Dysconnectivity in Schizophrenia Revisited: Abnormal Temporal Organization of Dynamic Functional Connectivity in Patients With a First Episode of Psychosis

BACKGROUND AND HYPOTHESIS

Abnormal functional connectivity between brain regions is a consistent finding in schizophrenia, including functional magnetic resonance imaging (fMRI) studies. Recent studies have highlighted that connectivity changes in time in healthy subjects. We here examined the temporal changes in functional connectivity in patients with a first episode of psychosis (FEP). Specifically, we analyzed the temporal order in which whole-brain organization states were visited.

STUDY DESIGN

Two case-control studies, including in each sample a subgroup scanned a second time after treatment. Chilean sample included 79 patients with a FEP and 83 healthy controls. Mexican sample included 21 antipsychotic-naïve FEP patients and 15 healthy controls. Characteristics of the temporal trajectories between whole-brain functional connectivity meta-states were examined via resting-state functional MRI using elements of network science. We compared the cohorts of cases and controls and explored their differences as well as potential associations with symptoms, cognition, and antipsychotic medication doses.

STUDY RESULTS

We found that the temporal sequence in which patients' brain dynamics visited the different states was more redundant and segregated. Patients were less flexible than controls in changing their network in time from different configurations, and explored the whole landscape of possible states in a less efficient way. These changes were related to the dose of antipsychotics the patients were receiving. We replicated the relationship with antipsychotic medication in the antipsychotic-naïve FEP sample scanned before and after treatment.

CONCLUSIONS

We conclude that psychosis is related to a temporal disorganization of the brain's dynamic functional connectivity, and this is associated with antipsychotic medication use.

Anti-stigma advocacy for health professionals: a systematic review

BACKGROUND

Many anti-stigma programs for healthcare workers already exist however there is less research on the effectiveness of training in skills for health professionals to counter stigma and its impacts on patients.

AIMS

The objective of this study was to examine the theory base, content, delivery, and outcomes of interventions for healthcare professionals which aim to equip them with knowledge and skills to aid patients to mitigate stigma and discrimination and their health impacts.

METHODS

Five electronic databases and grey literature were searched. Data were screened by two independent reviewers, conflicts were discussed. Quality appraisal was realized using the ICROMS tool. A narrative synthesis was carried out.

RESULTS

The final number of studies was 41. In terms of theory base, there are three strands - responsibility as part of the professional role, correction of wrongful practices, and collaboration with local communities. Content focusses either on specific groups experiencing health-related stigma or health advocacy in general.

CONCLUSIONS

Findings suggest programs should link definitions of stigma to the role of the professional. They should be developed following a situational analysis and include people with lived experience. Training should use interactive delivery methods. Evaluation should include follow-up times that allow examination of behavioural change. PROSPERO, ID: CRD42020212527.

The enduring gap in educational attainment in schizophrenia according to the past 50 years of published research: a systematic review and meta-analysis

BACKGROUND

Educational attainment is associated with wellbeing and health, but patients with schizophrenia achieve lower levels of education than people without. Several effective interventions can ameliorate this situation. However, the magnitude of the education gap in schizophrenia and its change over time are unclear. We aimed to reconstruct the trajectories of educational attainment in patients with schizophrenia and, if reported, their healthy comparator controls.

METHODS

We did a systematic review and meta-analysis including all studies reporting on patients with schizophrenia (of mean age ≥18 years) and describing the number of years of education of the participants, with or without healthy controls. There were no other design constraints on studies. We excluded studies that included only patients with other schizophrenia spectrum disorders and studies that did not specify the number of years of education of the participants. 22 reviewers participated in retrieving data from a search in PubMed and PsycINFO (Jan 1, 1970, to Nov 24, 2020). We estimated the birth date of participants from their mean age and publication date, and meta-analysed these data using random-effects models, focusing on educational attainment, the education gap, and changes over time. The primary outcome was years of education. The protocol was registered on PROSPERO (CRD42020220546).

