A systematic review of cannabidiol dosing in clinical populations

AIMS

Cannabidiol (CBD) is a cannabis-derived medicinal product with potential application in a wide-variety of contexts; however, its effective dose in different disease states remains unclear. This review aimed to investigate what doses have been applied in clinical populations, in order to understand the active range of CBD in a variety of medical contexts.

METHODS

Publications involving administration of CBD alone were collected by searching PubMed, EMBASE and ClinicalTrials.gov.

RESULTS

A total of 1038 articles were retrieved, of which 35 studies met inclusion criteria covering 13 medical contexts. Twenty-three studies reported a significant improvement in primary outcomes (e.g. psychotic symptoms, anxiety, seizures), with doses ranging between <1 and 50 mg/kg/d. Plasma concentrations were not provided in any publication. CBD was reported as well tolerated and epilepsy was the most frequently studied medical condition, with all 11 studies demonstrating positive effects of CBD on reducing seizure frequency or severity (average 15 mg/kg/d within randomised controlled trials). There was no signal of positive activity of CBD in small randomised controlled trials (range n = 6-62) assessing diabetes, Crohn's disease, ocular hypertension, fatty liver disease or chronic pain. However, low doses (average 2.4 mg/kg/d) were used in these studies.

CONCLUSION

This review highlights that CBD has a potential wide range of activity in several pathologies. Pharmacokinetic studies as well as conclusive phase III trials to elucidate effective plasma concentrations within medical contexts are severely lacking and highly encouraged.

Oxytocin modulates hippocampal perfusion in people at clinical high risk for psychosis

Preclinical and human studies suggest that hippocampal dysfunction is a key factor in the onset of psychosis. People at Clinical High Risk for psychosis (CHR-P) present with a clinical syndrome that can include social withdrawal and have a 20-35% risk of developing psychosis in the next 2 years. Recent research shows that resting hippocampal blood flow is altered in CHR-P individuals and predicts adverse clinical outcomes, such as non-remission/transition to frank psychosis. Previous work in healthy males indicates that a single dose of intranasal oxytocin has positive effects on social function and marked effects on resting hippocampal blood flow. The present study examined the effects of intranasal oxytocin on hippocampal blood flow in CHR-P individuals. In a double-blind, placebo-controlled, crossover design, 30 CHR-P males were studied using pseudo-continuous Arterial Spin Labelling on 2 occasions, once after 40IU intranasal oxytocin and once after placebo. The effects of oxytocin on left hippocampal blood flow were examined in a region-of-interest analysis of data acquired at 22-28 and at 30-36 minutes post-intranasal administration. Relative to placebo, administration of oxytocin was associated with increased hippocampal blood flow at both time points (p = .0056; p = .034), although the effect at the second did not survive adjustment for the effect of global blood flow. These data indicate that oxytocin can modulate hippocampal function in CHR-P individuals and therefore merits further investigation as a candidate novel treatment for this group.

Striatal Glutathione in First-episode Psychosis Patients Measured In Vivo with Proton Magnetic Resonance Spectroscopy

Deficits of brain glutathione (GSH), the most abundant and primary antioxidant in living tissue, and associated redox imbalance are postulated to be implicated in schizophrenia. This pilot clinical study compared the levels of striatal GSH, measured in vivo with proton magnetic resonance spectroscopy (1H MRS) at 3T, in 10 drug-naïve, first-episode psychosis (FEP) patients with those in 9 matched healthy control subjects. The results revealed a significant GSH deficit in FEP patients (0.92 ± 0.24 × 10-3) compared to the healthy control group (1.10 ± 0.10 × 10-3) (U = 25.00, p = 0.02), as well as a positive correlation between GSH levels and the Positive Symptoms subscale of the PANSS in the FEP group (ρ = 0.96; p <0.001). These preliminary findings suggest a possible role of striatal oxidative stress in early-stage psychosis that warrants further scrutiny and confirmation in larger studies.

Inflammatory biomarkers in psychosis and clinical high risk populations

BACKGROUND

Immunological, nutritional, and microbial factors have been implicated in the pathophysiology of schizophrenia, but the interrelationship among measures is understudied. In particular, an increase in the levels of the pro-inflammatory cytokine interleukin-6 (IL-6) is associated with all phases of the illness, and may be associated with other inflammatory markers. Vitamin D is a modulator of the immune system, and LPS antibodies are an indirect measure of gut barrier function. In this study we investigated potential contributing inflammatory mechanisms for IL-6 elevation.

