than simply a consequence of, these disorders. Therefore, early-life immuno-metabolic alterations, as well as factors influencing these alterations such as adversity or maltreatment, could represent targets for prevention of these psychiatric disorders. Inflammation could also be an important treatment target for depression and psychosis. The field requires further research to examine sensitive periods when exposure to such immuno-metabolic alterations is most harmful. Interventional studies are also needed to test the potential usefulness of targeting early-life immuno-metabolic alterations for preventing adult depression and psychosis.

The prevalence and clinical correlates of metabolic syndrome and cardiometabolic alterations in 430 drug-naive patients in their first episode of schizophrenia

RATIONALE

Although metabolic abnormalities and metabolic syndrome (MetS) have been extensively investigated in schizophrenia, few studies have examined them in first-episode drug-naive (FEDN) patients.

OBJECTIVES

This study aimed to investigate the prevalence and clinical correlates of metabolic abnormalities in FEDN schizophrenia patients.

METHODS

A total of 430 FEDN schizophrenia patients and 453 controls were recruited. Various parameters were measured including BMI, waist circumference, blood pressure, lipid profiles, blood glucose, glycosylated hemoglobin (HbA1c), insulin, and homeostatic model assessment for insulin resistance (HOMA-IR).

RESULTS

Patients had a higher prevalence of MetS, hypertension, hypertriglyceridemia, hypo-HDL-C, elevated HAb1c, and elevated insulin than controls (19.1% vs. 6.6%, OR = 2.52; 33.3% vs. 12.1%, OR = 3.05; 30.5% vs. 16.1%, OR = 2.25; 43.1% vs. 24.0%, OR = 2.21; 25.6% vs. 10.8%, OR = 2.62; 9.1% vs. 0.9%, OR = 10.29; all pBonferroni < 0.001). Waist circumference was associated with PANSS general psychopathology and total score (correlation coefficient r = 0.17, pBonferroni < 0.001; correlation coefficient r = 0.16, pBonferroni = 0.004). Fasting glucose was associated with PANSS negative, general psychopathology, and total score (correlation coefficient r = 0.13, pBonferroni = 0.03; correlation coefficient r = 0.19, pBonferroni < 0.001; correlation coefficient r = 0.20, pBonferroni < 0.001). BMI (OR = 1.37), smoking (OR = 3.39), and HOMA-IR (OR = 5.60) were associated with MetS in FEDN schizophrenia (all p < 0.001).

CONCLUSIONS

Our results demonstrate that MetS and metabolic abnormalities co-existed in the early stages of schizophrenia without antipsychotics. Waist circumference and glucose were associated with psychopathological symptoms, while BMI, smoking, and HOMA-IR were associated with MetS in FEDN schizophrenia.

Fingertip advanced glycation end products and psychotic symptoms among adolescents

Case control studies have suggested that advanced glycation end products play a key role in the pathophysiology of chronic schizophrenia. However, the longitudinal association between advanced glycation end products and psychotic symptoms among drug-naïve adolescents remains unclear. This study examined whether advanced glycation end products could predict the trajectory of psychotic symptoms in drug-naive adolescents using data from prospective population-based biomarker subsample study of the Tokyo Teen Cohort. A total of 277 community-dwelling adolescents aged 13 years without antipsychotic medication were analyzed. Fingertip advanced glycation end products were measured in adolescents using noninvasive technology that can be used quickly. The trajectory of psychotic symptoms in a 12-month follow-up was assessed by experienced psychiatrists using a semi-structured interview. Of the 277 participants, 13 (4.7%) experienced persistent psychotic symptoms (psychotic symptoms at baseline and follow-up), 65 (23.5%) experienced transient psychotic symptoms (psychotic symptoms at baseline or follow-up), and 199 (71.8%) did not have psychotic symptoms. Multinomial logistic regression analysis adjusted for age and sex revealed that baseline fingertip advanced glycation end products might predict the risk of persistent psychotic symptoms (odds ratio = 1.68; 95% confidence interval, 1.05-2.69; P = 0.03). Altogether, fingertip advanced glycation end products potentially predicted the trajectory of psychotic symptoms among drug-naive adolescents, which indicated its involvement in the pathophysiology of early psychosis. Further studies are required to identify strategies to reduce adolescent advanced glycation end products, which may contribute to preventing the onset of psychosis.

