Intra and inter-individual variability in functional connectomes of patients with First Episode of Psychosis

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

Intra and Inter-Individual Variability in Functional Connectomes of Patients with First Episode of Psychosis

Test-retest functional connectomes for 32 Healthy Controls and 30 First Episode of Psychosis patients. This dataset was originally used in the following article: (Preprint) Tepper, Ángeles and Núñez, Javiera Vásquez and Ramirez-Mahaluf, Juan Pablo and Aguirre, Juan Manuel and Barbagelata, Daniella and Maldonado, Elisa and Dellarossa, Camila Díaz and Nachar, Ruben and Gonzalez-Valderrama, Alfonso and Undurraga, Juan and Goñi, Joaquín and Crossley, Nicolas, Intra and Inter-Individual Variability in Functional Connectomes of Patients with First Episode of Psychosis. Available at SSRN: https://ssrn.com/abstract=4241607 or http://dx.doi.org/10.2139/ssrn.4241607 More details and python code used for analyses can be found in this GitHub repositoryThis work was supported by the Agencia Nacional de Investigación y Desarrollo from Chile (ANID), through its grants ANILLO PIA ACT192064 and ACT1414, FONDECYT regular 1200601, doctoral fellowship 21190222, and the Millenium Science Initiative Program – ICN2021_004

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

Summary 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- A nd middle-income countries, where potentially less brain vulnerability (less grey matter loss) is sufficient to become unwell in adverse (poor) environments.Fil: Crossley, Nicolas A.. Pontificia Universidad Católica de Chile; ChileFil: Zugman, Andre. Universidade Federal de Sao Paulo; BrasilFil: Reyes Madrigal, Francisco. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Czepielewski, Leticia S.. Universidade Federal do Rio Grande do Sul; BrasilFil: Castro, Mariana Nair. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Salud Mental; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Diaz Zuluaga, Ana M.. Universidad de Antioquia; ColombiaFil: Pineda Zapata, Julian A.. No especifíca;Fil: Reckziegel, Ramiro. Universidade Federal do Rio Grande do Sul; BrasilFil: Gadelha, Ary. Universidade Federal de Sao Paulo; BrasilFil: Jackowski, Andrea. Universidade Federal de Sao Paulo; BrasilFil: Noto, Cristiano. Universidade Federal de Sao Paulo; BrasilFil: Alliende, Luz M.. Pontificia Universidad Católica de Chile; ChileFil: Iruretagoyena, Barbara. Pontificia Universidad Católica de Chile; ChileFil: Ossandon, Tomas. Pontificia Universidad Católica de Chile; ChileFil: Ramirez Mahaluf, Juan P.. Pontificia Universidad Católica de Chile; ChileFil: Castañeda, Carmen P.. Instituto Psiquiátrico Dr. José Horwitz Barak; ChileFil: Gonzalez Valderrama, Alfonso. Universidad Finis Terrae; ChileFil: Nachar, Ruben. Instituto Psiquiátrico Dr. José Horwitz Barak; ChileFil: León Ortiz, Pablo. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Undurraga, Juan. Universidad del Desarrollo; ChileFil: López Jaramillo, Carlos. Universidad de Antioquia; ColombiaFil: Guinjoan, Salvador Martín. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Salud Mental; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Gama, Clarissa S.. Universidade Federal do Rio Grande do Sul; BrasilFil: De La Fuente Sandoval, Camilo. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Bressan, Rodrigo A.. Universidade Federal de Sao Paulo; Brasi