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Browsing by Author "Undurraga, Juan"

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Childhood adversity increases risk of psychotic experiences in patients with substance use disorder
(ELSEVIER IRELAND LTD, 2022) Borquez-Infante, Ignacio; Vasquez, Javiera; Dupre, Sofia; Undurraga, Eduardo A.; Crossley, Nicolas A.; Undurraga, Juan
Introduction: Adverse childhood experiences (ACEs) increase the risk of psychotic experiences (PE), but little is known about heterogeneities of this association in different developmental stages, dimensions, or whether they are affected by substance use disorder (SUD). This study examines the association between different types of ACEs at various developmental stages and lifetime PE in patients with SUD in Chile.Methods: We included 399 consenting adults in outpatient or residential SUD treatment programs. Sociodemo-graphic data and information about PE and ACEs were obtained by trained clinical psychologists.Results: Patients reporting PE experienced more ACEs compared to patients without PE (4.2 versus 3.4). They also experienced more complex adversities (41.8% versus 25.1%), had more psychiatric comorbidities (85% versus 70.4%), and reported using more substances (mean 4.5 versus 3.9). Adjusted association between ACEs and PE showed the highest OR for arrests (1.88), sexual abuse (1.81), alcohol abuse by parents (1.48), school exclusion (1.39), foster or residential care (18.3).Conclusion: Early exposure to ACEs is a risk factor for later PE among patients with SUD. Type of ACE and the period when they occurred is important, suggesting the existence of critical periods where the individual is more susceptible to adverse environmental stimuli.
Clinical characterization of rapid cycling bipolar disorder: Association with attention deficit hyperactivity disorder
(2018) Aedo, Alberto; Murru, Andrea; Sánchez Anabalón, Raúl Francisco; Grande, Iria; Vieta, Eduard; Undurraga, Juan
Country-level gender inequality is associated with structural differences in the brains of women and men
(National Academy of Sciences, 2023) Zugman, Andrés; Alliende, Luz María; Medel Sierralta, Vicente Nicolás; Bethlehem, Richard A. I.; Seidlitz, Jakob; Ringlein, Grace; Arango, Celso; Arnatkeviciutė, Aurina; Asmal, Laila; Bellgrove, Mark; Benegal, Vivek; Bernardo, Miquel; Billeke, Pablo; Bosch-Bayard, Jorge; Bressan, Rodrigo; Busatto, Geraldo F.; Castro, Mariana N.; Chaim-Avancini, Tiffany; Compte, Albert; Costanzi, Monise; Czepielewski, Leticia; Dazzan, Paola; Fuente-Sandoval, Camilo de la; Forti, Marta di; Díaz-Caneja, Covadonga M.; Díaz-Zuluaga, Ana María; Plessis, Stefan du; Duran, Fabio L. S.; Fittipaldi, Sol; Fornito, Alex; Freimer, Nelson B.; Gadelha, Ary; Gama, Clarissa S.; Garani, Ranjini; García-Rizo, Clemente; González Campo, Cecilia; González-Valderrama, Alfonso; Guinjoan, Salvador; Holla, Bharath; Ibáñez, Agustín; Jackowski, Andrea; Ivanovic, Daniza; León-Ortiz, Pablo; Lochner, Christine; López Jaramillo, Carlos; Luckhoff, Hilmar; Massuda, Raffael; McGuire, Philip; Miyata, Jun; Mizrahi, Romina; Murray, Robin; Ozerdem, Aysegul; Pan, Pedro M.; Parellada, Mara; Phahladira, Lebogan; Ramírez Mahaluf, Juan P.; Reckziegel, Ramiro; Marques Tiago Reis; Reyes-Madrigal, Francisco; Roos, Annerine; Rosa, Pedro; Salum, Giovanni; Scheffler, Freda; Schumann, Gunter; Serpa, Mauricio; Stein, Dan J.; Tepper, Angeles; Tiego, Jeggan; Ueno, Tsukasa; Undurraga, Juan; Undurraga, Eduardo A.; Valdés-Sosa, Pedro; Valli, Isabel; Villarreal, Mirta; Winton-Brown, Toby T.; Yalin, Nefize; Zamorano, Francisco; Zanetti, Marcus V.; Veda, C.; Winkler, Anderson M.; Pine, Daniel S.; Evans-Lacko, Sara; Crossley Karmelic, Nicolas Andrés
Gender inequality across the world has been associated with a higher risk to mental health problems and lower academic achievement in women compared to men. We also know that the brain is shaped by nurturing and adverse socio-environmental experiences. Therefore, unequal exposure to harsher conditions for women compared to men in gender-unequal countries might be reflected in differences in their brain structure, and this could be the neural mechanism partly explaining women’s worse outcomes in gender-unequal countries. We examined this through a random-effects meta-analysis on cortical thickness and surface area differences between adult healthy men and women, including a meta-regression in which country-level gender inequality acted as an explanatory variable for the observed differences. A total of 139 samples from 29 different countries, totaling 7,876 MRI scans, were included. Thickness of the right hemisphere, and particularly the right caudal anterior cingulate, right medial orbitofrontal, and left lateral occipital cortex, presented no differences or even thicker regional cortices in women compared to men in gender-equal countries, reversing to thinner cortices in countries with greater gender inequality. These results point to the potentially hazardous effect of gender inequality on women’s brains and provide initial evidence for neuroscience-informed policies for gender equality.
Depressive symptoms are associated with higher morning plasma cortisol in primary care subjects
(2018) Capponi, Valentina; Carrasco, Carmen; Macchiavello, Stefano; Undurraga, Juan; Campino Johnson, María del Carmen; Carvajal, Cristian; Gomez, Teresita; Weiss, Cristian; Aedo Campos, Igor Iván; Vecchiola Cárdenas, Andrea Paola; Allende, Fidel; Solari, Sandra; Fardella B., Carlos; Baudrand Biggs, René; Capponi, Valentina; Carrasco, Carmen; Macchiavello, Stefano; Undurraga, Juan; Campino Johnson, María del Carmen; Carvajal, Cristian; Gomez, Teresita; Weiss, Cristian; Aedo Campos, Igor Iván; Vecchiola, Andrea; Allende, Fidel; Solari, Sandra; Fardella B., Carlos; Baudrand Biggs, René
Differences of affective and non-affective psychoses in early intervention services from Latin America
(2022) Cerqueira, Raphael O.; Ziebold, Carolina; Cavalcante, Daniel; Oliveira, Giovany; Vasquez Nuñez, Javiera Eugenia; Undurraga, Juan; Gonzalez-Valderrama, Alfonso; Nachar, Ruben; Lopez-Jaramillo, Carlos; Noto, Cristiano; Crossley Karmelic, Nicolas Andres; Gadelha, Ary
Background: Psychosis presentation can be affected by genetic and environmental factors. Differentiating be-tween affective and non-affective psychosis (A-FEP and NA-FEP, respectively) may influence treatment decisions and clinical outcomes. The objective of this paper is to examine differences between patients with A-FEP or NA-FEP in a Latin American sample.Methods: Patients from two cohorts of patients with a FEP recruited from Brazil and Chile. Subjects included were aged between 15 and 30 years, with an A-FEP or NA-FEP (schizophrenia-spectrum disorders) according to DSM-IV-TR. Sociodemographic data, duration of untreated psychosis and psychotic/mood symptoms were assessed. Generalized estimating equation models were used to assess clinical changes between baseline-follow-up ac-cording to diagnosis status.Results: A total of 265 subjects were included. Most of the subjects were male (70.9 %), mean age was 21.36 years. A-FEP and NA-FEP groups were similar in almost all sociodemographic variables, but A-FEP patients had a higher probability of being female. At baseline, the A-FEP group had more manic symptoms and a steeper reduction in manic symptoms scores during the follow-up. The NA-FEP group had more negative symptoms at baseline and a higher improvement during follow-up. All domains of The Positive and Negative Syndrome Scale improved for both groups. No difference for DUP and depression z-scores at baseline and follow-up. Limitations: The sample was recruited at tertiary hospitals, which may bias the sample towards more severe cases.Conclusions: This is the largest cohort comparing A-FEP and NA-FEP in Latin America. We found that features in FEP patients could be used to improve diagnosis and support treatment decisions.