Abnormal glucose metabolism is associated with clinical symptoms of adolescent-onset patients with first-episode drug-naive schizophrenia

Extensive studies have reported alterations in glucose metabolism in adult-onset patients with schizophrenia, but less attention has been paid to adolescent-onset patients with first-episode drug-naive (FEDN) schizophrenia. The purpose of this study was to compare glucose metabolism between adolescent-onset patients with FEDN schizophrenia and healthy controls and to investigate the relationship between glucose metabolism and clinical symptoms in patients with schizophrenia. This study compared the glycometabolism parameters between 51 adolescents-onset patients with FEDN schizophrenia and 51 age- and sex-matched healthy controls. The Chinese version of the Positive and Negative Syndrome Scale (PANSS), Hamilton Anxiety Rating Scale, and Hamilton Depression Rating Scale were used to assess patients' psychiatric, anxiety, and depressive symptoms. The results showed that compared with healthy controls, the patients had a significantly higher prevalence of impaired fasting glucose and insulin resistance, as well as higher fasting plasma glucose, fasting plasma insulin, homeostasis model assessment of insulin resistance index (HOMA-IR) and triglycerides, but lower high-density lipoprotein cholesterol levels. Moreover, HOMA-IR was negatively associated with PANSS general psychopathology, while glucose was positively correlated with depressive symptoms among patients. In sum, adolescent-onset patients with FEDN schizophrenia are more likely to have abnormal glucose metabolism and dyslipidemia than their healthy counterparts. Moreover, abnormal glucose metabolism may be closely related to the psychopathological symptoms of schizophrenia in the early stage of the disease.

COVID-19 in People With Schizophrenia: Potential Mechanisms Linking Schizophrenia to Poor Prognosis

As the global burden of mortality from COVID-19 continues to rise, an understanding of who is most at risk of adverse outcomes is of paramount importance. Pre-existing cardiometabolic, renal and respiratory diseases as well as old age are well-established risk factors associated with disease severity and mortality among patients with COVID-19. However, mounting evidence also indicates an increased susceptibility to, and risk of adverse outcomes from COVID-19 in people with schizophrenia, independent of age and comorbidity. Therefore, elucidating the underlying pathophysiological mechanisms which may increase the risk of poor outcomes in people with schizophrenia is of crucial importance. Here, we provide a narrative on the current understanding of COVID-19 in patients with schizophrenia and propose potential mechanisms which may link schizophrenia with an increased susceptibility to, and greater risk of adverse outcomes from COVID-19. Given the existing knowledge gaps, robust clinical and biological studies are required to further our understanding of some of these underlying mechanisms, so that effective prevention and treatment strategies for COVID-19 in patients with schizophrenia can be developed.

Investigation of glycaemic traits in psychiatric disorders using Mendelian randomisation revealed a causal relationship with anorexia nervosa

Data from observational studies have suggested an involvement of abnormal glycaemic regulation in the pathophysiology of psychiatric illness. This may be an attractive target for clinical intervention as glycaemia can be modulated by both lifestyle factors and pharmacological agents. However, observational studies are inherently confounded, and therefore, causal relationships cannot be reliably established. We employed genetic variants rigorously associated with three glycaemic traits (fasting glucose, fasting insulin, and glycated haemoglobin) as instrumental variables in a two-sample Mendelian randomisation analysis to investigate the causal effect of these measures on the risk for eight psychiatric disorders. A significant protective effect of a natural log transformed pmol/L increase in fasting insulin levels was observed for anorexia nervosa after the application of multiple testing correction (OR = 0.48 [95% CI: 0.33-0.71]-inverse-variance weighted estimate). There was no consistently strong evidence for a causal effect of glycaemic factors on the other seven psychiatric disorders considered. The relationship between fasting insulin and anorexia nervosa was supported by a suite of sensitivity analyses, with no statistical evidence of instrument heterogeneity or horizontal pleiotropy. Further investigation is required to explore the relationship between insulin levels and anorexia.

Longitudinal Trends in Childhood Insulin Levels and Body Mass Index and Associations With Risks of Psychosis and Depression in Young Adults

IMPORTANCE

Cardiometabolic disorders often occur concomitantly with psychosis and depression, contribute to high mortality rates, and are detectable from the onset of the psychiatric disorders. However, it is unclear whether longitudinal trends in cardiometabolic traits from childhood are associated with risks for adult psychosis and depression.

OBJECTIVE

To examine whether specific developmental trajectories of fasting insulin (FI) levels and body mass index (BMI) from early childhood were longitudinally associated with psychosis and depression in young adults.

DESIGN, SETTING, AND PARTICIPANTS

A cohort study from the Avon Longitudinal Study of Parents and Children, a prospective study including a population-representative British cohort of 14 975 individuals, was conducted using data from participants aged 1 to 24 years. Body mass index and FI level data were used for growth mixture modeling to delineate developmental trajectories, and associations with psychosis and depression were assessed. The study was conducted between July 15, 2019, and March 24, 2020.

EXPOSURES

Fasting insulin levels were measured at 9, 15, 18, and 24 years, and BMI was measured at 1, 2, 3, 4, 7, 9, 10, 11, 12, 15, 18, and 24 years. Data on sex, race/ethnicity, paternal social class, childhood emotional and behavioral problems, and cumulative scores of sleep problems, average calorie intake, physical activity, smoking, and alcohol and substance use in childhood and adolescence were examined as potential confounders.

MAIN OUTCOMES AND MEASURES

Psychosis risk (definite psychotic experiences, psychotic disorder, at-risk mental state status, and negative symptom score) depression risk (measured using the computerized Clinical Interview Schedule-Revised) were assessed at 24 years.

