title: Abnormal white matter integrity in antipsychotic-naïve first-episode psychosis patients assessed by a DTI principal component analysis.
abstract: BACKGROUND
  Diffusion tensor imaging (DTI) studies in patients with schizophrenia have shown abnormalities in the microstructure of white matter tracts. Specifically, reduced fractional anisotropy (FA) has been described across multiple white matter tracts, in studies that have mainly included patients treated with antipsychotic medications.
  
  
  OBJECTIVE
  To compare FA in antipsychotic-naïve patients experiencing a first episode of psychosis (FEP) to FA in healthy controls to demonstrate that the variance of FA can be grouped, in a coincidental manner, in four predetermined factors in accordance with a theoretical partition of the white matter tracts, using a principal components analysis (PCA).
  
  
  METHODS
  Thirty-five antipsychotic-naïve FEP patients and 35 age- and gender-matched healthy controls underwent DTI at 3T. Analysis was performed using a tract-based spatial statistics (TBSS) method and exploratory PCA.
  
  
  RESULTS
  DTI analysis showed extensive FA reduction in white matter tracts in FEP patients compared with the control group. The PCA grouped the white matter tracts into four factors explaining 66% of the total variance. Comparison of the FA values within each factor highlighted the differences between FEP patients and controls.
  
  
  CONCLUSIONS
  Our study confirms extensive white matter tracts anomalies in patients with schizophrenia, more specifically, in drug-naïve FEP patients. The results also indicate that a small number of white matter tracts share common FA anomalies that relate to deficit symptoms in FEP patients. Our study adds to a growing body of literature emphasizing the need for treatments targeting white matter function and structure in FEP patients.
authors.affiliation: Laboratory of Experimental Psychiatry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: Alvarado-Alanis
authors.affiliation: Laboratory of Experimental Psychiatry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico; Department of Education, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico.
authors.forename: Pablo
authors.initials: P
authors.lastname: León-Ortiz
authors.affiliation: Laboratory of Experimental Psychiatry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Reyes-Madrigal
authors.affiliation: MR Advanced Applications, GE Healthcare, Mexico City, Mexico.
authors.forename: Rafael
authors.initials: R
authors.lastname: Favila
authors.affiliation: Early Psychosis Intervention Department, Hospital Fray Bernardino Álvarez, Mexico City, Mexico; Palliative Care Unit, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Oscar
authors.initials: O
authors.lastname: Rodríguez-Mayoral
authors.affiliation: Instituto Nacional de Medicina Genómica, Mexico City, Mexico.
authors.forename: Humberto
authors.initials: H
authors.lastname: Nicolini
authors.affiliation: Neuropsychiatry Department, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico.
authors.forename: Mariana
authors.initials: M
authors.lastname: Azcárraga
authors.affiliation: Multimodal Neuroimaging Schizophrenia Group, Research Imaging Centre and Geriatric Mental Health Program, Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, Canada.
authors.forename: Ariel
authors.initials: A
authors.lastname: Graff-Guerrero
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, USA; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, USA.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Rowland
authors.affiliation: Laboratory of Experimental Psychiatry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico; Neuropsychiatry Department, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico. Electronic address: fcamilo@unam.mx.
authors.forename: Camilo
authors.initials: C
authors.lastname: de la Fuente-Sandoval
mesh_terms: D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D025341:Principal Component Analysis; D012559:Schizophrenia / Q000473:pathology*; D066127:White Matter / Q000473:pathology*; D055815:Young Adult
keywords: Diffusion tensor imaging; First-episode psychosis; Fractional anisotropy; Principal component analysis; Schizophrenia; TBSS