METHODS

We compared the levels of vitamin D, C-reactive protein (CRP), antibodies to lipopolysaccharide (LPS), and IL-6 in children, adolescents and young adults with psychosis (n = 47), individuals at clinical high risk for psychosis (n = 17) and unaffected comparison controls (n = 33). Participants were diagnosed by a psychiatrist, using a structured interview, the MINI-Neuropsychiatric Interview. 25(OH)D was measured in serum using chemiluminescent micro particle immunoassay, and anti-LPS antibodies, CRP and IL-6 levels were measured by ELISA.

RESULTS

IL-6 and C-reactive protein levels were significantly elevated in the psychosis group relative to the unaffected control subjects. In the psychosis group, levels of IL-6 correlated positively with IgA anti-LPS antibodies and negatively correlated with vitamin D.

CONCLUSIONS

Our findings show a significant correlation between IL-6, anti-LPS antibodies and vitamin D deficiency in psychosis, suggesting the existence of multiple potential pathways related to IL-6 elevation in psychosis, and therefore multiple potential strategies for risk mitigation. Collectively these findings support hypotheses regarding interrelated inflammatory contributions to the pathophysiology of psychosis.

Investigation of peripheral complement factors across stages of psychosis

The complement cascade has been proposed to contribute to the pathogenesis of schizophrenia. However, it remains unclear whether peripheral complement levels differ in cases compared to controls, change over the course of illness and whether they are associated with current symptomatology. This study aimed to: i) investigate whether peripheral complement protein levels are altered at different stages of illness, and ii) identify patterns among complement protein levels that predict clinical symptoms. Complement factors C1q, C3 and C4 were quantified in 183 participants [n = 83 Healthy Controls (HC), n = 10 Ultra-High Risk (UHR) for psychosis, n = 40 First Episode Psychosis (FEP), n = 50 Chronic schizophrenia] using Multiplex ELISA. Permutation-based t-tests were used to assess between-group differences in complement protein levels at each of the three illness stages, relative to age- and gender-matched healthy controls. Canonical correlation analysis was used to identify patterns of complement protein levels that correlated with clinical symptoms. C4 was significantly increased in chronic schizophrenia patients, while C3 and C4 were significantly increased in UHR patients. There were no differences in C1q, C3 and C4 in FEP patients when adjusting for BMI. A molecular pattern of increased C4 and decreased C3 was associated with positive and negative symptom severity in the pooled patient sample. Our findings indicate that peripheral complement concentration is increased across specific stages of psychosis and its imbalance may be associated with symptom severity. Given the small sample size of the UHR group, these findings should be regarded as exploratory, requiring replication.

Association between olanzapine treatment and brain cortical thickness and gray/white matter contrast is moderated by cholesterol in psychotic disorders

Altered cortical brain morphology is observed in psychotic disorders. Despite the importance of lipid homeostasis for healthy brain functioning, knowledge about its role in cortical alterations in psychosis is limited. In a sample of patients with psychotic disorders, we investigated the relationship between treatment with olanzapine (OLZ), and cortical thickness and gray/white matter intensity contrast, and the association between these measures and serum lipid levels. We included 33 OLZ users, 19 unmedicated psychotic patients and 76 healthy controls (HC). Data on serum lipids and cortical measures based on MR brain images processed with FreeSurfer were analyzed with General Linear Models. We found that intensity contrast was similar in OLZ users as compared to HC and that the cortex (frontal, orbitofrontal, medial temporal) was thinner in OLZ users (p < 0.05, Bonferroni corrected). An OLZ-specific HDL interaction effect was further found for the pericentral cortical thickness measure (p < 0.05, Bonferroni corrected). Additionally, nominally significant findings indicated similar OLZ-specific interaction effects for cortical thickness in several regions, and an OLZ-specific interaction with LDL for occipital lobe contrast (p < 0.05, uncorrected). Our findings may suggest a drug-related lipid-effect on brain myelination. Experimental studies and replications in different study samples are needed to clarify these complex relationships further.

Correlates of neurocognitive functions in individuals at ultra-high risk for psychosis - A 6-month follow-up study

Cognitive deficits are evident at the prodromal phase of psychosis. It has been noted that brain-derived neurotrophic factor (BDNF) is correlated with cognition in both preclinical and clinical studies. However, to our knowledge, no study has evaluated blood BDNF levels and their association with cognitive impairment in individuals at ultra-high risk for psychosis (UHR). We included 13 individuals at UHR and 30 healthy controls (HC) matched by sex, age, and educational level. Plasma BDNF levels were measured at baseline and 6 months. Neurocognitive functions (executive functions, speed of processing, verbal learning and memory, working memory) were examined at 6 months. Regression analyses were conducted to examine the relationship between BDNF levels and cognitive performance. BDNF levels were lower in UHR group than in HC group both at baseline and at 6 months (P = 0.001, and P = 0.007, respectively). There were no associations between plasma BDNF levels and all of the cognitive domains in both groups. Our findings showed that peripheral BDNF levels were not related to cognitive deficits in UHR and HC groups while the lower BDNF level in the former persisted up to 6 months. Further research is needed in a large sample.

Effects of cannabis use on body mass, fasting glucose and lipids during the first 12 months of treatment in schizophrenia spectrum disorders

While acute cannabis use stimulates appetite, general population studies suggest that chronic use is associated with reduced risk of obesity and other cardiometabolic risk factors. In this study we investigated changes in body mass index (BMI), fasting blood glucose and lipids, and rates of metabolic syndrome risk factors in cannabis users vs. non-users in 109 minimally treated patients with first-episode schizophrenia, schizophreniform or schizo-affective disorder who were treated according to a standardized treatment regime with depot antipsychotic medication over 12 months. Participants underwent repeated urine toxicology tests for cannabis and those testing positive at any time during the study (n = 40), were compared with those who tested negative at all time points (n = 69). There was a significant group*time interaction effect (p = 0.002) with the cannabis negative group showing a greater increase in BMI than the cannabis positive group, after adjusting for age, sex, methamphetamine use and modal dose of antipsychotic. There were no group*time interaction effects for fasting blood glucose or lipids. Post hoc tests indicated significant increases in fasting blood glucose and triglycerides and a decrease in high-density lipoprotein cholesterol for the cannabis negative group, with no significant changes in the cannabis positive group. Rates of metabolic syndrome did not differ significantly between groups, although more cannabis negative patients had elevated waist-circumference at endpoint (p = 0.003). It may be that chronic cannabis use directly suppresses appetite, thereby preventing weight gain in users. However, other indirect effects such as dietary neglect and smoking may be contributory and could explain our findings.

Vitamin D levels, brain volume, and genetic architecture in patients with psychosis

BACKGROUND

Lower vitamin D levels are found in people with schizophrenia and depressive disorders, and also associated with neuroimaging abnormalities such as reduced brain volume in both animals and humans. Reduced whole brain and increased ventricular volume are also systematically reported in schizophrenia. Even though vitamin D deficiency has been proposed as a risk mechanism for schizophrenia there exist no studies to date of the association between vitamin D levels and brain volume in this population. Therefore, we investigated the relationship between vitamin D levels and brain phenotypes in psychotic disorders, and assessed possible interactions with genetic variants in vitamin D receptor (VDR) and other genetic variants that play a role in vitamin D levels in the body.

METHODS

Our sample consisted of 83 psychosis patients and 101 healthy controls. We measured vitamin D levels as serum 25-hydroxyvitamin D. All participants were genotyped and neuroimaging conducted by structural magnetic resonance imaging.

RESULTS

Vitamin D levels were significantly positively associated with peripheral grey matter volume in patients (β 860.6; 95% confidence interval (CI) 333.4-1466, p < .003). A significant interaction effect of BSML marker (rs1544410) was observed to mediate the association between patient status and both white matter volume (β 23603.3; 95% CI 2732.8-48708.6, p < .05) and whole brain volume (β 46670.6, 95% CI 8817.8-93888.3, p < .04). Vitamin D did not predict ventricular volume, which rather was associated with patient status (β 4423.3, 95% CI 1583.2-7267.8p < .002) and CYP24A1 marker (rs6013897) (β 2491.5, 95% CI 269.7-4978.5, p < .04).

CONCLUSIONS

This is the first study of the association between vitamin D levels and brain volume in patients with psychotic disorders that takes into account possible interaction with genetic polymorphisms. The present findings warrant replication in independent samples.

The association between toxoplasma and the psychosis continuum in a general population setting

Toxoplasma gondii infection is associated with increased risk for psychosis. However, the possible association between T. gondii and psychotic-like symptoms in the general adult population is unknown. We investigated whether T. gondii is associated with psychotic-like symptoms and psychosis diagnoses using data from Health 2000, a large cross-sectional health survey of the Finnish general population aged 30 and above. Seropositivity to toxoplasma was defined as a cutoff of 50IU/ml of IgG antibodies. Lifetime psychotic-like symptoms were identified with section G of the Composite International Diagnostic Interview, Munich version (M-CIDI). Symptoms were considered clinically relevant if they caused distress or help-seeking or there were at least three of them. Lifetime psychotic disorders were screened from the sample and were diagnosed with DSM-IV using SCID-I interview and information from medical records. All data were available for 5906 participants. We adjusted for variables related to T. gondii seropositivity (age, gender, education, region of residence, cat ownership, and C-reactive protein measuring inflammation) in regression models. We found that T. gondii seropositivity was significantly associated with clinically relevant psychotic-like symptoms (OR 1.77, p=0.001) and with the number of psychotic-like symptoms (IRR=1.55, p=0.001). The association between toxoplasma and diagnosed psychotic disorders did not reach statistical significance (OR 1.45 for schizophrenia). In a large sample representing the whole Finnish adult population, we found that serological evidence of toxoplasma infection predicted psychotic-like symptoms, independent of demographic factors and levels of C-reactive protein. Toxoplasma infection may be a risk factor for manifestation of psychotic-like symptoms.

Th17/T regulator cell balance and NK cell numbers in relation to psychosis liability and social stress reactivity

BACKGROUND

Psychotic disorders are characterized by a deranged immune system, including altered number and function of Natural Killer (NK) and T cells. Psychotic disorders arise from an interaction between genetic vulnerability and exposure to environmental risk factors. Exposure to social adversity during early life is particularly relevant to psychosis risk and is thought to increase reactivity to subsequent minor daily social stressors. Virtual reality allows controlled experimental exposure to virtual social stressors.

AIM

To investigate the interplay between social adversity during early life, cell numbers of NK cells and T helper subsets and social stress reactivity in relation to psychosis liability.

METHODS

Circulating numbers of Th1, Th2, Th17, T regulator and NK cells were determined using flow cytometry in 80 participants with low psychosis liability (46 healthy controls and 34 siblings) and 53 participants with high psychosis liability (14 ultra-high risk (UHR) patients and 39 recent-onset psychosis patients), with and without the experience of childhood trauma. We examined if cell numbers predicted subjective stress when participants were exposed to social stressors (crowdedness, hostility and being part of an ethnic minority) in a virtual reality environment.

RESULTS

There were no significant group differences in Th1, Th2, Th17, T regulator and NK cell numbers between groups with a high or low liability for psychosis. However, in the high psychosis liability group, childhood trauma was associated with increased Th17 cell numbers (p = 0.028). Moreover, in the high psychosis liability group increased T regulator and decreased NK cell numbers predicted stress experience during exposure to virtual social stressors (p = 0.015 and p = 0.009 for T regulator and NK cells, respectively).

CONCLUSION

A deranged Th17/T regulator balance and a reduced NK cell number are associated intermediate biological factors in the relation childhood trauma, psychosis liability and social stress reactivity.

Blood-Based Protein Changes in Childhood Are Associated With Increased Risk for Later Psychotic Disorder: Evidence From a Nested Case-Control Study of the ALSPAC Longitudinal Birth Cohort

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. Protein expression levels at age 11 were compared between individuals who developed PD at age 18 (n = 37) with population-based age-matched controls (n = 38). Sixty out of 181 plasma proteins profiled were found to be differentially expressed (P < .05) in children with an outcome of the PD. Thirty-four of these proteins were found to be differentially expressed following correction for multiple comparisons. Pathway analysis implicated the complement and coagulation cascade. A second, targeted proteomic approach was used to verify these findings in age 11 plasma from subjects who reported psychotic experiences at age 18 (n = 40) in comparison to age-matched controls (n = 66). Our findings indicate that the complement and coagulation system is dysregulated in the blood during childhood before the development of the PD.

Blood Platelet 5-Hydroxytryptamine Levels in Psychiatric Patients

The interest of 5-hydroxytryptamine (5HT) for psychiatry arose originally from Gaddum's (8, 9) observation that its peripheral pharmacological actions were antagonized in a highly specific manner by a low concentration of lysergic acid diethylamide (LSD). This led to the hypothesis that the hallucinogenic action of LSD was due to its antagonism to 5HT in the central nervous system (Woolley and Shaw, 21; Gaddum, 7). However, Cerletti and Rothlin (5) subsequently found that brom-LSD, which is not a hallucinogen, was an equally potent antagonist of the peripheral actions of 5HT.

Potential diagnostic markers of olanzapine efficiency for acute psychosis: a focus on peripheral biogenic amines

BACKGROUND

Biomarkers are now widely used in many fields of medicine, and the identification of biomarkers that predict antipsychotic efficacy and adverse reactions is a growing area of psychiatric research. Monoamine molecules of the peripheral bloodstream are possible prospective biomarkers based on a growing body of evidence indicating that they may reflect specific changes in neurotransmitters in the brain. The aim of this study was to detect peripheral biogenic amine indicators of patients with acute psychosis and to test the correlations between the biological measures studied and the psychopathological status of the patients.

