title: Obsessive-compulsive disorder: influence of age at onset on comorbidity patterns.
abstract: OBJECTIVE
  This study investigates the influence of age at onset of OCS on psychiatric comorbidities, and tries to establish a cut-off point for age at onset.
  
  
  METHODS
  Three hundred and thirty OCD patients were consecutively recruited and interviewed using the following structured interviews: Yale-Brown Obsessive Compulsive Scale; Yale Global Tic Severity Scale and the Structured Clinical Interview for DSM-IV. Data were analyzed with regression and cluster analysis.
  
  
  RESULTS
  Lower age at onset was associated with a higher probability of having comorbidity with tic, anxiety, somatoform, eating and impulse-control disorders. Longer illness duration was associated with lower chance of having tics. Female gender was associated with anxiety, eating and impulse-control disorders. Tic disorders were associated with anxiety disorders and attention-deficit/hyperactivity disorder. No cut-off age at onset was found to clearly divide the sample in homogeneous subgroups. However, cluster analyses revealed that differences started to emerge at the age of 10 and were more pronounced at the age of 17, suggesting that these were the best cut-off points on this sample.
  
  
  CONCLUSIONS
  Age at onset is associated with specific comorbidity patterns in OCD patients. More prominent differences are obtained when analyzing age at onset as an absolute value.
authors.affiliation: Department of Psychiatry, University of Sao Paulo Medical School, Rua Dr. Ovídio Pires de Campos, 785, 05403-010 São Paulo, SP, Brazil. alicedemathis@gmail.com
authors.forename: Maria Alice
authors.initials: MA
authors.lastname: de Mathis
authors.forename: Maria Conceição
authors.initials: MC
authors.lastname: do Rosario
authors.forename: Juliana Belo
authors.initials: JB
authors.lastname: Diniz
authors.forename: Albina Rodrigues
authors.initials: AR
authors.lastname: Torres
authors.forename: Roseli Gedanki
authors.initials: RG
authors.lastname: Shavitt
authors.forename: Ygor Arzeno
authors.initials: YA
authors.lastname: Ferrão
authors.forename: Victor
authors.initials: V
authors.lastname: Fossaluza
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de Bragança Pereira
authors.forename: Eurípedes Constantino
authors.initials: EC
authors.lastname: Miguel
mesh_terms: D000328:Adult; D017668:Age of Onset; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D001938:Brazil; D015897:Comorbidity; D003430:Cross-Sectional Studies; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D001068:Feeding and Eating Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D010552:Personality Assessment; D012737:Sex Factors; D013001:Somatoform Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D013981:Tic Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology