title: Increased hippocampal, thalamus and amygdala volume in long-term lithium-treated bipolar I disorder patients compared with unmedicated patients and healthy subjects.
abstract: Magnetic resonance imaging (MRI) studies in bipolar I disorder (BD-I) suggest that lithium is associated with increased volumes of cortico-limbic structures. However, more rigorous control of confounding factors is needed to obtain further support for this hypothesis. The aim of the present study was to assess differences in brain volumes among long-term lithium-treated BD-I patients, unmedicated BD-I patients, and healthy controls.
  
  
  
  This was a cross-sectional study with 32 euthymic BD-I patients (16 on lithium monotherapy for a mean of 180 months, and 16 receiving no medication for at least the 2 months prior to the study) and 20 healthy controls. Patients were euthymic (Hamilton Depression Rating Scale [HDRS] <6 and Young Mania Rating Scale [YMRS] <7) and had not taken psychotropic medications other than lithium for at least 6 months. Brain images were acquired on a 1.5 Tesla MRI (Phillips, Amsterdam, The Netherlands) and segmented to generate volumetric measures of cortical and subcortical brain areas, ventricles and global brain.
  
  
  
  Significant differences were found in the volumes of the left amygdala (P=.0003), right amygdala (P=.030), left hippocampus (P=.022), left thalamus (P=.022), and right thalamus (P=.019) in long-term lithium-treated BD-I patients, compared to unmedicated patients and controls, after multivariable adjustment. No differences were observed in global brain volume or in ventricular size among the three groups. Likewise, there was no correlation between serum lithium levels and the increase in size in the described brain areas.
  
  
  
  The structural differences found among the three groups, and specifically those between long-term lithium-treated and unmedicated BD-I patients, indicate increased limbic structure volumes in lithium-treated patients.
authors.affiliation: Research Group in Psychiatry GIPSI, Department of Psychiatry, Faculty of Medicine, Universidad de Antioquia, Medellin, Colombia.
authors.forename: Carlos
authors.initials: C
authors.lastname: López-Jaramillo
authors.affiliation: Research Group in Psychiatry GIPSI, Department of Psychiatry, Faculty of Medicine, Universidad de Antioquia, Medellin, Colombia.
authors.forename: Cristian
authors.initials: C
authors.lastname: Vargas
authors.affiliation: Research Group in Psychiatry GIPSI, Department of Psychiatry, Faculty of Medicine, Universidad de Antioquia, Medellin, Colombia.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Díaz-Zuluaga
authors.affiliation: Research Group in Psychiatry GIPSI, Department of Psychiatry, Faculty of Medicine, Universidad de Antioquia, Medellin, Colombia.
authors.forename: Juan David
authors.initials: JD
authors.lastname: Palacio
authors.affiliation: Research Group, Instituto de Alta Tecnología Médica IATM, Medellin, Colombia.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Castrillón
authors.affiliation: Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, CA, USA.
authors.forename: Carrie
authors.initials: C
authors.lastname: Bearden
authors.affiliation: Department of Psychiatry, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Barcelona, Spain.
authors.forename: Eduard
authors.initials: E
authors.lastname: Vieta
mesh_terms: D000328:Adult; D000679:Amygdala / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D018692:Antimanic Agents / Q000008:administration & dosage / Q000009:adverse effects; D001714:Bipolar Disorder / Q000175:diagnosis / Q000188:drug therapy; D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D006801:Humans; D008094:Lithium / Q000008:administration & dosage / Q000009:adverse effects; D000069451:Long Term Adverse Effects / Q000175:diagnosis / Q000209:etiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009929:Organ Size / Q000187:drug effects; D013788:Thalamus / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology
chemical_list: D018692:Antimanic Agents; D008094:Lithium
keywords: bipolar disorder; brain volume; lithium; neuroimaging