Browsing by Author "Gonzalez-Valderrama, Alfonso"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- ItemDifferences 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, AryBackground: 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.
- ItemDysconnectivity 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.
- ItemObesity 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, TomasSchizophrenia 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.