Dysconnectivity in Schizophrenia Revisited: Abnormal Temporal Organization of Dynamic Functional Connectivity in Patients With a First Episode of Psychosis
(2023) Ramirez-Mahaluf, Juan P.; Tepper, Angeles; Maria Alliende, Luz; Mena, Carlos; Castaneda, Carmen Paz; Iruretagoyena, Barbara; Nachar, Ruben; Reyes-Madrigal, Francisco; Leon-Ortiz, Pablo; Mora-Duran, Ricardo; Ossandon, Tomas; Gonzalez-Valderrama, Alfonso; Undurraga, Juan; De la Fuente-Sandoval, Camilo; Crossley, Nicolas A.
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-naive 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-naive 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.
Early treatment resistance in a Latin-American cohort of patients with schizophrenia
(2018) Mena, Cristián; González Valderrama, Alfonso; Iruretagoyena, Bárbara; Undurraga, Juan; Crossley, Nicolás
Effects of socioeconomic status in cognition of people with schizophrenia: Results from a Latin American collaboration network with 1175 subjects
(2021) Sanguinetti Czepielewski, Letícia; Alliende Serra, Luz María; Castañeda, Carmen Paz; Castro, Mariana; Guinjoan, Salvador M.; Massuda, Raffael; Berberian, Arthur A.; Fonseca, Ana Olivia; González-Valderrama A.; Gadelha, Ary; Bressan, Rodrigo; Crivelaro, Marisa; Louzã, Mario; Undurraga, Juan; González-Valderrama, Alfonso; López-Jaramillo, Carlos; Nieto, Rodrigo R.; Montes, Cristián; Silva, Henán; Langer, Álvaro I.; Valencia-Echeverry, Johanna; López-Jaramillo, Carlos; Solís-Vivanco, Rodolfo; Reyes-Madrigal, Francisco; Fuente-Sandoval, Camilo de la; Crossley, Nicolás A.; Gama, Clarissa S.
Background 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. Methods 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. Results 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. Conclusions 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.
Functional Dysconnectivity in Ventral Striatocortical Systems in 22q11.2 Deletion Syndrome
(OXFORD UNIV PRESS, 2021) Tepper, Angeles; Cuiza Vasquez Analia; Alliende, Luz María; Mena, Carlos; Ramirez Mahaluf, Juan Pablo; Iruretagoyena, Barbara; Ornstein, Claudia; Fritsch, Rosemarie; Nachar, Ruben; Gonzalez Valderrama, Alfonso; Undurraga, Juan; Pablo Cruz, Juan; Tejos, Cristian; Fornito, Alex; Repetto, Gabriela; Crossley, Nicolas
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 x 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.
Gender, age and geographical representation over the past 50 years of schizophrenia research
(2022) Alliende, Luz MarÍa; Czepielewski, Leticia S.; Aceituno Farías, David; Paz Castaneda, Carmen; Díaz, Camila; Iruretagoyena Bruce, Bárbara Arantzazu; Mena, Carlos; Mena, Cristian; Ramírez Mahaluf, Juan Pablo; Tepper, Ángeles; Vásquez, Javiera; Fonseca, Lais; Machado, Viviane; Hernández, Camilo E.; Vargas Upegui, Cristian; Gómez Cruz, Gladys; Kobayashi Romero, Luis F.; Moncada Habib, Tomas; Evans Lacko, Sara; Bressan, Rodrigo; Gama, Clarissa S.; López Jaramillo, Carlos; de la Fuente Sandoval, Camilo; González Valderrama, Alfonso; Undurraga, Juan; Gadelha, Ary; Crossley Karmelic, Nicolás Andrés; ANDES Network
Previous studies have suggested that subjects participating in schizophrenia research are not representative of the demographics of the global population of people with schizophrenia, particularly in terms of gender and geographical location. We here explored if this has evolved throughout the decades, examining changes in geographical location, gender and age of participants in studies of schizophrenia published in the last 50 years. We examined this using a meta-analytical approach on an existing database including over 3,000 studies collated for another project. We found that the proportion of studies and participants from low-and-middle income countries has significantly increased over time, with considerable input from studies from China. However, it is still low when compared to the global population they represent. Women have been historically underrepresented in studies, and still are in high-income countries. However, a significantly higher proportion of female participants have been included in studies over time. The age of participants included has not changed significantly over time. Overall, there have been improvements in the geographical and gender representation of people with schizophrenia. However, there is still a long way to go so research can be representative of the global population of people with schizophrenia, particularly in geographical terms.
