title: Cortical folding in patients with bipolar disorder or unipolar depression.
abstract: BACKGROUND
  Analysis of cortical folding may provide insight into neurodevelopment deviations, which, in turn, can predispose to depression that responds particularly poorly to medications. We hypothesized that patients with treatment-resistant depression would exhibit measurable alterations in cortical folding.
  
  
  METHODS
  We computed hemispheric global sulcal indices (g-SIs) in T(1)-weighted magnetic resonance images obtained from 76 patients and 70 healthy controls. We separately searched for anatomic deviations in patients with bipolar disorder (16 patients with treatment-resistant depression, 25 with euthymia) and unipolar depression (35 patients with treatment-resistant depression).
  
  
  RESULTS
  Compared with healthy controls, both groups of patients with treatment-resistant depression exhibited reduced g-SIs: in the right hemisphere among patients with bipolar disorder and in both hemispheres among those with unipolar depression. Patients with euthymic bipolar disorder did not differ significantly from depressed patients or healthy controls. Among patients with bipolar disorder who were taking lithium, we found positive correlations between current lithium dose and g-SIs in both hemispheres.
  
  
  CONCLUSIONS
  We cannot estimate the extent to which the observed g-SI reductions are linked to treatment resistance and to what extent they are state-dependent. Furthermore, we cannot disentangle the impact of medications from that of the affective disorder. Finally, there is interindividual variation and overlap of g-SIs among patients and healthy controls that need to be considered when interpreting our results.
  
  
  CONCLUSIONS
  Reduced global cortical folding surface appears to be characteristic of patients with treatment-resistant depression, either unipolar or bipolar. In patients with bipolar disorder, treatment with lithium may modify cortical folding surface.
authors.affiliation: INSERM, U797 Research Unit Neuroimaging & Psychiatry, CEA, Hospital Department Frédéric Joliot & Neurospin, Paris Sud University, Orsay, France.
authors.forename: Jani
authors.initials: J
authors.lastname: Penttilä
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Paillère-Martinot
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Martinot
authors.forename: Damien
authors.initials: D
authors.lastname: Ringuenet
authors.forename: Michèle
authors.initials: M
authors.lastname: Wessa
authors.forename: Josselin
authors.initials: J
authors.lastname: Houenou
authors.forename: Thierry
authors.initials: T
authors.lastname: Gallarda
authors.forename: Frank
authors.initials: F
authors.lastname: Bellivier
authors.forename: André
authors.initials: A
authors.lastname: Galinowski
authors.forename: Pascale
authors.initials: P
authors.lastname: Bruguière
authors.forename: François
authors.initials: F
authors.lastname: Pinabel
authors.forename: Marion
authors.initials: M
authors.lastname: Leboyer
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Olié
authors.forename: Edouard
authors.initials: E
authors.lastname: Duchesnay
authors.forename: Eric
authors.initials: E
authors.lastname: Artiges
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Mangin
authors.forename: Arnaud
authors.initials: A
authors.lastname: Cachia
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use; D018692:Antimanic Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000473:pathology* / Q000523:psychology; D002540:Cerebral Cortex / Q000473:pathology*; D003866:Depressive Disorder / Q000473:pathology* / Q000523:psychology; D004351:Drug Resistance; D004565:Electroconvulsive Therapy; D005260:Female; D007839:Functional Laterality; D006801:Humans; D016651:Lithium Carbonate / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales
chemical_list: D000928:Antidepressive Agents; D018692:Antimanic Agents; D016651:Lithium Carbonate