RESULTS

From data available on 5790 participants (3132 [54.1%] female) for FI levels and data available on 10 463 participants (5336 [51.0%] female) for BMI, 3 distinct trajectories for FI levels and 5 distinct trajectories for BMI were noted, all of which were differentiated by mid-childhood. The persistently high FI level trajectory was associated with a psychosis at-risk mental state (adjusted odds ratio [aOR], 5.01; 95% CI, 1.76-13.19) and psychotic disorder (aOR, 3.22; 95% CI, 1.29-8.02) but not depression (aOR, 1.38; 95% CI, 0.75-2.54). A puberty-onset major increase in BMI was associated with depression (aOR, 4.46; 95% CI, 2.38-9.87) but not psychosis (aOR, 1.98; 95% CI, 0.56-7.79).

CONCLUSIONS AND RELEVANCE

The cardiometabolic comorbidity of psychosis and depression may have distinct, disorder-specific early-life origins. Disrupted insulin sensitivity could be a shared risk factor for comorbid cardiometabolic disorders and psychosis. A puberty-onset major increase in BMI could be a risk factor or risk indicator for adult depression. These markers may represent targets for prevention and treatment of cardiometabolic disorders in individuals with psychosis and depression.

The potential shared role of inflammation in insulin resistance and schizophrenia: A bidirectional two-sample mendelian randomization study

BACKGROUND

Insulin resistance predisposes to cardiometabolic disorders, which are commonly comorbid with schizophrenia and are key contributors to the significant excess mortality in schizophrenia. Mechanisms for the comorbidity remain unclear, but observational studies have implicated inflammation in both schizophrenia and cardiometabolic disorders separately. We aimed to examine whether there is genetic evidence that insulin resistance and 7 related cardiometabolic traits may be causally associated with schizophrenia, and whether evidence supports inflammation as a common mechanism for cardiometabolic disorders and schizophrenia.

METHODS AND FINDINGS

We used summary data from genome-wide association studies of mostly European adults from large consortia (Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) featuring up to 108,557 participants; Diabetes Genetics Replication And Meta-analysis (DIAGRAM) featuring up to 435,387 participants; Global Lipids Genetics Consortium (GLGC) featuring up to 173,082 participants; Genetic Investigation of Anthropometric Traits (GIANT) featuring up to 339,224 participants; Psychiatric Genomics Consortium (PGC) featuring up to 105,318 participants; and Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium featuring up to 204,402 participants). We conducted two-sample uni- and multivariable mendelian randomization (MR) analysis to test whether (i) 10 cardiometabolic traits (fasting insulin, high-density lipoprotein and triglycerides representing an insulin resistance phenotype, and 7 related cardiometabolic traits: low-density lipoprotein, fasting plasma glucose, glycated haemoglobin, leptin, body mass index, glucose tolerance, and type 2 diabetes) could be causally associated with schizophrenia; and (ii) inflammation could be a shared mechanism for these phenotypes. We conducted a detailed set of sensitivity analyses to test the assumptions for a valid MR analysis. We did not find statistically significant evidence in support of a causal relationship between cardiometabolic traits and schizophrenia, or vice versa. However, we report that a genetically predicted inflammation-related insulin resistance phenotype (raised fasting insulin (raised fasting insulin (Wald ratio OR = 2.95, 95% C.I, 1.38-6.34, Holm-Bonferroni corrected p-value (p) = 0.035) and lower high-density lipoprotein (Wald ratio OR = 0.55, 95% C.I., 0.36-0.84; p = 0.035)) was associated with schizophrenia. Evidence for these associations attenuated to the null in multivariable MR analyses after adjusting for C-reactive protein, an archetypal inflammatory marker: (fasting insulin Wald ratio OR = 1.02, 95% C.I, 0.37-2.78, p = 0.975), high-density lipoprotein (Wald ratio OR = 1.00, 95% C.I., 0.85-1.16; p = 0.849), suggesting that the associations could be fully explained by inflammation. One potential limitation of the study is that the full range of gene products from the genetic variants we used as proxies for the exposures is unknown, and so we are unable to comment on potential biological mechanisms of association other than inflammation, which may also be relevant.

CONCLUSIONS

Our findings support a role for inflammation as a common cause for insulin resistance and schizophrenia, which may at least partly explain why the traits commonly co-occur in clinical practice. Inflammation and immune pathways may represent novel therapeutic targets for the prevention or treatment of schizophrenia and comorbid insulin resistance. Future work is needed to understand how inflammation may contribute to the risk of schizophrenia and insulin resistance.

Inflammatory and cardiometabolic markers at presentation with first episode psychosis and long-term clinical outcomes: A longitudinal study using electronic health records

Approximately one third of patients presenting with a first episode of psychosis need long-term support, but there is a limited understanding of the sociodemographic or biological factors that predict this outcome. We used electronic health records from a naturalistic cohort of consecutive patients referred to an early intervention in psychosis service to address this question. We extracted data on demographic (age, sex, ethnicity and marital status), immune (differential cell count measures and C-reactive protein (CRP)) and metabolic (cholesterol, triglycerides, glucose, glycated haemoglobin, blood pressure, body mass index (BMI)) factors at baseline, and subsequent need for long-term secondary (specialist) psychiatric care. Of 749 patients with outcome data available, 447 (60%) had a good outcome and were discharged to primary care, while 302 (40%) required follow-up by secondary mental health services indicating a worse outcome. The need for ongoing secondary mental healthcare was associated with high triglyceride levels (adjusted odds ratio/OR = 7.32, 95% CI 2.26-28.06), a low basophil:lymphocyte ratio (adjusted OR = 0.14, 95% CI 0.02-0.58), and a high monocyte count (adjusted OR = 2.78, 95% CI 1.02-8.06) at baseline. The associations for baseline basophil (unadjusted OR = 0.27 per SD, 95% CI 0.10-0.62) and platelet counts (unadjusted OR = 2.88, 95% CI 1.29-6.63) attenuated following adjustment for BMI. Baseline CRP levels or BMI were not associated with long-term psychiatric outcomes. In conclusion, we provide evidence that triglyceride levels and several blood cell counts measured at presentation may be clinically useful markers of long-term prognosis for first episode psychosis in clinical settings. These findings will require replication.

Common mechanisms for type 2 diabetes and psychosis: Findings from a prospective birth cohort

BACKGROUND

Psychosis and type 2 diabetes mellitus (T2DM) are commonly comorbid and may share pathophysiologic mechanisms. To investigate shared genetic variation and inflammation as potential common mechanisms, we tested: (i) associations between genetic predisposition for T2DM and psychotic experiences and psychotic disorder in young adults; (ii) the association between genetic predisposition for schizophrenia and insulin resistance (IR), a precursor of T2DM; and (iii) whether these associations are mediated by childhood inflammation.

METHODS

Psychotic experiences (PEs), psychotic disorder and IR were assessed at age 18. Polygenic risk scores (PRS) for T2DM and schizophrenia were derived based on large genome-wide association studies. Associations between PRS and psychotic/IR outcomes were assessed using regression analysis based on 3768 ALSPAC birth cohort participants with complete data. Inflammatory markers C-reactive protein (CRP) and interleukin 6 (IL-6) measured at age 9 were used in regression and mediation analyses.

RESULTS

Genetic predisposition for T2DM was associated with PEs (adjusted OR = 1.21; 95% CI, 1.01-1.45) and psychotic disorder (adjusted OR = 1.51; 95% CI, 1.04-2.03) at age 18 in a linear dose-response fashion. Genetic predisposition for schizophrenia was weakly associated with IR (adjusted OR = 1.10; 95% C·I, 0.99-1.22) at age 18. The association between genetic risk for T2DM and PEs was partly mediated by childhood CRP (p = .040).

CONCLUSIONS

Comorbidity between psychosis and T2DM may be partly underpinned by shared genes and inflammation. A summation of minor genetic variation representing lifetime risk for T2DM at conception may predispose individuals to psychosis in adulthood by influencing physiologic changes, such as low-grade inflammation, detectable as early as childhood.

Cardiometabolic risk prediction algorithms for young people with psychosis: a systematic review and exploratory analysis

OBJECTIVE

Cardiometabolic risk prediction algorithms are common in clinical practice. Young people with psychosis are at high risk for developing cardiometabolic disorders. We aimed to examine whether existing cardiometabolic risk prediction algorithms are suitable for young people with psychosis.

METHODS

We conducted a systematic review and narrative synthesis of studies reporting the development and validation of cardiometabolic risk prediction algorithms for general or psychiatric populations. Furthermore, we used data from 505 participants with or at risk of psychosis at age 18 years in the ALSPAC birth cohort, to explore the performance of three algorithms (QDiabetes, QRISK3 and PRIMROSE) highlighted as potentially suitable. We repeated analyses after artificially increasing participant age to the mean age of the original algorithm studies to examine the impact of age on predictive performance.

RESULTS

We screened 7820 results, including 110 studies. All algorithms were developed in relatively older participants, and most were at high risk of bias. Three studies (QDiabetes, QRISK3 and PRIMROSE) featured psychiatric predictors. Age was more strongly weighted than other risk factors in each algorithm. In our exploratory analysis, calibration plots for all three algorithms implied a consistent systematic underprediction of cardiometabolic risk in the younger sample. After increasing participant age, calibration plots were markedly improved.

CONCLUSION

Existing cardiometabolic risk prediction algorithms cannot be recommended for young people with or at risk of psychosis. Existing algorithms may underpredict risk in young people, even in the face of other high-risk features. Recalibration of existing algorithms or a new tailored algorithm for the population is required.

The Role of Genetic Variation of BMI, Body Composition, and Fat Distribution for Mental Traits and Disorders: A Look-Up and Mendelian Randomization Study

Anthropometric traits and mental disorders or traits are known to be associated clinically and to show genetic overlap. We aimed to identify genetic variants with relevance for mental disorders/traits and either (i) body mass index (or obesity), (ii) body composition, (and/or) (iii) body fat distribution. We performed a look-up analysis of 1,005 genome-wide significant SNPs for BMI, body composition, and body fat distribution in 15 mental disorders/traits. We identified 40 independent loci with one or more SNPs fulfilling our threshold significance criterion (P < 4.98 × 10-5) for the mental phenotypes. The majority of loci was associated with schizophrenia, educational attainment, and/or intelligence. Fewer associations were found for bipolar disorder, neuroticism, attention deficit/hyperactivity disorder, major depressive disorder, depressive symptoms, and well-being. Unique associations with measures of body fat distribution adjusted for BMI were identified at five loci only. To investigate the potential causality between body fat distribution and schizophrenia, we performed two-sample Mendelian randomization analyses. We found no causal effect of body fat distribution on schizophrenia and vice versa. In conclusion, we identified 40 loci which may contribute to genetic overlaps between mental disorders/traits and BMI and/or shape related phenotypes. The majority of loci identified for body composition overlapped with BMI loci, thus suggesting pleiotropic effects.

Metabolic Parameters in Patients with Prader-Willi Syndrome and DiGeorge Syndrome with Respect to Psychopathological Manifestation

PURPOSE

The purpose of our study was to compare the metabolic parameters in two genetic syndromes with a proven high risk of developing psychiatric comorbidities. These comorbidities, especially mood and psychotic disorders, may be associated with a risk of obesity, type 2 diabetes and other components of metabolic syndrome regardless of antipsychotic treatment.

PATIENTS AND METHODS

Two groups of children diagnosed with Prader - Willi syndrome (PWS) (n = 20) and DiGeorge syndrome (DGS) (n = 18), aged 7-18 years, were enrolled. Behavioral symptoms and co-occurring psychopathological symptoms were assessed using the Child Behavior Checklist (CBCL). The levels of following biochemical parameters were measured: glucose, insulin, high-sensitivity C-reactive protein, total cholesterol, low- and high-density lipoproteins (LDL and HDL), triglycerides and non-HDL cholesterol. Additionally, the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated.

RESULTS

There were significantly higher levels of insulin and non-HDL in patients with PWS compared to those with DGS. The scores of four CBCL subscales (social problems, thought problems, delinquent behavior and aggressive behavior) were significantly higher in PWS patients. Higher scores of the CBCL-thought problems were associated with significantly higher levels of insulin as well as HOMA-IR.

CONCLUSION

Patients with PWS seem to be more prone to develop subclinical metabolic dysregulation, in terms of elevated non-HDL levels and insulin levels, compared to DGS patients. Altered insulin sensitivity, present in both groups, even though it is not a specific risk factor, might be related to thought problems associated with psychosis.

Designing a feasible exercise intervention in first-episode psychosis: Exercise quality, engagement and effect

First-episode psychosis (FEP) is the first presentation of a psychotic disorder that usually propagates during early adulthood. FEP represents an important early intervention point to attenuate the metabolic risks associated with psychosis and its treatment. Exercise has potential to improve metabolic and functional outcome, but engaging this population in regular exercise is typically difficult. Promoting enjoyment and attendance may improve participation. 22 men with FEP were randomised to a 12-week intervention of exercise training, or treatment as usual. Exercise was pre-standardised based on measures of heart rate to assess intensity. Symptoms of psychosis were assessed, alongside measures of quality of life, disability and habitual activity. The study observed 83% attendance at exercise sessions, with target intensity attained. There were clinically meaningful decreases in PANSS positive (17.31%) and general psychopathology (10.98%) scores and exercise was protective of negative score increase observed in the control group (13.89%). Assessment of disability declined after training (12.65%) compared with a 20.78% increase in controls. This study demonstrated that engagement of FEP patients in an intervention of high quality exercise was possible. Positive changes in psychopathology scores and disability show that the benefits of regular exercise are achievable with a potential positive impact on clinical presentation.

Health Conditions and Psychotic Experiences: Cross-Sectional Findings From the American Life Panel

Background: People with psychotic disorders have poor health, but studies have shown that people who have a milder and more prevalent form of psychosis (psychotic experiences) are also at risk for health problems. More research is needed to examine a broad range of health conditions to discover new relations with psychotic experiences. Methods: We analyzed cross-sectional data from the American Life Panel, a nationally representative sample of the United States adult population. Using multivariable logistic regression, we examined the associations between health conditions (categories of conditions, specific conditions, count of conditions) and lifetime psychotic experiences. Results: Approximately 71% of the weighted sample reported at least one health condition, and around 18% reported a lifetime psychotic experience. Using multivariable logistic regression, we found that several health conditions were associated with psychotic experiences, including pain due to other causes, neck pain, other injury, any gastrointestinal/kidney problem, liver diseases/cirrhosis, any nervous/sensory problem, migraine, nerve problem causing numbness/pain, any other disorder, specifically sleep disorder, chronic fatigue syndrome, and chronic pain. Further, the count of specific health conditions and the count of categories were associated with greater odds of psychotic experiences. Conclusion: We found that numerous health conditions were associated with psychotic experiences.

Prevalence of metabolic syndrome and its associated risk factors in an African-Caribbean population with severe mental illness

This cross-sectional study aims to determine the prevalence of metabolic syndrome (MetS) in patients with severe mental illness (SMI) on a Caribbean island, Curaçao, using the modified National Cholesterol Education Program Adult Treatment Panel III criteria. Among 350 patients (240 men and 110 women) with a mean age of 51.9 years (S.D.=13.5) MetS prevalence was 37.4%, significantly higher in female patients (63.6%) compared to male patients (25.4%). Increased waist circumference was present in 51.1%, low HDL in 50.6%, hypertension in 49.4%, hyperglycemia in 28.6% and 25.7% had hypertriglyceridemia. Except for hypertriglyceridemia, all criteria were more prevalent in female patients. Binary logistic regression analysis indicated that female gender, outpatient treatment setting and the absence of substance use disorder were all significant predictors for MetS. Compared to data from the general population obtained by the 2013 National Health Survey Curaçao, this study showed significantly higher prevalence of diabetes and hypertension in patients with SMI. Moreover, female patients had the highest prevalence of diabetes (28.2%), obesity (50.0%) and increased waist circumference (88.2%). This study demonstrates that African-Caribbean patients with SMI are at high-risk for MetS, especially female patients. Our data suggest to focus on modifiable lifestyle risk factors, as promoting physical activity and healthy dietary habits.

Effects of chronic physical illness on treatment outcomes among patients with schizophrenia

PURPOSE OF REVIEW

Previous research has demonstrated the high prevalence of medical comorbidity and multimorbidity among patients with schizophrenia. However, little is known regarding the potential effects of chronic physical illness (CPI) on schizophrenia treatment outcomes. In the present report, we aim to provide an updated review of the relevant literature.

RECENT FINDINGS

We searched MEDLINE for studies published between 2017 and 2018. After screening 683 articles, we included six studies of adequate quality. Five of these studies reported significant associations between several CPIs and different schizophrenia treatment outcomes, whereas the remaining study did not. Significant effects were low to moderate in size. CPIs with significant effects on treatment outcomes included metabolic syndrome, cardiovascular disease, and asthma. No significant effects were observed for diabetes, chronic obstructive pulmonary disease, hepatitis, hypertension, hyperlipidemia, or lung conditions. One study reported a significant association between the total number of CPIs and the overall number of psychiatric rehospitalizations.

SUMMARY

In addition to increasing the risk of premature mortality, accumulating evidence indicates that various CPIs affect schizophrenia treatment outcomes. Thus, researchers and healthcare practitioners should increase efforts to raise awareness regarding the importance of physical health among patients with schizophrenia. Further high-quality studies are required, particularly those targeting the potential effects of individual CPIs.

Integrated Lipidomics and Proteomics Point to Early Blood-Based Changes in Childhood Preceding Later Development of Psychotic Experiences: Evidence From the Avon Longitudinal Study of Parents and Children

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. We assessed the lipids, lysophosphatidylcholines (n = 11) and phosphatidylcholines (n = 61), and the protein members of the coagulation pathway (n = 22) and integrated these data with complement pathway protein data already available on these subjects.

RESULTS

Twelve phosphatidylcholines, four lysophosphatidylcholines, and the coagulation protein plasminogen were altered between the control and PEs groups after correction for multiple comparisons. Lipidomic and proteomic datasets were integrated into a multivariate network displaying a strong relationship between most lipids that were significantly associated with PEs and plasminogen. Finally, an unsupervised clustering approach identified four different clusters, with one of the clusters presenting the highest case-control ratio (p < .01) and associated with a higher concentration of smaller low-density lipoprotein cholesterol particles.

CONCLUSIONS

Our findings indicate that the lipidome and proteome of subjects who report PEs at 18 years of age are already altered at 12 years of age, indicating that metabolic dysregulation may contribute to an early vulnerability to PEs and suggesting crosstalk between these lysophosphatidylcholines, phosphatidylcholines, and coagulation and complement proteins.

Polygenic risk for schizophrenia, disordered eating behaviours and body mass index in adolescents

BACKGROUND

Recent studies suggest psychotic and eating disorders can be comorbid and could have shared genetic liability. However, this comorbidity has been overlooked in the epidemiological literature.AimsTo test whether polygenic risk scores (PRS) for schizophrenia are associated with disordered eating behaviours and body mass index (BMI) in the general population.