FINDINGS

From 32 593 initial references, we included 3321 studies reporting on 318 632 patients alongside 138 675 healthy controls (170 941 women and 275 821 men from studies describing sex or gender; data on ethnicity were not collected). Patients' educational attainment increased over time, mirroring that of controls. However, patients with schizophrenia in high-income countries had 19 months less education than controls (-1·59 years, 95% CI -1·66 to -1·53; p<0·0001), which is equivalent to a Cohen's d of -0·56 (95% CI -0·58 to -0·54) and implies an odds ratio of 2·58 for not completing 12 years of education (ie, not completing secondary education) for patients compared with controls. This gap remained stable throughout the decades; the rate of change in number of total years of education in time was not significant (annual change: 0·0047 years, 95% CI -0·0005 to 0·0099; p=0·078). For patients in low-income and middle-income countries, the education gap was significantly smaller than in high-income countries (smaller by 0·72 years, 0·85 to 0·59; p<0·0001), yet there was evidence that this gap was widening over the years, approaching that of high-income countries (annual change: -0·024 years, -0·037 to -0·011; p=0·0002).

INTERPRETATION

Patients with schizophrenia have faced persistent inequality in educational attainment in the last century, despite advances in psychosocial and pharmacological treatment. Reducing this gap should become a priority to improve their functional outcomes.

FUNDING

Ciencia y Tecnología para el Desarrollo (CYTED) to the Latin American Network for the Study of Early Psychosis (ANDES).

The incidence of non-affective psychotic disorders in Chile between 2005 and 2018: results from a national register of over 30 000 cases

BACKGROUND

Evidence suggests the incidence of non-affective psychotic disorders (NAPDs) varies across persons and places, but data from the Global South is scarce. We aimed to estimate the treated incidence of NAPD in Chile, and variance by person, place and time.

METHODS

We used national register data from Chile including all people, 10-65 years, with the first episode of NAPD (International Classification of Diseases, Tenth Revision: F20-F29) between 1 January 2005 and 29 August 2018. Denominators were estimated from Chilean National Census data. Our main outcome was treated incidence of NAPD and age group, sex, calendar year and regional-level population density, multidimensional poverty and latitude were exposures of interest.

RESULTS

We identified 32 358 NAPD cases [12 136 (39.5%) women; median age-at-first-contact: 24 years (interquartile range 18-39 years)] during 171.1 million person-years [crude incidence: 18.9 per 100 000 person-years; 95% confidence interval (CI) 18.7-19.1]. Multilevel Poisson regression identified a strong age-sex interaction in incidence, with rates peaking in men (57.6 per 100 000 person-years; 95% CI 56.0-59.2) and women (29.5 per 100 000 person-years; 95% CI 28.4-30.7) between 15 and 19 years old. Rates also decreased (non-linearly) over time for women, but not men. We observed a non-linear association with multidimensional poverty and latitude, with the highest rates in the poorest regions and those immediately south of Santiago; no association with regional population density was observed.

CONCLUSION

Our findings inform the aetiology of NAPDs, replicating typical associations with age, sex and multidimensional poverty in a Global South context. The absence of association with population density suggests this risk may be context-dependent.

Functional Dysconnectivity in Ventral Striatocortical Systems in 22q11.2 Deletion Syndrome

