title: Neuroanatomical correlates of genetic risk for bipolar disorder: A voxel-based morphometry study in bipolar type I patients and healthy first degree relatives.
abstract: BACKGROUND
  Bipolar disorder (BD) is a highly heritable mental illness which is associated with neuroanatomical abnormalities. Investigating healthy individuals at high genetic risk for bipolar disorder may help to identify neuroanatomical markers of risk and resilience without the confounding effects of burden of illness or medication.
  
  
  METHODS
  Structural magnetic resonance imaging scans were acquired from 30 euthymic patients with BD-I (BP), 28 healthy first degree relatives of BD-I patients (HR), and 30 healthy controls (HC). Data was analyzed using DARTEL for voxel based morphometry in SPM8.
  
  
  RESULTS
  Whole-brain analysis revealed a significant main effect of group in the gray matter volume in bilateral inferior frontal gyrus, left parahippocampal gyrus, left lingual gyrus and cerebellum, posterior cingulate gyrus, and supramarginal gyrus (alphasim corrected (≤0.05 FWE)). Post-hoc t-tests showed that inferior frontal gyrus volumes were bilaterally larger both in BP and HR than in HC. BP and HR also had smaller cerebellar volume compared with HC. In addition, BP had smaller left lingual gyrus volume, whereas HR had larger left parahippocampal and supramarginal gyrus volume compared with HC.
  
  
  CONCLUSIONS
  This study was cross-sectional and the sample size was not large. All bipolar patients were on medication, therefore we were not able to exclude medication effects in bipolar group in this study.
  
  
  CONCLUSIONS
  Our findings suggest that increased inferior frontal gyrus and decreased cerebellar volumes might be associated with genetic predisposition for bipolar disorder. Longitudinal studies are needed to better understand the predictive and prognostic value of structural changes in these regions.
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Izmir Katip Celebi University, Ataturk Training and Research Hospital, Izmir, Turkey; Department of Neuroscience, Health Sciences Institute, Dokuz Eylul University, Izmir, Turkey. Electronic address: aybala.saricicek@gmail.com.
authors.forename: Aybala
authors.initials: A
authors.lastname: Sarıçiçek
authors.affiliation: Department of Neuroscience, Health Sciences Institute, Dokuz Eylul University, Izmir, Turkey; Department of Psychiatry, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Nefize
authors.initials: N
authors.lastname: Yalın
authors.affiliation: Department of Neuroscience, Health Sciences Institute, Dokuz Eylul University, Izmir, Turkey; Department of Psychology, Faculty of Arts and Sciences, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Ceren
authors.initials: C
authors.lastname: Hıdıroğlu
authors.affiliation: Department of Neuroscience, Health Sciences Institute, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Berrin
authors.initials: B
authors.lastname: Çavuşoğlu
authors.affiliation: Department of Psychology, Faculty of Humanities and Social Sciences, Uskudar University, Istanbul, Turkey.
authors.forename: Cumhur
authors.initials: C
authors.lastname: Taş
authors.affiliation: Department of Neuroscience, Health Sciences Institute, Dokuz Eylul University, Izmir, Turkey; Psychiatry Clinic, Gümüşhane State Hospital, Gümüşhane, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Ceylan
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Izmir Katip Celebi University, Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Nabi
authors.initials: N
authors.lastname: Zorlu
authors.affiliation: Department of Radiology, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Emel
authors.initials: E
authors.lastname: Ada
authors.affiliation: Department of Neuroscience, Health Sciences Institute, Dokuz Eylul University, Izmir, Turkey; Department of Psychiatry, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Zeliha
authors.initials: Z
authors.lastname: Tunca
authors.affiliation: Department of Neuroscience, Health Sciences Institute, Dokuz Eylul University, Izmir, Turkey; Department of Psychiatry, Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Ayşegül
authors.initials: A
authors.lastname: Özerdem
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000235:genetics* / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D058068:Endophenotypes; D005190:Family; D005192:Family Health; D005260:Female; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D012307:Risk Factors; D055815:Young Adult
keywords: Bipolar disorder; Cerebellum; Endophenotype; Inferior frontal gyrus; Voxel based morphometry