METHODS

This research included 60 patients with acute psychosis treated with olanzapine (n = 30) or haloperidol (n = 30). Here, we measured biogenic amine indicators, including mRNA levels of dopamine receptor D4 (DRD4) and the serotonin 2A receptor (5HTR2A), in peripheral blood mononuclear cells (PBMCs) using quantitative real-time polymerase chain reaction and serum dopamine concentrations by enzyme linked immunosorbent assay (ELISA). Psychopathological status was evaluated using psychometric scales. The assessments were conducted prior to and after 14 and 28 days of treatment.

RESULTS

The administration of haloperidol, but not olanzapine, up-regulated 5HTR2A mRNA in a linear manner, albeit without statistical significance (p = 0.052). Both drugs had non-significant effects on DRD4 mRNA levels. Nevertheless, a positive correlation was found between DRD4 and 5HTR2A mRNA levels over a longitudinal trajectory, suggesting co-expression of the two genes. A significant positive correlation was observed between 5HTR2A mRNA levels and total Positive and Negative Syndrome Scale (PANSS) scores in both groups of patients before treatment. A significant correlation between baseline 5HTR2A mRNA levels and PANSS scores on days 14 and 28 of treatment remained for patients treated with olanzapine only. Moreover, a significant positive correlation was observed between blood serum dopamine levels and scores on extrapyramidal symptom scales in the olanzapine group.

CONCLUSIONS

The DRD4 and 5HTR2A genes are co-expressed in PBMCs during antipsychotic administration. Despite a correlation between the studied biogenic amine indicators and the psychopathological status of patients, reliable biomarkers of treatment response could not be determined.

Vitamin D Supplementation in Chronic Schizophrenia Patients Treated with Clozapine: A Randomized, Double-Blind, Placebo-controlled Clinical Trial

BACKGROUND

While accumulating evidence suggests that vitamin D deficiency may be involved in the risk to develop schizophrenia and its outcome, there are no studies on vitamin D supplementation in this context. We sought to assess the effect of vitamin D supplementation on psychiatric, cognitive and metabolic parameters in chronic clozapine-treated schizophrenia patients.

METHODS

This eight-week, randomized, double-blind, placebo-controlled clinical trial, recruited schizophrenia patients who had been maintained on clozapine treatment for at least 18weeks and had low levels of vitamin D (<75nmol/l) and total PANSS scores >70 (to ascertain the presence of residual symptoms). Patients were randomly allocated to either weekly oral drops of vitamin D (14,000IU) or placebo and subsequently assessed at two-week intervals for psychosis severity, mood, cognition and metabolic profile.

RESULTS

Twenty four patients were randomly assigned to vitamin D (aged 39.4±9.6years, 75% males) and the other 23 patients to the placebo arm (aged 42.5±11.2years, 60.9% males). After eight weeks, the vitamin D group exhibited a significant increase in vitamin D levels (31.4 vs -0.4nmol/l, p<0.0001). There was no significant effect of vitamin D on psychotic, depressive or metabolic parameters. However, in the vitamin D group, there was a trend towards improved cognition (effect size=0.17, significance lost following Bonferroni correction).

CONCLUSIONS

Vitamin D supplementation was associated with a trend towards improved cognition, but did not affect psychosis, mood or metabolic status. It is possible that the robust decrease in the PANSS scores in both groups may have obscured an effect of vitamin D supplementation.

Plasma nesfatin 1 level in patients with first attack psychosis

OBJECTIVES

This study aimed to investigate the possible relationship between plasma concentrations of nesfatin 1 and first attack psychosis.

METHODS

Totally, 32 patients with the first episode psychosis and 33 randomly selected weight- and body mass index-matched healthy volunteers admitted to Mustafa Kemal University, Faculty of Medicine, Training and Research Hospital, Psychiatry outpatient clinic were included. Healthy control subjects were matched in terms of weight and body mass index (BMI). The Positive and Negative Syndrome Scale (PANNS) was applied to the patient group. The enzyme-linked immunosorbent assay (ELISA) method was used to measure plasma nesfatin 1 levels.

RESULTS

The mean nesfatin 1 level was lower in the patients with the first attack psychosis (0.60 ± 1.00 ng/mL) than in the control group (0.75 ± 1.07 ng/mL).However it did not reach statistical significance (t = -0.567, p = 0.573). There was no statistically significant correlation between plasma nesfatin 1 levels and total PANNS scores in the patient group (r = -0.262, p = 0.148).

CONCLUSION

Our study was the first to investigate the nesfatin 1 levels in patients with the first episode psychosis. Based on our study results, nesfatin 1 might be related to some central nervous system pathologies, including the severity of a psychiatric disorder; however, further large-scale studies are required to establish a conclusion (Tab. 1, Ref. 21).