Intra and inter-individual variability in functional connectomes of patients with First Episode of Psychosis
(Elsevier Inc., 2023) Tepper, Ángeles; Vásquez Núñez, Javiera; Ramirez-Mahaluf, Juan Pablo; Aguirre, Juan Manuel; Barbagelata, Daniella; Maldonado, Elisa; Díaz Dellarossa, Camila; Nachar, Ruben; González-Valderrama, Alfonso; Undurraga, Juan; Goñi, Joaquín; Crossley, Nicolás
© 2023 The Author(s)Patients with Schizophrenia may show different clinical presentations, not only regarding inter-individual comparisons but also in one specific subject over time. In fMRI studies, functional connectomes have been shown to carry valuable individual level information, which can be associated with cognitive and behavioral variables. Moreover, functional connectomes have been used to identify subjects within a group, as if they were fingerprints. For the particular case of Schizophrenia, it has been shown that there is reduced connectome stability as well as higher inter-individual variability. Here, we studied inter and intra-individual heterogeneity by exploring functional connectomes’ variability and related it with clinical variables (PANSS Total scores and antipsychotic's doses). Our sample consisted of 30 patients with First Episode of Psychosis and 32 Healthy Controls, with a test–retest approach of two resting-state fMRI scanning sessions. In our patients’ group, we found increased deviation from healthy functional connectomes and increased intragroup inter-subject variability, which was positively correlated to symptoms’ levels in six subnetworks (visual, somatomotor, dorsal attention, ventral attention, frontoparietal and DMN). Moreover, changes in symptom severity were positively related to changes in deviation from healthy functional connectomes. Regarding intra-subject variability, we were unable to replicate previous findings of reduced connectome stability (i.e., increased intra-subject variability), but we found a trend suggesting that result. Our findings highlight the relevance of variability characterization in Schizophrenia, and they can be related to evidence of Schizophrenia patients having a noisy functional connectome.
Obesity and brain structure in schizophrenia - ENIGMA study in 3021 individuals
(2022) McWhinney, Sean R.; Brosch, Katharina; Calhoun, Vince D.; Crespo-Facorro, Benedicto; Crossley, Nicolas A.; Dannlowski, Udo; Dickie, Erin; Dietze, Lorielle M. F.; Donohoe, Gary; Du Plessis, Stefan; Ehrlich, Stefan; Emsley, Robin; Furstova, Petra; Glahn, David C.; Gonzalez-Valderrama, Alfonso; Grotegerd, Dominik; Holleran, Laurena; Kircher, Tilo T. J.; Knytl, Pavel; Kolenic, Marian; Lencer, Rebekka; Nenadic, Igor; Opel, Nils; Pfarr, Julia-Katharina; Rodrigue, Amanda L.; Rootes-Murdy, Kelly; Ross, Alex J.; Sim, Kang; Skoch, Antonin; Spaniel, Filip; Stein, Frederike; Svancer, Patrik; Tordesillas-Gutierrez, Diana; Undurraga, Juan; Vaquez-Bourgon, Javier; Voineskos, Aristotle; Walton, Esther; Weickert, Thomas W.; Weickert, Cynthia Shannon; Thompson, Paul M.; van Erp, Theo G. M.; Turner, Jessica A.; Hajek, Tomas
Schizophrenia is frequently associated with obesity, which is linked with neurostructural alterations. Yet, we do not understand how the brain correlates of obesity map onto the brain changes in schizophrenia. We obtained MRI-derived brain cortical and subcortical measures and body mass index (BMI) from 1260 individuals with schizophrenia and 1761 controls from 12 independent research sites within the ENIGMA-Schizophrenia Working Group. We jointly modeled the statistical effects of schizophrenia and BMI using mixed effects. BMI was additively associated with structure of many of the same brain regions as schizophrenia, but the cortical and subcortical alterations in schizophrenia were more widespread and pronounced. Both BMI and schizophrenia were primarily associated with changes in cortical thickness, with fewer correlates in surface area. While, BMI was negatively associated with cortical thickness, the significant associations between BMI and surface area or subcortical volumes were positive. Lastly, the brain correlates of obesity were replicated among large studies and closely resembled neurostructural changes in major depressive disorders. We confirmed widespread associations between BMI and brain structure in individuals with schizophrenia. People with both obesity and schizophrenia showed more pronounced brain alterations than people with only one of these conditions. Obesity appears to be a relevant factor which could account for heterogeneity of brain imaging findings and for differences in brain imaging outcomes among people with schizophrenia.
Pharmacogenetics in Psychiatry: Perceived Value and Opinions in a Chilean Sample of Practitioners
(2021) Undurraga, Juan; Bórquez Infante, Ignacio; Crossley, Nicolás; Prieto, Miguel L.; Repetto, Gabriela M.
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.
Predictors of clozapine discontinuation at 2 years in treatment-resistant schizophrenia
(ELSEVIER, 2021) Iruretagoyena Bruce Barbara Arantzazu; Castañeda, Carmen Paz; Mena, Cristian; Diaz, Camila; Nachar, Ruben; Ramirez Mahaluf Juan Pablo; González Valderrama, Alfonso; Undurraga, Juan; Maccabe, James H; Crossley, Nicolas A
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
Quantitative Susceptibility Mapping MRI in Deep-Brain Nuclei in First-Episode Psychosis
(2023) García Saborit, Marisleydis; Jara Vallejos, Alejandro Antonio; Muñoz Camelo, Néstor Andrés; Milovic, Carlos; Tepper, Angeles; Alliende Correa, Luz María; Mena, Carlos; Iruretagoyena Bruce, Bárbara Arantzazu; Ramírez Mahaluf, Juan Pablo; Diaz, Camila; Nachar, Rubén; Castaneda, Carmen Paz; Gonzalez, Alfonso; Undurraga, Juan; Crossley, Nicolás; Tejos Núñez, Cristián Andrés
Background Psychosis is related to neurochemical changes in deep-brain nuclei, particularly suggesting dopamine dysfunctions. We used an magnetic resonance imaging-based technique called quantitative susceptibility mapping (QSM) to study these regions in psychosis. QSM quantifies magnetic susceptibility in the brain, which is associated with iron concentrations. Since iron is a cofactor in dopamine pathways and co-localizes with inhibitory neurons, differences in QSM could reflect changes in these processes. Methods We scanned 83 patients with first-episode psychosis and 64 healthy subjects. We reassessed 22 patients and 21 control subjects after 3 months. Mean susceptibility was measured in 6 deep-brain nuclei. Using linear mixed models, we analyzed the effect of case-control differences, region, age, gender, volume, framewise displacement (FD), treatment duration, dose, laterality, session, and psychotic symptoms on QSM. Results Patients showed a significant susceptibility reduction in the putamen and globus pallidus externa (GPe). Patients also showed a significant R2* reduction in GPe. Age, gender, FD, session, group, and region are significant predictor variables for QSM. Dose, treatment duration, and volume were not predictor variables of QSM. Conclusions Reduction in QSM and R2* suggests a decreased iron concentration in the GPe of patients. Susceptibility reduction in putamen cannot be associated with iron changes. Since changes observed in putamen and GPe were not associated with symptoms, dose, and treatment duration, we hypothesize that susceptibility may be a trait marker rather than a state marker, but this must be verified with long-term studies.