METHOD

Using data from the Avon Longitudinal Study of Parents and Children and random-effects logistic and linear regression models, we investigated the association between PRS for schizophrenia and self-reported disordered eating behaviours (binge eating, purging, fasting and excessive exercise) and BMI at 14, 16 and 18 years.

RESULTS

Of the 6920 children with available genetic data, 4473 (64.6%) and 5069 (73.3%) had at least one disordered eating and one BMI outcome measurement, respectively. An s.d. increase in PRS was associated with greater odds of having binge eating behaviours (odds ratio, 1.36; 95% CI 1.16-1.60) and lower BMI (coefficient, -0.03; 95% CI, -0.06 to -0.01).

CONCLUSIONS

Our findings suggest the presence of shared genetic risk between schizophrenia and binge eating behaviours. Intermediate phenotypes such as impaired social cognition and irritability, previously shown to be positively correlated in this sample with schizophrenia PRS, could represent risk factors for both phenotypes. Shared genetic liability between binge eating and schizophrenia could also explain higher rates of metabolic syndrome in individuals with schizophrenia, as binge eating could be a mediator of this association in drug-naïve individuals. The finding of an association between greater PRS and lower BMI, although consistent with existing epidemiological and genetic literature, requires further investigation.Declaration of interestNone.

Neuroimaging Markers of Risk, Disease Expression, and Resilience to Bipolar Disorder

PURPOSE OF REVIEW

Familial predisposition to bipolar disorder is associated with increased risk of affective morbidity in the first-degree relatives of patients. Nevertheless, a substantial proportion of relatives remain free of psychopathology throughout their lifetime. A series of studies reviewed here were designed to test whether resilience in these high-risk individuals is associated with adaptive brain plasticity.

RECENT FINDINGS

The findings presented here derive from structural and functional magnetic resonance imaging data obtained from patients, their resilient first-degree relatives, and healthy individuals. Patients and relatives showed similar abnormalities in activation and connectivity while performing tasks of interference control and facial affect recognition and in the resting-state connectivity of sensory and motor regions. Resilient relatives manifested unique neuroimaging features that differentiated them from patients and healthy individuals. Specifically, they had larger cerebellar vermis volume, enhanced prefrontal connectivity during task performance, and enhanced functional integration of the default mode network in task-free conditions. Resilience to bipolar disorder is not the reverse of risk but is associated with adaptive brain changes indicative of increased neural reserve. This line of research may open new avenues in preventing and treating bipolar disorder.

Oxidative Stress and Inflammation in First-Episode Psychosis: A Systematic Review and Meta-analysis

Despite mixed findings, increasing evidence suggests that people with first-episode psychosis (FEP) show increased pro-inflammatory and pro-oxidative status. We used the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to conduct a systematic literature search of cross-sectional studies comparing in vivo inflammatory and oxidative blood markers between FEP patients and healthy controls. We analyzed 61 independent samples from 59 publications, including 3002 patients with FEP (ie, patients with FEP, early psychosis, first-episode schizophrenia or early schizophrenia) and 2806 controls. After controlling for multiple comparisons, our meta-analysis showed that total antioxidant status and docosahexaenoic acid levels were significantly lower in FEP patients than in controls, whereas levels of homocysteine, interleukin-6 and tumor necrosis factor alpha were significantly higher in FEP patients than in controls. This suggests that FEP patients had reduced antioxidant status and a pro-inflammatory imbalance, and that these biological processes may be targets for managing FEP.

Cytokines, Oxidative Stress and Cellular Markers of Inflammation in Schizophrenia

In this article, we review current evidence linking immune dysfunction in schizophrenia and related psychotic disorders focusing particularly on circulating cytokines, oxidative stress and cellular markers of inflammation in various stages on illness from drug-naïve first episode psychosis to chronic schizophrenia. Acute psychotic episode is associated with low-grade systemic inflammation in some patients, as reflected by increased concentrations of cytokines and other inflammatory markers in peripheral blood. Evidence from general population-based longitudinal cohort studies reporting an association between elevated inflammatory markers in childhood/adolescence and risk of schizophrenia and related psychosis subsequently in adulthood suggest that inflammation could be a causal risk factor for psychosis rather than simply be a consequence of illness. Mendelian randomization studies also suggest that associations between IL-6, CRP and schizophrenia are likely to be causal. In addition, we discuss evidence for disruptions in oxidative stress markers and CSF cytokine levels in schizophrenia, and potential reasons for reported trans-diagnostic associations for inflammatory cytokines including role of early-life adversity/maltreatment. We argue that low-grade inflammation is a clinically useful feature, because it is associated with poor response to antipsychotic medication in first episode psychosis. We discuss clinical implications for immunological understanding of schizophrenia including scope for clinical trials of anti-inflammatory agents and notable gaps in current knowledge, and offer suggestions for future research.

An association between YKL-40 and type 2 diabetes in psychotic disorders

OBJECTIVE

This study examines if YKL-40 is increased in individuals with psychotic disorders and if elevated YKL-40 levels at baseline is associated with subsequent development of type 2 diabetes.