Longitudinal assessment of brain-derived neurotrophic factor in Sardinian psychotic patients (LABSP): a protocol for a prospective observational study

INTRODUCTION

Brain-derived neurotrophic factor (BDNF) plays a crucial role in neurodevelopment, synaptic plasticity and neuronal function and survival. Serum and plasma BDNF levels are moderately, but consistently, decreased in patients with schizophrenia (SCZ) compared with healthy controls. There is a lack of knowledge, however, on the temporal manifestation of this decline. Clinical, illness course and treatment factors might influence the variation of BDNF serum levels in patients with psychosis. In this context, we propose a longitudinal study of a cohort of SCZ and schizophrenic and schizoaffective disorder (SAD) Sardinian patients with the aim of disentangling the relationship between peripheral BDNF serum levels and changes of psychopathology, cognition and drug treatments.

METHODS AND ANALYSIS

Longitudinal assessment of BDNF in Sardinian psychotic patients (LABSP) is a 24-month observational prospective cohort study. Patients with SAD will be recruited at the Psychiatry Research Unit of the Department of Medical Science and Public Health, University of Cagliari and University of Cagliari Health Agency, Cagliari, Italy. We will collect BDNF serum levels as well as sociodemographic, psychopathological and neurocognitive measures. Structured, semistructured and self-rating assessment tools, such as the Positive and Negative Syndrome Scale for psychopathological measures and the Brief Assessment of Cognition in Schizophrenia for cognitive function, will be used.

ETHICS AND DISSEMINATION

This study protocol was approved by the University of Cagliari Health Agency Ethics Committee (NP2016/5491). The study will be conducted in accordance with the principles of good clinical practice, in the Declaration of Helsinki in compliance with the regulations. Participation will be voluntary and written informed consent will be obtained for each participant upon entry into the study. We plan to disseminate the results of our study through conference presentations and publication in international peer-reviewed journals. Access to raw data will be available in anonymised form upon request to the corresponding author.

Association of sFlt-1 and worsening psychopathology in relatives at high risk for psychosis: A longitudinal study

BACKGROUND

Angiogenic dysfunction and abnormalities in psychopathology and brain structure have been reported in schizophrenia, but their relationships are mostly unknown. We recently demonstrated that sFlt-1, anti-angiogenic factor, was significantly elevated in patients at familial high-risk for psychosis (FHR). We hypothesized that elevated sFlt-1 correlates with baseline and longitudinal changes in psychopathology, cognition, and brain structure.

METHODS

Plasma sFlt-1 in FHR (n=35) and HC (n=39) was obtained at baseline. Schizotypal, cognitive, soft neurologic signs, and structural brain imaging (1.5T T1-weighted MRI, FreeSurfer software) measures were obtained in both groups. Longitudinal clinical and brain structural measures were obtained in a subgroup of FHR patients. Baseline data analysis used correlations between sFlt-1 and clinical/imaging measures and adjusted for multiple corrections. Linear mixed-effects models described differences in trajectories between high sFlt-1 and low sFlt-1.

RESULTS

Baseline sFlt-1 was significantly correlated with soft neurologic signs (r=0.27, p=0.02) and right entorhinal volume (r=0.50, p=0.02), but not other baseline clinical/brain structural measures. Longitudinal examination of the FHR group (sFlt-1 high, n=14; sFlt-1 low, n=14) demonstrated that high sFlt-1 was significantly associated with worsening schizotypal symptoms (t=2.4, p=0.018). Reduced right hippocampal/parahippocampal volume/thickness trajectories were observed in high versus low sFlt-1 groups.

CONCLUSIONS

The findings from this FHR study demonstrate that peripheral markers of angiogenic dysfunction can predict longitudinal clinical and brain structural changes. Also, these findings further support the hypothesis of altered microvascular circulation in schizophrenia and those at risk.

Serum S100B: A proxy marker for grey and white matter status in the absence and presence of (increased risk of) psychotic disorder?

S100B is a protein with dose-dependent neurotrophic and neurotoxic effects. Whether S100B in psychotic disorder mirrors pathophysiological mechanisms (which elicit exacerbation of disease) or compensatory action is unclear, as is its validity as a proxy marker for brain status. Insight may be gained by examining associations between serum S100B and indices of grey (cortical thickness (CT)) and white matter (fractional anisotropy (FA)), in relation to the absence or presence of (increased risk of) psychotic disorder. Blood samples and cerebral magnetic resonance imaging (MRI) scans were acquired in 32 patients with psychotic disorder, 44 non-psychotic siblings of patients with psychotic disorder and 26 controls. Interactions between S100B and group were examined in separate models of CT and FA measures with multilevel regression analyses weighted for number of vertices and voxels (i.e. units of volume) respectively. All analyses were adjusted for sex, age, body mass index (BMI), scan sequence, handedness and highest level of education. Neither CT nor FA was associated with S100B. There were no significant S100B × group interactions (CT: χ² = 0.044, p = 0.978; FA: χ2 = 3.672, p = 0.159). No evidence was present for S100B as a proxy marker of grey or white matter status. The association between S100B and brain measures was not moderated by psychosis risk.