22q11.2 deletion syndrome (22q11.2DS) is a genetic neurodevelopmental disorder that represents one of the greatest known risk factors for psychosis. Previous studies in psychotic subjects without the deletion have identified a dopaminergic dysfunction in striatal regions, and dysconnectivity of striatocortical systems, as an important mechanism in the emergence of psychosis. Here, we used resting-state functional MRI to examine striatocortical functional connectivity in 22q11.2DS patients. We used a 2 × 2 factorial design including 125 subjects (55 healthy controls, 28 22q11.2DS patients without a history of psychosis, 10 22q11.2DS patients with a history of psychosis, and 32 subjects with a history of psychosis without the deletion), allowing us to identify network effects related to the deletion and to the presence of psychosis. In line with previous results from psychotic patients without 22q11.2DS, we found that there was a dorsal to ventral gradient of hypo- to hyperstriatocortical connectivity related to psychosis across both patient groups. The 22q11.2DS was additionally associated with abnormal functional connectivity in ventral striatocortical networks, with no significant differences identified in the dorsal system. Abnormalities in the ventral striatocortical system observed in these individuals with high genetic risk to psychosis may thus reflect a marker of illness risk.

Abnormal nodal and global network organization in resting state functional MRI from subjects with the 22q11 deletion syndrome

The 22q11 deletion syndrome is a genetic disorder associated with a high risk of developing psychosis, and is therefore considered a neurodevelopmental model for studying the pathogenesis of schizophrenia. Studies have shown that localized abnormal functional brain connectivity is present in 22q11 deletion syndrome like in schizophrenia. However, it is less clear whether these abnormal cortical interactions lead to global or regional network disorganization as seen in schizophrenia. We analyzed from a graph-theory perspective fMRI data from 40 22q11 deletion syndrome patients and 67 healthy controls, and reconstructed functional networks from 105 brain regions. Between-group differences were examined by evaluating edge-wise strength and graph theoretical metrics of local (weighted degree, nodal efficiency, nodal local efficiency) and global topological properties (modularity, local and global efficiency). Connectivity strength was globally reduced in patients, driven by a large network comprising 147 reduced connections. The 22q11 deletion syndrome network presented with abnormal local topological properties, with decreased local efficiency and reductions in weighted degree particularly in hub nodes. We found evidence for abnormal integration but intact segregation of the 22q11 deletion syndrome network. Results suggest that 22q11 deletion syndrome patients present with similar aberrant local network organization as seen in schizophrenia, and this network configuration might represent a vulnerability factor to psychosis.

Predictors of clozapine discontinuation at 2 years in treatment-resistant schizophrenia

INTRODUCTION

Little is known about predictors of clinical response to clozapine treatment in treatment-resistant psychosis. Most published cohorts are small, providing inconsistent results. We aimed to identify baseline clinical predictors of future clinical response in patients who initiate clozapine treatment, mainly focusing on the effect of age, duration of illness, baseline clinical symptoms and homelessness.

METHODOLOGY

Retrospective cohort of patients with treatment-resistant schizophrenia, aged between 15 and 60 years, that initiated clozapine between 2014 and 2017. Sociodemographic characteristics, years from illness diagnosis, and clinical presentation before the initiation of clozapine were collected and analyzed. All-cause discontinuation at two years follow-up was used as the primary measure of clozapine response.

RESULTS

261 patients were included with a median age at illness diagnosis of 23 years old (IQR 19-29) and a median age at clozapine initiation of 25 (IQR: 21-33). 72.33% (183/253) continued clozapine after two years follow-up. Being homeless was associated to higher clozapine non-adherence, with an OR of 2.78 (95%CI 1.051-7.38) (p = 0.039, controlled by gender). Older age at clozapine initiation and longer delay from first schizophrenia diagnosis to clozapine initiation were also associated with higher clozapine non-adherence, with each year increasing the odds of discontinuation by 1.043 (95%CI 1.02-1.07; p = 0.001) and OR 1.092 (95%CI 1.01-1.18;p = 0.032) respectively.

CONCLUSION

Starting clozapine in younger patients or shortly after schizophrenia diagnosis were associated with better adherence.

Structural brain abnormalities in schizophrenia in adverse environments: examining the effect of poverty and violence in six Latin American cities

BACKGROUND

Social and environmental factors such as poverty or violence modulate the risk and course of schizophrenia. However, how they affect the brain in patients with psychosis remains unclear.

