title: Preliminary evidence for persistent abnormalities in amygdala volumes in adolescents and young adults with bipolar disorder.
abstract: OBJECTIVE
  Abnormalities in volumes of the amygdala have been reported previously in adolescents and adults with bipolar disorder (BD). Several studies have reported reduced volumes in adolescents with BD; however, both decreases and increases in volumes have been reported in adults with BD. Understanding of potential developmental contributions to these disturbances in morphology of the amygdala has been limited by the absence of longitudinal data in persons with BD. Here we use a within-subject longitudinal design to investigate whether amygdala volume abnormalities persist in adolescents and young adults with BD over a time interval of approximately 2 years.
  
  
  METHODS
  Participants included 18 adolescents and young adults: 10 participants with BD I and 8 healthy comparison participants. Amygdala volumes were measured on high-resolution magnetic resonance imaging scans acquired twice for each subject over intervals of approximately 2 years. Amygdala volumes were the dependent measures in a mixed-model statistical analysis to compare amygdala volumes between groups over time while covarying for total brain volume.
  
  
  RESULTS
  Amygdala volumes were significantly smaller in adolescents and young adults with BD compared with healthy participants (p = 0.018). The effect of time was not significant.
  
  
  CONCLUSIONS
  Although the sample size is modest, this study provides preliminary evidence to support the presence of decreased amygdala volumes in adolescents and young adults with BD that persist during this developmental epoch.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA. hilary.blumberg@yale.edu
authors.forename: Hilary P
authors.initials: HP
authors.lastname: Blumberg
authors.forename: Carolyn
authors.initials: C
authors.lastname: Fredericks
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Jessica H
authors.initials: JH
authors.lastname: Kalmar
authors.forename: Linda
authors.initials: L
authors.lastname: Spencer
authors.forename: Xenophon
authors.initials: X
authors.lastname: Papademetris
authors.forename: Brian
authors.initials: B
authors.lastname: Pittman
authors.forename: Andres
authors.initials: A
authors.lastname: Martin
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Peterson
authors.forename: Robert K
authors.initials: RK
authors.lastname: Fulbright
authors.forename: John H
authors.initials: JH
authors.lastname: Krystal
mesh_terms: D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000473:pathology*; D001714:Bipolar Disorder / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male