Country-level gender inequality is associated with structural differences in the brains of women and men

男女間の不平等と脳の性差 --男女間の不平等は脳構造の性差と関連する--. 京都大学プレスリリース. 2023-05-10.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

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

Gender, age and geographical representation over the past 50 years of schizophrenia research

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 under-represented 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

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

Background. Educational attainment is associated with well-being and health. Unfortunately, patients with schizophrenia achieve lower levels of education. Several effective interventions can ameliorate this. However, the magnitude of the education gap in schizophrenia and changes over time are unclear. Methods. We performed a systematic review and meta-analysis including all studies reporting on patients with schizophrenia and describing their years of education, with or without healthy controls. There were no other design constraints on studies. 22 reviewers participated in retrieving data from a search in PubMed and PsycINFO (January 1st, 1970, to November 24th, 2020). We estimated the birth date of participants from their mean age and publication date, and metaanalyzed these data, focusing on educational attainment, the education gap, and changes over time. The protocol was registered in PROSPERO (CRD42020220546). Outcomes. From 32,593 initial references, we included 3,321 studies reporting on 318,632 patients alongside 138,675 healthy controls (170,941 women and 275,821 men from studies describing gender; ethnicity was not collected). Patients educational attainment increased over time mirroring the controls.  However, patients achieved 19 months less than patients, and this remained unchanged throughout the decades. Studies were biased to include more educated patients and controls than their respective larger population, but results were unchanged in studies with groups with similar parental education. 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