AIMS

We studied how environmental factors are related to brain structure in patients with schizophrenia and controls in Latin America, where these factors are large and unequally distributed.

METHOD

This is a multicentre study of magnetic resonance imaging in patients with schizophrenia and controls from six Latin American cities. Total and voxel-level grey matter volumes, and their relationship with neighbourhood characteristics such as average income and homicide rates, were analysed with a general linear model.

RESULTS

A total of 334 patients with schizophrenia and 262 controls were included. Income was differentially related to total grey matter volume in both groups (P = 0.006). Controls showed a positive correlation between total grey matter volume and income (R = 0.14, P = 0.02). Surprisingly, this relationship was not present in patients with schizophrenia (R = -0.076, P = 0.17). Voxel-level analysis confirmed that this interaction was widespread across the cortex. After adjusting for global brain changes, income was positively related to prefrontal cortex volumes only in controls. Conversely, the hippocampus in patients with schizophrenia, but not in controls, was relatively larger in affluent environments. There was no significant correlation between environmental violence and brain structure.

CONCLUSIONS

Our results highlight the interplay between environment, particularly poverty, and individual characteristics in psychosis. This is particularly important for harsh environments such as low- and middle-income countries, where potentially less brain vulnerability (less grey matter loss) is sufficient to become unwell in adverse (poor) environments.

Health State Utility Values in Schizophrenia: A Systematic Review and Meta-Analysis

OBJECTIVES

Patient preferences are increasingly important in informing clinical and policy decisions. Health-state utility values (HSUVs) are quantitative measures of people's preferences over different health states. In schizophrenia, there is no clarity about HSUVs across the symptoms' severity spectrum. This meta-analysis aims to synthesize the literature on HSUVs in people with schizophrenia.

METHODS

We searched Medline, PsycInfo, Embase, EconLit, The Cochrane Library, and specialized databases. The studies reporting HSUVs in people with schizophrenia were selected and pooled in a random-effects meta-analysis. The primary outcome was the mean HSUV obtained from participants.

RESULTS

A total of 54 studies involving 87 335 participants were included. The pooled estimate using direct elicitation was a mean HSUV of 0.79 (95% CI: 0.70-0.88) for mild symptomatic states, 0.69 (95% CI: 0.54-0.85) in moderate states, and 0.34 (95% CI: 0.13-0.56) in severe states. Studies using indirect techniques resulted in a pooled mean HSUV of 0.73 (95% CI: 0.67-0.78) applying the EuroQol 5-dimension, 0.66 (95% CI: 0.62-0.71) in the Short-Form 6-dimension, and 0.59 (95% CI: 0.57-0.61) using the Quality of Well-Being scale. All the estimates resulted in considerable heterogeneity, partially reduced by meta-regression.

CONCLUSION

Our findings suggest that the severity of psychotic symptoms has an important effect on HSUVs in schizophrenia, with values mirroring patients with disabling physical conditions such as cancer and stroke. Decision makers should be aware of these results when including people's preferences in trials, models, and policy decisions.

High prevalence of metabolic alterations in Latin American patients at initial stages of psychosis

AIM

Studies conducted in the United States have highlighted a higher prevalence of metabolic alterations (MA) in Latino population and Latino psychotic patients. Metabolic risk in psychosis is known to be present from initial stages of the disease. To better characterize this population, we explored the prevalence of MA and metabolic syndrome (MS) in early psychosis patients in a Latin American country.

METHODS

Transversal, observational study comparing the prevalence of MA and MS in patients with early psychosis from an outpatient program in Chile (n = 148) with a community representative sample from the 2009-2010 National Health Survey (n = 568). ANOVA and regression analysis were performed obtaining odds ratio for MA and MS.