Structural brain abnormalities in schizophrenia in adverse environments: Examining the effect of poverty and violence in six Latin American cities
(2021) Crossley Karmelic, Nicolás Andrés; Zugman, Andre; Reyes-Madrigal, Francisco; Czepielewski, Leticia S.; Castro, Mariana N.; Díaz-Zuluaga, Ana M.; Pineda-Zapata, Julián A.; Reckziegel, Ramiro; Noto, Cristiano; Jackowski, Andrea; Alliende, Luz M.; Iruretagoyena, Bárbara; Ossandon, Tomás; Ramirez-Mahaluf, Juan P.; Castañeda, Carmen; González-Valderrama, Alfonso; Nachar, Rubén; León-Ortiz, Pablo; Undurraga, Juan; López-Jaramillo, Carlos; Guinjoan, Salvador; Gama, Clarissa; Fuente-Sandoval, Camilo de la; Bressan, Rodrigo
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 andcontrols fromsixLatinAmerican 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: Atotal 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 The risk of developing schizophrenia is modulated, among other factors, by the social and environmental context of where people live. Incidence rates of psychosis are different across countries,1 possibly reflecting variations in the environment. Proposed specific factors explaining this effect have included an urban upbringing,2 poverty3 and the neighbourhood crime rate.4 Where people live has also been related to recovery rates of schizophrenia, in the context of whether it is a low- or high-income country5 or experiencing periods of economic expansion or recession.6 Brain imaging studies have shown that many of these environmental factors are related to brain changes in healthy individuals. For example, young people raised in poverty in high-income countries show reductions in total brain grey matter.7 Exposure to childhood adversity and violence has also been related to differences in hippocampal and amygdala volumes.8 An unresolved question relates to how these environmental factors affect the biology of schizophrenia. Couldbraindifferences typically seen in patients with schizophrenia be accounted for by these environmental factors? How will the neuropathology of schizophrenia interact with brain changes related to the environment? Is there a double-hit situation, where * Joint last authors. 112 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.
Uso de cannabis en jóvenes hospitalizados por un primer episodio de psicosis: un estudio caso-control
(2020) Castañeda, Carmen Paz; Alliende Correa, Luz María; Iruretagoyena, Bárbara; Nachar, Rubén; Mancilla, Felipe; Diaz, Camila; Gallardo, Carlos; Mena, Cristian; Ramírez Mahaluf, Juan Pablo; Undurraga, Juan; González Valderrama, Alfonso; Crossley, Nicolás
Background: Cannabis use among young people in Chile has increased significantly in the last years. There is a consistent link between cannabis and psychosis. Aim: To compare cannabis use in patients with a first episode of psychosis and healthy controls. Material and Methods: We included 74 patients aged 20 +/- 3 years (78% males) admitted to hospital with a first episode of psychosis and a group of 60 healthy controls aged 23 +/- 4 years (63% males). Cannabis consumption was assessed, including age of first time use and length of regular use. Results: Patients with psychosis reported a non-significantly higher frequency of life-time cannabis use. Patients had longer periods of regular cannabis use compared with healthy subjects (Odds ratio [OR] 2.4; 95% confidence intervals [CI] 1.14-5.05). Patients also used cannabis for the first time at an earlier age (16 compared with 17 years, p < 0.0). The population attributable fraction for regular cannabis use associated with hospital admissions due to psychosis was 17.7% (95% CI 1.2-45.5%). Conclusions: Cannabis use is related to psychosis in this Chilean group of patients. This relationship is stronger in patients with early exposure to the drug and longer the regular use. One of every five admissions due to psychosis is associated with cannabis consumption. These data should influence cannabis legislation and the public policies currently being discussed in Chile.

Browsing by Author "Undurraga, Juan"

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