Prevalence and clinical characteristics of serum neuronal cell surface antibodies in first-episode psychosis: a case-control study

BACKGROUND

Psychosis is a common presenting feature in antibody-mediated encephalitis, for which prompt recognition and treatment usually leads to remission. We aimed to investigate whether people with circumscribed schizophrenia-like illnesses have such antibodies-especially antibodies against the N-methyl-D-aspartate receptor (NMDAR)-more commonly than do healthy controls.

METHODS

We recruited patients aged 14-35 years presenting to any of 35 mental health services sites across England with first-episode psychosis, less than 6 weeks of treatment with antipsychotic medication, and a score of 4 or more on at least one selected Positive and Negative Syndrome Scale (PANSS) item. Patients and controls provided venous blood samples. We completed standardised symptom rating scales (PANSS, ACE-III, GAF) at baseline, and tested serum samples for antibodies against NMDAR, LGI1, CASPR2, the GABAA receptor, and the AMPA receptor using live cell-based assays. Treating clinicians assessed outcomes of ICD diagnosis and functioning (GAF) at 6 months. We included healthy controls from the general population, recruited as part of another study in Cambridge, UK.

FINDINGS

Between Feb 1, 2013, and Aug 31, 2014, we enrolled 228 patients with first-episode psychosis and 105 healthy controls. 20 (9%) of 228 patients had serum antibodies against one or more of the neuronal cell surface antibodies compared with four (4%) of 105 controls (unadjusted odds ratio 2·4, 95% CI 0·8-7·3). These associations remained non-significant when adjusted for current cigarette smoking, alcohol consumption, and illicit drug use. Seven (3%) patients had NMDAR antibodies compared with no controls (p=0·0204). The other antibodies did not differ between groups. Antibody-positive patients had lower PANSS positive, PANSS total, and catatonia scores than did antibody-negative patients. Patients had comparable scores on other PANSS items, ACE-III, and GAF at baseline, with no difference in outcomes at 6 months.

INTERPRETATION

Some patients with first-episode psychosis had antibodies against NMDAR that might be relevant to their illness, but did not differ from patients without NMDAR antibodies in clinical characteristics. Our study suggests that the only way to detect patients with these potentially pathogenic antibodies is to screen all patients with first-episode psychosis at first presentation.

FUNDING

Medical Research Council.

Low vitamin D is associated with negative and depressive symptoms in psychotic disorders

BACKGROUND

There are indications that low S-25(OH)D is associated with increased disease severity in psychotic disorder. Our first aim was to investigate the relations between low S-25(OH)D and positive, negative and depressive symptoms. Our second aim was to explore if associations between S-25(OH)D and symptoms were influenced by levels of inflammatory markers.

METHODS

Participants (N=358) with a medical history of one or more psychotic episodes were recruited. Current symptomatology was assessed by The Structured Interview for the Positive and Negative Syndrome Scaleanalyzed by a five-factor model. The Calgary Depression Scale for Schizophrenia was used to assess depression and suicidal ideation. Blood samples were analyzed for S-25(OH)D, CRP, sTNF-R1, IL-Ra and OPG. We performed bivariate correlations and multiple regression models to evaluate the effect of S-25(OH)D on the outcomes.

RESULTS

Low S-25(OH)D was significantly associated with negative symptoms (adjusted R²=0.113, F(6,357)=8.58, p<0.001) and with depression (adjusted R²=0.045, F(4,357)=5.233, p<0.001) when adjusting for possible confounding factors (i.e. gender, education, diagnose, hospitalization status, ethnicity, season and thyroid status). CRP was correlated with both S-25(OH)D (rho=-0.13, p=0.02) and negative symptoms (rho=0.14, p=0.01), but did not act as a mediator. The correlations between S-25(OH)D and the inflammatory markers sTNF-R1, IL-Ra and OPG were not significant.

CONCLUSION

There is a strong association between low S-25(OH)D and higher negative and depressive symptoms in psychotic disorders. Randomized controlled trials should be performed to investigate the effect of vitamin D supplementation as adjuvant treatment strategy in patients with prominent negative or depressive symptoms.

It is feasible and effective to help patients with severe mental disorders to quit smoking: An ecological pragmatic clinical trial with transdermal nicotine patches and varenicline

Despite the proven association between smoking and high rates of medical morbidity and reduced life expectancy in people with severe mental disorders (SMD), their smoking rates do not decline as they do in the general population. We carried out a non-randomized, open-label, prospective, 9-month follow-up multicentre trial to investigate the clinical efficacy, safety and tolerability of a 12-week smoking cessation programme for patients with SMD in the community under real-world clinical conditions. Eighty-two adult outpatients with schizophrenic/bipolar disorder smoking ≥15 cigarettes/day were assigned by shared decision between doctors and patients to transdermal nicotine patches (TNP) [36(46.2%)] or varenicline [39(50%)]. Short-term efficacy: The 12-week 7-day smoking cessation (self-reported cigarettes/day=0 and breath carbon monoxide levels≤9ppm) prevalence was 49.3%, without statistically significant differences between medications (TNP 50.0% vs varenicline 48.6%, chi-square=0.015, p=1.000). Long-term efficacy: At weeks 24 and 36, 41.3 and 37.3% of patients were abstinent, with no statistically significant differences between treatments. Safety and Tolerability: no patients made suicide attempts/required hospitalization. There was no worsening on the psychometric scales. Patients significantly increased weight [TNP 1.1(2.8) vs varenicline 2.5(3.3), p=0.063], without significant changes in vital signs/laboratory results, except significant decreases in alkaline phosphatase and low-density lipoprotein-cholesterol levels in the varenicline group. Patients under varenicline more frequently presented nausea/vomiting (p<0.0005), patients under TNP experienced skin reactions more frequently (p=0.002). Three patients under varenicline had elevated liver enzymes. In conclusion, we have demonstrated that in real-world clinical settings it is feasible and safe to help patients with stabilized severe mental disorders to quit smoking.

Differential expression of the inflammation marker IL12p40 in the at-risk mental state for psychosis: a predictor of transition to psychotic disorder?

BACKGROUND

The identification of biomarkers of transition from the at-risk mental state (ARMS) to psychotic disorder is important because early treatment of psychosis is associated with improved outcome. Increasing evidence points to an inflammatory contribution to psychosis. We questioned whether raised levels of plasma inflammatory markers predict transition from ARMS to psychotic disorder and whether any such predictors could be reduced by omega-3 (ω-3) polyunsaturated fatty acids (PUFAs).

METHODS

We measured the levels of 40 neuroinflammation biomarkers using a commercially available immunoassay kit. Firstly, we compared inflammatory markers in subjects in the ARMS who transitioned to psychotic disorder (n = 11) compared to subjects who did not (n = 28). Then we compared inflammatory markers in all subjects before and after ω-3 PUFA treatment (n = 40).

RESULTS

Our data provides preliminary evidence that elevations in the baseline plasma levels of the inflammatory marker IL12/IL23p40 are associated with transition from ARMS to psychotic disorder. IL12/IL23p40 levels did not change following 12 weeks administration of ω-3 PUFAs. These findings provide evidence that elevated plasma IL12/IL23p40 is a potential biomarker of increased risk for transition to psychotic disorder.

CONCLUSION

Further studies are required to confirm and extend this finding. Our results do not provide support for the possibility that administration of ω-3 PUFAs act to reduced transition to psychotic disorder by reducing blood levels of IL12/IL23p40.

TRIAL REGISTRATION

ClinicalTrials.gov, a service of the U.S. National Institutes of Health, Identifier: NCT00396643 , last updated December 20, 2007. Retrospectively registered.

Impaired fornix-hippocampus integrity is linked to peripheral glutathione peroxidase in early psychosis

Several lines of evidence implicate the fornix-hippocampus circuit in schizophrenia. In early-phase psychosis, this circuit has not been extensively investigated and the underlying mechanisms affecting the circuit are unknown. The hippocampus and fornix are vulnerable to oxidative stress at peripuberty in a glutathione (GSH)-deficient animal model. The purposes of the current study were to assess the integrity of the fornix-hippocampus circuit in early-psychosis patients (EP), and to study its relationship with peripheral redox markers. Diffusion spectrum imaging and T1-weighted magnetic resonance imaging (MRI) were used to assess the fornix and hippocampus in 42 EP patients compared with 42 gender- and age-matched healthy controls. Generalized fractional anisotropy (gFA) and volumetric properties were used to measure fornix and hippocampal integrity, respectively. Correlation analysis was used to quantify the relationship of gFA in the fornix and hippocampal volume, with blood GSH levels and glutathione peroxidase (GPx) activity. Patients compared with controls exhibited lower gFA in the fornix as well as smaller volume in the hippocampus. In EP, but not in controls, smaller hippocampal volume was associated with high GPx activity. Disruption of the fornix-hippocampus circuit is already present in the early stages of psychosis. Higher blood GPx activity is associated with smaller hippocampal volume, which may support a role of oxidative stress in disease mechanisms.