title: Gray matter, white matter, brain, and intracranial volumes in first-episode bipolar disorder: a meta-analysis of magnetic resonance imaging studies.
abstract: OBJECTIVE
  To perform a comprehensive quantitative analysis of the existing magnetic resonance imaging (MRI) studies of the brain conducted on patients with first-episode bipolar disorder (BD).
  
  
  METHODS
  A systematic search was performed of MRI studies that reported quantitative measurements of brain volumes of first-episode bipolar patients and healthy controls. Four meta-analyses were performed for four cerebral regions.
  
  
  RESULTS
  Significant overall effect sizes were demonstrated, with a reduction detected in patients with BD for total intracranial and white matter volumes, but not for gray matter and whole brain volumes.
  
  
  CONCLUSIONS
  The available MRI literature indicates that specific structural brain abnormalities are already present in first-episode bipolar patients. These do not overlap with those emerging from previous meta-analyses performed in patients with chronic BD. These findings support the hypothesis of different patterns of changes in brain morphology over the time course of bipolar disorder.
authors.affiliation: University of Brescia I, School of Medicine, Brescia, Italy. vita@med.unibs.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Vita
authors.forename: Luca
authors.initials: L
authors.lastname: De Peri
authors.forename: Emilio
authors.initials: E
authors.lastname: Sacchetti
mesh_terms: D001714:Bipolar Disorder / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male