Browsing by Author "Zugman, Andre"

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    Imaging social and environmental factors as modulators of brain dysfunction: time to focus on developing, non-Western societies
    (2019) Crossley Karmelic, Nicolas Andres; Alliende Serra, Luz Maria; Ossandón Valdés, Tomás; Castañeda, Carmen Paz; González-Valderrama, Alfonso; Undurraga, Juan; Castro, Mariana; Guinjoan, Salvador; Diaz-Zuluanga, Ana María; Pineda Zapata, Julian A.; Lopez-Jaramillo, Carlos; Reyes-Madrigal, Francisco; De la fuente Sandoval, Camilo; León-Ortíz, Pablo; Sanguinetti Czepielewski, Leticia; Gama, Clarissa S.; Zugman, Andre; Gadelha, Ary; Jackowski, Andrea; Bressan, Rodrigo
    Social and environmental factors are known risk factors and modulators of mental health disorders. We here conducted a nonsystematic review of the neuroimaging literature studying the effects of poverty, urbanicity, and community violence, highlighting the opportunities of studying non-Western developing societies such as those in Latin America. Social and environmental factors in these communities are widespread and have a large magnitude, as well as an unequal distribution, providing a good opportunity for their characterization. Studying the effect of poverty in these settings could help to explore the brain effect of economic improvements, disentangle the effect of absolute and relative poverty, and characterize the modulating impact of poverty on the underlying biology of mental health disorders. Exploring urbanicity effects in highly unequal cities could help identify the specific factors that modulate this effect as well as examine a possible dose-response effect by studying megacities. Studying brain changes in those living among violence, which is particularly high in places such as Latin America, could help to characterize the interplay between brain predisposition and exposure to violence. Furthermore, exploring the brain in an adverse environment should shed light on the mechanisms underlying resilience. We finally provide examples of two methodological approaches that could contribute to this field, namely a big cohort study in the developing world and a consortium-based meta-analytic approach, and argue about the potential translational value of this research on the development of effective social policies and successful personalized medicine in disadvantaged societies.
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    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.