title: Obsessive-compulsive symptoms and obsessive-compulsive disorder in adolescents: a population-based study.
abstract: OBJECTIVE
  To estimate the prevalence of obsessive-compulsive symptoms (OCS) and disorder (OCD) among adolescents and to describe OCD characteristics according to gender.
  
  
  METHODS
  Participants were selected by cluster sampling at seven high-schools in southern Brazil. In the first stage, 2,323 students were screened for OCS; in the second stage, adolescents scoring ≥ 21 on the OCI-R scale were individually interviewed. OCD diagnosis was established using a semi-structured interview (Schedule for Affective Disorders and Schizophrenia for School Aged Children: Present and Lifetime Version - K-SADS-PL).
  
  
  RESULTS
  The past-month estimated prevalence of OCS was 18.3%, and the point estimated prevalence of OCD, 3.3%. Girls showed higher scores (OCS: 24.8 vs. 14.4%; OCD: 4.9 vs. 1.4%; p < 0.001). Only 9.3% of OCD adolescents had been diagnosed and 6.7% received treatment. The most frequent/severe DY-BOCS dimensions were miscellaneous (86.7%; mean score 6.3 ± 3.8) and symmetry (85.3%; 5.9 ± 3.8). Female OCD adolescents predominantly showed depression (p = 0.032), and male adolescents, tic disorders (p = 0.006).
  
  
  CONCLUSIONS
  OCD is underdiagnosed in adolescents, and few are treated. Future studies should investigate the relationship between OCS and the onset of OCD.
authors.affiliation: Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Analise de Souza
authors.initials: Ade S
authors.lastname: Vivan
authors.affiliation: School of Psychology, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Lidiane
authors.initials: L
authors.lastname: Rodrigues
authors.affiliation: School of Psychology, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Wendt
authors.affiliation: Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Mônica Giaretton
authors.initials: MG
authors.lastname: Bicca
authors.affiliation: Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Daniela Tusi
authors.initials: DT
authors.lastname: Braga
authors.affiliation: Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Aristides Volpato
authors.initials: AV
authors.lastname: Cordioli
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000367:Age Factors; D001008:Anxiety Disorders / Q000453:epidemiology; D001938:Brazil / Q000453:epidemiology; D015897:Comorbidity; D003866:Depressive Disorder / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000453:epidemiology*; D011569:Psychiatric Status Rating Scales; D017678:Sex Distribution; D012737:Sex Factors