RESULTS

The prevalence of MS was 44.7% in patients compared to 11.4% in the community sample (odds ratio [OR] 5.28, confidence interval [CI] 95% 3.07-9.08; P-value <0.001). There was no effect of gender. Subgroup analyses showed no significant association of MS with clozapine/olanzapine use, treatment duration or tobacco use. There was an association between treatment duration and hypertriglyceridemia (P = 0.024; OR 1.02, CI 95% 1.00-1.04) and obesity (P = 0.007; OR 5.93, CI 95% 1.82-20.22). Clozapine/olanzapine use was associated with hyperglycaemia (P = 0.007; OR 6.04, CI 95% 1.63-22.38) and high low density lipoprotein (P = 0.033 ANOVA; OR 5.28, CI 95% 1.14-24.37).

CONCLUSION

Latino psychotic patients have a high risk of MA and MS at initial stages of the disease which is not entirely explained by the higher risk in the whole Latino population, is irrespective of gender, and does not seem to be entirely a response to atypical antipsychotic use.

Health state utility values in schizophrenia: protocol for a systematic review and meta-analysis

INTRODUCTION

Cost-effectiveness analyses that use quality-adjusted life-years (QALYs) allow comparing the value for money of interventions across different health problems. Health state utility values (HSUVs) are crucial to calculate QALYs. These are weights attached to a given health state reflecting preferences in health-related quality of life (HRQoL). In schizophrenia, there is extensive evidence about the consequences of this condition on HRQoL. Besides, several interventions have claimed to be cost-effective in terms of QALYs gained. Despite this evidence, a systematic review of HSUVs has not been conducted. Therefore, we aim to synthesise the evidence about HSUVs in schizophrenia.

METHODS AND ANALYSIS

We will conduct a systematic review of the literature about HSUVs in people with schizophrenia following the Preferred Reporting Items for Systematic review and Meta-Analysis and the International Society for Pharmacoeconomics and Outcomes Research task force recommendations. The submissions records of eight electronic peer-reviewed databases and three health technology assessment (HTA) agencies will be searched. Quantitative synthesis will be carried out in comparable studies, using random-effects meta-analysis. Heterogeneity will be explored using meta-regression if more than 10 studies per covariate are found. A narrative synthesis and methodological quality of included studies will be also reported.

DISCUSSION

This review will provide a synthesis of the HSUVs estimated for different states experienced by people with schizophrenia. This will inform analysts when calculating QALYs, using values in a more transparent and accountable manner. Finally, it will shed light on evidence gaps and limitations about this measure in mental health.

PROSPERO REGISTRATION NUMBER

CRD42019123582.

Early treatment resistance in a Latin-American cohort of patients with schizophrenia

BACKGROUND

Failure to respond to antipsychotic medication in schizophrenia is a common clinical scenario with significant morbidity. Recent studies have highlighted that many patients present treatment-resistance from disease onset. We here present an analysis of clozapine prescription patterns, used as a real-world proxy marker for treatment-resistance, in a cohort of 1195 patients with schizophrenia from a Latin-American cohort, to explore the timing of emergence of treatment resistance and possible subgroup differences.

METHODS

Survival analysis from national databases of clozapine monitoring system, national disease notification registers, and discharges from an early intervention ward.

RESULTS

Echoing previous studies, we found that around 1 in 5 patients diagnosed with schizophrenia were eventually prescribed clozapine, with an over-representation of males and those with a younger onset of psychosis. The annual probability of being prescribed clozapine was highest within the first year (probability of 0.11, 95% confidence interval of 0.093-0.13), compared to 0.018 (0.012-0.024) between years 1 and 5, and 0.006 (0-0.019) after 5years. Age at psychosis onset, gender, dose of clozapine used, and compliance with hematological monitoring at 12months, was not related to the onset of treatment resistance. A similar pattern was observed in a subgroup of 230 patients discharged from an early intervention ward with a diagnosis of non-affective first episode of psychosis.

CONCLUSIONS

Our results highlight that treatment resistance is frequently present from the onset of psychosis. Future studies will shed light on the possible different clinical and neurobiological characteristics of this subtype of psychosis.