title: Defining clinical severity in adults with obsessive-compulsive disorder.
abstract: OBJECTIVE
  The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is the most commonly used instrument to assess the clinical severity of obsessive-compulsive symptoms. Treatment determinations are often based on Y-BOCS score thresholds. However, these benchmarks are not empirically based, which may result in non-evidence based treatment decisions. Accordingly, the present study sought to derive empirically-based benchmarks for defining obsessive-compulsive symptom severity.
  
  
  METHODS
  Nine hundred fifty-four adult patients with obsessive-compulsive disorder (OCD), recruited through the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders, were evaluated by experienced clinicians using a structured clinical interview, the Y-BOCS, and the Clinical Global Impressions-Severity scale (CGI-Severity).
  
  
  RESULTS
  Similar to results in treatment-seeking children with OCD, our findings demonstrated convergence between the Y-BOCS and global OCD severity assessed by the CGI-Severity (Nagelkerke R(2)=.48). Y-BOCS scores of 0-13 corresponded with 'mild symptoms' (CGI-Severity=0-2), 14-25 with 'moderate symptoms' (CGI-Severity=3), 26-34 with 'moderate-severe symptoms' (CGI-Severity=4) and 35-40 with 'severe symptoms' (CGI-Severity=5-6). Neither age nor ethnicity was associated with Y-BOCS scores, but females demonstrated more severe obsessive-compulsive symptoms than males (d=.34). Time spent on obsessions/compulsions, interference, distress, resistance, and control were significantly related to global OCD severity although the symptom resistance item pairing demonstrated a less robust relationship relative to other components of the Y-BOCS.
  
  
  CONCLUSIONS
  These data provide empirically-based benchmarks on the Y-BOCS for defining the clinical severity of treatment seeking adults with OCD, which can be used for normative comparisons in the clinic and for future research.
authors.affiliation: Department of Pediatrics, University of South Florida, St. Petersburg, FL, United States; Department of Health Policy & Management, University of South Florida, Tampa, FL, United States; Rogers Behavioral Health-Tampa Bay, Tampa, FL, United States; All Children's Hospital-Johns Hopkins Medicine, St. Petersburg, FL, United States. Electronic address: estorch@health.usf.edu.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Storch
authors.affiliation: Department of Pediatrics, University of South Florida, St. Petersburg, FL, United States.
authors.forename: Alessandro S
authors.initials: AS
authors.lastname: De Nadai
authors.affiliation: Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Maria
authors.initials: M
authors.lastname: Conceição do Rosário
authors.affiliation: Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Roseli G
authors.initials: RG
authors.lastname: Shavitt
authors.affiliation: Department of Neurology, Psychology and Psychiatry, Botucatu Medical School, Univ Estadual Paulista, São Paulo, Brazil.
authors.forename: Albina R
authors.initials: AR
authors.lastname: Torres
authors.affiliation: Department of Psychiatry, Health Sciences Federal University of Porto Alegre, Porto Alegre, Brazil.
authors.forename: Ygor A
authors.initials: YA
authors.lastname: Ferrão
authors.affiliation: Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Euripedes C
authors.initials: EC
authors.lastname: Miguel
authors.affiliation: Department of Pediatrics, University of South Florida, St. Petersburg, FL, United States; All Children's Hospital-Johns Hopkins Medicine, St. Petersburg, FL, United States.
authors.forename: Adam B
authors.initials: AB
authors.lastname: Lewin
authors.affiliation: Anxiety and Obsessive-Compulsive Spectrum Research Program, Institute of Psychiatry, Federal University of Rio de Janeiro & D'Or Institute for Research and Education, Rio de Janeiro, Brazil.
authors.forename: Leonardo F
authors.initials: LF
authors.lastname: Fontenelle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult