title: ORBITOFRONTAL THICKNESS AS A MEASURE FOR TREATMENT RESPONSE PREDICTION IN OBSESSIVE-COMPULSIVE DISORDER.
abstract: BACKGROUND
  Early prediction of treatment response could reduce exposure to ineffective treatments and optimize the use of medical resources. Neuroimaging techniques have been used to identify biomarkers that are predictive of outcomes. The aims of this study were to investigate orbitofrontal cortex (OFC) thickness as a potential morphometric biomarker to discriminate outcomes in obsessive-compulsive disorder (OCD) and then to reexamine this biomarker in an independent cohort
  
  
  METHODS
  Using a logistic regression model based on the mean baseline thickness of subregions of the OFC, we estimated the probability of treatment response in 29 treatment-naïve OCD patients who participated in a clinical trial. That algorithm was then tested in an independent cohort of 12 patients with a confirmed diagnosis of refractory OCD RESULTS: Among the treatment-naïve OCD patients, measures of OFC thickness statistically significantly differentiated responders (n = 13) and nonresponders (n = 16), with an overall classification accuracy of ≈80%, a sensitivity of 77% (10/13), and a specificity of 81% (13/16). Of the refractory OCD patients in the second independent cohort, 67% were correctly classified as nonresponders. The most discriminative measures in the initial cohort of treatment-naïve patients were the thicknesses of the left and right medial OFC (P = .009 and P = .028, respectively)
  
  
  CONCLUSIONS
  We found OFC thickness to be a strong predictor of treatment response in treatment-naïve OCD patients. Although there are not yet any brain imaging biomarkers with clinical utility, our results highlight the potential of these measures as tools for predicting treatment outcomes in OCD.
authors.affiliation: Department of Psychiatry, Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil.|Department of Psychiatry, Interdisciplinary Laboratory for Clinical Neuroscience, Federal University of São Paulo, São Paulo, Brazil.|Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Marcelo Q
authors.initials: MQ
authors.lastname: Hoexter
authors.affiliation: Department of Psychiatry, Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Juliana B
authors.initials: JB
authors.lastname: Diniz
authors.affiliation: Department of Psychiatry, Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Lopes
authors.affiliation: Department of Psychiatry, Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Marcelo C
authors.initials: MC
authors.lastname: Batistuzzo
authors.affiliation: Department of Psychiatry, Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Roseli G
authors.initials: RG
authors.lastname: Shavitt
authors.affiliation: Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Darin D
authors.initials: DD
authors.lastname: Dougherty
authors.affiliation: Department of Psychiatry, Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Fabio L S
authors.initials: FL
authors.lastname: Duran
authors.affiliation: Department of Psychiatry, Interdisciplinary Laboratory for Clinical Neuroscience, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Bressan
authors.affiliation: Department of Psychiatry, Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Geraldo F
authors.initials: GF
authors.lastname: Busatto
authors.affiliation: Department of Psychiatry, Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Euripides C
authors.initials: EC
authors.lastname: Miguel
authors.affiliation: Center of Mathematics, Computation, and Cognition, Federal University of the ABC, Santo André, Brazil.
authors.forename: Joao R
authors.initials: JR
authors.lastname: Sato
mesh_terms: D000328:Adult; D001931:Brain Mapping; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000473:pathology* / Q000628:therapy*; D009929:Organ Size; D011237:Predictive Value of Tests; D017397:Prefrontal Cortex / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
keywords: decision support techniques; logistic models; magnetic resonance imaging; neuroimaging; treatment outcome