METHOD

A total of 1383 patients with a diagnosis of schizophrenia or affective psychosis and 799 healthy controls were recruited in the period 2002-2015. Plasma YKL-40 and metabolic risk factors were measured and medication was recorded. Using national registry data, association between baseline risk factors and later development of type 2 diabetes was assessed using Cox proportional hazards models.

RESULTS

Plasma YKL-40 was higher in patients vs. healthy controls also after adjusting for metabolic risk factors, with no difference between the schizophrenia and affective psychosis groups. Patients were diagnosed with type 2 diabetes at a significantly younger age. Multivariate Cox regression analyses showed that elevated YKL-40 (hazard ratio (HR) = 5.6, P = 0.001), elevated glucose (HR = 3.6, P = 0.001), and schizophrenia diagnosis (HR = 3.0, P = 0.014) at baseline were associated with subsequent development of type 2 diabetes.

CONCLUSIONS

Patients with psychotic disorders have at baseline increased levels of YKL-40 beyond the effect of comorbid type 2 diabetes and metabolic risk factors. Elevated YKL-40 level at baseline is associated with later development of type 2 diabetes.

Longitudinal associations between psychotic experiences and disordered eating behaviours in adolescence: a UK population-based study

BACKGROUND

Psychotic experiences might represent non-specific markers of poor mental health in adolescence. However, only a few predominantly cross-sectional studies have tested their association with disordered eating behaviours in adolescent and adult populations. The aim of this study was to explore the association between psychotic experiences at age 13 years, and disordered eating behaviours and body-mass index (BMI) at age 18 years.

METHODS

We used data from the Avon Longitudinal Study of Parents and Children, a longitudinal birth cohort based in Avon (England, UK) including mothers with an expected delivery date between April 1, 1991, and Dec 31, 1992, and their children. Psychotic experiences (such as delusions and hallucinations) and BMI were measured at clinical assessments when children were nearly aged 13 years, and data on disordered eating behaviours (ie, presence of binge eating, purging, fasting, or excessive exercise for weight loss; any of these behaviours [included to increase statistical power]; and number of behaviours [included to investigate severity]) were obtained via a postal questionnaire that used adapted questions from the Youth Risk Behaviour Surveillance System questionnaire at approximately age 18 years. For each outcome, we ran a univariable model and four multivariable models (logistic, linear [for BMI], or negative binomial [for the number of behaviours] regression), progressively adjusting for child and maternal sociodemographic, physical, and mental health characteristics (including child's sex, and maternal age, marital status, and highest academic qualification); autistic traits at age 7 years (measured with the Social and Communication Disorder Checklist); baseline BMI at age 13 years, and depressive symptoms at baseline (ie, at age 13 years when psychotic experiences were measured: childs' symptoms measured with the Moods and feelings Questionnaire, and maternal symptoms measured at 32 weeks' gestation with the Edinburgh Postnatal Depression Scale). We imputed missing outcome and covariate data.

FINDINGS

Our sample included 6361 children, of whom 734 (12%) reported psychotic experiences at age 13 years. In univariable models, psychotic experiences were associated with greater odds of reporting any disordered eating behaviours (odds ratio [OR] 1·92, 95% CI 1·46-2·52; p<0·0001), and more severe symptoms (as measured by the number of disordered eating behaviours: 0·58, 0·32-0·84; p<0·0001) at age 18 years. These associations were slightly attenuated by adjustment for maternal and child characteristics (any disordered eating behaviours OR 1·82, 95% CI 1·35-2·44, p<0·0001; number of disordered eating behaviours 0·49, 95% CI 0·23-0·75, p<0·00001), autistic traits at age 7 years (any disordered eating behaviours OR 1·80, 95% CI 1·34-2·41, p<0·0001; number of disordered eating behaviours 0·48, 95% CI 0·22-0·74, p<0·00001), and BMI (any disordered-eating behaviours OR 1·83, 95% CI 1·36-2·46, p<0·0001; number of disordered-eating behaviours 0·32, 95% CI 0·06-0·57, p<0·00001) Adjusting for baseline depressive symptoms attenuated, but not removed, these associations (any disordered eating OR 1·50, 95% CI 1·10-2·03, p=0·010; more severe symptoms 0·32, 0·06-0·57, p=0·017). Psychotic experiences were also associated with greater binge eating, purging, and fasting behaviours, although some associations weakened after controlling for depressive symptoms. We noted no associations between psychotic experiences and excessive exercise or BMI in any of the models.

INTERPRETATION

Our findings suggested that psychotic experiences are markers of increased risk for several disordered eating behaviours in late adolescence, possibly by indicating more severe psychopathology in early adolescence. More research investigating shared risk factors for psychotic experiences and eating disorders is warranted to elucidate shared and specific causal pathways.

FUNDING

Wellcome Trust, the Royal Society, University College London Hospitals National Institute for Health Research Biomedical Research Centre, UK Medical Research Council, and the University of Bristol.