Development of novel imaging techniques to study the brain in severe mental health disorders

Project Title

Partner Organisations

Facultad de Medicina Clínica Alemana Universidad del Desarrollo

Internal ID

ACT192064

Principal Investigator

Cristian Tejos (PUC)

Start Date

2019

Publications

Now showing 1 - 10 of 23

Some of the metrics are blocked by your
consent settings
Dysconnectivity in Schizophrenia Revisited: Abnormal Temporal Organization of Dynamic Functional Connectivity in Patients With a First Episode of Psychosis
(2022)
Juan P Ramirez-Mahaluf
;
Ángeles Tepper
;
Luz Maria Alliende
;
Carlos Mena
;
Carmen Paz Castañeda
<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background and Hypothesis</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Study Design</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Study Results</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>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.</jats:p> </jats:sec>
Scopus© Citations 17 1
Some of the metrics are blocked by your
consent settings
Functional Dysconnectivity in Ventral Striatocortical Systems in 22q11.2 Deletion Syndrome
(2021)
Ángeles Tepper
;
Analía Cuiza
;
Luz María Alliende
;
Carlos Mena
;
Juan Pablo Ramirez-Mahaluf
<jats:title>Abstract</jats:title> <jats:p>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.</jats:p>
1Scopus© Citations 6
Some of the metrics are blocked by your
consent settings
Differences of affective and non-affective psychoses in early intervention services from Latin America
(2022)
Raphael O. Cerqueira
;
Carolina Ziebold
;
Daniel Cavalcante
;
Giovany Oliveira
;
Javiera Vásquez
Scopus© Citations 8 8
Some of the metrics are blocked by your
consent settings
Effects of socioeconomic status in cognition of people with schizophrenia: results from a Latin American collaboration network with 1175 subjects
(2021)
Letícia Sanguinetti Czepielewski
;
Luz Maria Alliende
;
Carmen Paz Castañeda
;
Mariana Castro
;
Salvador M. Guinjoan
<jats:title>Abstract</jats:title><jats:sec id="S0033291721002403_sec_a1"><jats:title>Background</jats:title><jats:p>Cognition heavily relies on social determinants and genetic background. Latin America comprises approximately 8% of the global population and faces unique challenges, many derived from specific demographic and socioeconomic variables, such as violence and inequality. While such factors have been described to influence mental health outcomes, no large-scale studies with Latin American population have been carried out. Therefore, we aim to describe the cognitive performance of a representative sample of Latin American individuals with schizophrenia and its relationship to clinical factors. Additionally, we aim to investigate how socioeconomic status (SES) relates to cognitive performance in patients and controls.</jats:p></jats:sec><jats:sec id="S0033291721002403_sec_a2" sec-type="methods"><jats:title>Methods</jats:title><jats:p>We included 1175 participants from five Latin American countries (Argentina, Brazil, Chile, Colombia, and Mexico): 864 individuals with schizophrenia and 311 unaffected subjects. All participants were part of projects that included cognitive evaluation with MATRICS Consensus Cognitive Battery and clinical assessments.</jats:p></jats:sec><jats:sec id="S0033291721002403_sec_a3" sec-type="results"><jats:title>Results</jats:title><jats:p>Patients showed worse cognitive performance than controls across all domains. Age and diagnosis were independent predictors, indicating similar trajectories of cognitive aging for both patients and controls. The SES factors of education, parental education, and income were more related to cognition in patients than in controls. Cognition was also influenced by symptomatology.</jats:p></jats:sec><jats:sec id="S0033291721002403_sec_a4" sec-type="conclusions"><jats:title>Conclusions</jats:title><jats:p>Patients did not show evidence of accelerated cognitive aging; however, they were most impacted by a lower SES suggestive of deprived environment than controls. These findings highlight the vulnerability of cognitive capacity in individuals with psychosis in face of demographic and socioeconomic factors in low- and middle-income countries.</jats:p></jats:sec>
4Scopus© Citations 28
Some of the metrics are blocked by your
consent settings
Mapping Subcortical Brain Alterations in 22q11.2 Deletion Syndrome: Effects of Deletion Size and Convergence With Idiopathic Neuropsychiatric Illness
(2020)
Christopher R.K. Ching
;
Boris A. Gutman
;
Daqiang Sun
;
Julio Villalon Reina
;
Anjanibhargavi Ragothaman
Scopus© Citations 44 8
Some of the metrics are blocked by your
consent settings
Pharmacogenetics in Psychiatry: Perceived Value and Opinions in a Chilean Sample of Practitioners
(2021)
UNDURRAGA FOURCADE, JUAN PABLO
;
Ignacio Bórquez-Infante
;
Nicolás A. Crossley
;
Miguel L. Prieto
;
REPETTO LISBOA, MARIA GABRIELA
<jats:p>Use of pharmacogenetics (PGx) testing to guide clinical decisions is growing in developed countries. Published guidelines for gene–drug pair analysis are available for prescriptions in psychiatry, but information on their utilization, barriers, and health outcomes in Latin America is limited. As a result, this work aimed at exploring current use, opinions, and perceived obstacles on PGx testing among psychiatrists in Chile, via an online, anonymous survey. Among 123 respondents (5.9% of registered psychiatrists in the country), 16.3% reported ever requesting a PGx test. The vast majority (95%) of tests were ordered by clinicians practicing in the Metropolitan Region of Santiago. Having more than 20 years in practice was positively associated with prior use of PGx (p 0.02, OR 3.74 (1.19–11.80)), while working in the public health system was negatively associated (OR 0.30 (0.10–0.83)). Perceived barriers to local implementation included insufficient evidence of clinical utility, limited clinicians’ knowledge on PGx and on test availability, and health systems’ issues, such as costs and reimbursement. Despite the recognition of these barriers, 80% of respondents asserted that it is likely that they will incorporate PGx tests in their practice in the next five years. Given these results, we propose next steps to facilitate implementation such as further research in health outcomes and clinical utility of known and novel clinically actionable variants, growth in local sequencing capabilities, education of clinicians, incorporation of clinical decision support tools, and economic evaluations, all in local context.</jats:p>
1Scopus© Citations 10
Some of the metrics are blocked by your
consent settings
Structural brain abnormalities in schizophrenia in adverse environments: examining the effect of poverty and violence in six Latin American cities
(2020)
Nicolas A. Crossley
;
Andre Zugman
;
Francisco Reyes-Madrigal
;
Leticia S. Czepielewski
;
Mariana N. Castro
<jats:title>Summary</jats:title><jats:sec id="S0007125020001439_sec_a1"><jats:title>Background</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec id="S0007125020001439_sec_a2"><jats:title>Aims</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec id="S0007125020001439_sec_a3" sec-type="methods"><jats:title>Method</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec id="S0007125020001439_sec_a4" sec-type="results"><jats:title>Results</jats:title><jats:p>A total of 334 patients with schizophrenia and 262 controls were included. Income was differentially related to total grey matter volume in both groups (<jats:italic>P</jats:italic> = 0.006). Controls showed a positive correlation between total grey matter volume and income (<jats:italic>R</jats:italic> = 0.14, <jats:italic>P</jats:italic> = 0.02). Surprisingly, this relationship was not present in patients with schizophrenia (<jats:italic>R</jats:italic> = −0.076, <jats:italic>P</jats:italic> = 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.</jats:p></jats:sec><jats:sec id="S0007125020001439_sec_a5" sec-type="conclusions"><jats:title>Conclusions</jats:title><jats:p>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.</jats:p></jats:sec>
Scopus© Citations 10 1
Some of the metrics are blocked by your
consent settings
Emotional intelligence: a comparison between patients after first episode mania and those suffering from chronic bipolar disorder type I
(2022)
Cristina Varo
;
Silvia Amoretti
;
Giulio Sparacino
;
Esther Jiménez
;
Brisa Solé
<jats:title>Abstract</jats:title> <jats:sec id="S0033291721005122_sec_a1"> <jats:title>Background</jats:title> <jats:p>Deficits in emotional intelligence (EI) were detected in patients with bipolar disorder (BD), but little is known about whether these deficits are already present in patients after presenting a first episode mania (FEM). We sought (i) to compare EI in patients after a FEM, chronic BD and healthy controls (HC); (ii) to examine the effect exerted on EI by socio-demographic, clinical and neurocognitive variables in FEM patients.</jats:p> </jats:sec> <jats:sec id="S0033291721005122_sec_a2" sec-type="methods"> <jats:title>Methods</jats:title> <jats:p>The Emotional Intelligence Quotient (EIQ) was calculated with the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). Performance on MSCEIT was compared among the three groups using generalized linear models. In patients after a FEM, the influence of socio-demographic, clinical and neurocognitive variables on the EIQ was examined using a linear regression model.</jats:p> </jats:sec> <jats:sec id="S0033291721005122_sec_a3" sec-type="results"> <jats:title>Results</jats:title> <jats:p>In total, 184 subjects were included (FEM <jats:italic>n</jats:italic> = 48, euthymic chronic BD type I <jats:italic>n</jats:italic> = 75, HC <jats:italic>n</jats:italic> = 61). BD patients performed significantly worse than HC on the EIQ [mean difference (MD) = 10.09, standard error (<jats:sc>s.e.)</jats:sc> = 3.14, <jats:italic>p</jats:italic> = 0.004] and on the understanding emotions branch (MD = 7.46, <jats:sc>s.e.</jats:sc> = 2.53, <jats:italic>p</jats:italic> = 0.010). FEM patients did not differ from HC and BD on other measures of MSCEIT. In patients after a FEM, EIQ was positively associated with female sex (<jats:italic>β</jats:italic> = −0.293, <jats:italic>p</jats:italic> = 0.034) and verbal memory performance (<jats:italic>β</jats:italic> = 0.374, <jats:italic>p</jats:italic> = 0.008). FEM patients performed worse than HC but better than BD on few neurocognitive domains.</jats:p> </jats:sec> <jats:sec id="S0033291721005122_sec_a4" sec-type="conclusions"> <jats:title>Conclusions</jats:title> <jats:p>Patients after a FEM showed preserved EI, while patients in later stages of BD presented lower EIQ, suggesting that impairments in EI might result from the burden of disease and neurocognitive decline, associated with the chronicity of the illness.</jats:p> </jats:sec>
Scopus© Citations 4 2
Some of the metrics are blocked by your
consent settings
Prodromal phase: Differences in prodromal symptoms, risk factors and markers of vulnerability in first episode mania versus first episode psychosis with onset in late adolescence or adulthood
(2022)
Norma Verdolini
;
Roger Borràs
;
Giulio Sparacino
;
Marina Garriga
;
Maria Sagué‐Vilavella
Scopus© Citations 9 2
Some of the metrics are blocked by your
consent settings
Abnormal nodal and global network organization in resting state functional MRI from subjects with the 22q11 deletion syndrome
(2021)
Teuntje A. D. Pelgrim
;
Matthijs G. Bossong
;
Analía Cuiza
;
Luz María Alliende
;
Carlos Mena
<jats:title>Abstract</jats:title><jats:p>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.</jats:p>
Scopus© Citations 2 1

Filters

Settings

Sort By

Results per page