title: The factor structure of the Strengths and Difficulties Questionnaire (SDQ) in Greek adolescents.
abstract: BACKGROUND
  The Strengths and Difficulties Questionnaire (SDQ) is a practical, economic and user-friendly screening instrument of emotional and behavioural problems in children and adolescents. This study was aimed primarily at evaluating the factor structure of the Greek version of the SDQ.
  
  
  METHODS
  A representative nationwide sample of 1,194 adolescents (11 to 17 years old) completed the questionnaire. Confirmatory factor analysis (CFA) was conducted to assess the factor structure of the SDQ.
  
  
  RESULTS
  CFA supported the original five-factor structure. The modification of the model provided some improvements. Internal consistency was acceptable for total difficulties, emotional symptoms and prosocial behaviour scale, moderate for hyperactivity/inattention scale and inadequate for peer and conduct problems scale. Older adolescents (aged 15 to 17 years) reported more hyperactivity/inattention and conduct problems than younger ones (aged 11 to 14 years) and girls reported more emotional symptoms and less prosocial behaviour problems than boys. Adolescents of low socioeconomic status (SES) reported more difficulties than those of medium and high SES.
  
  
  CONCLUSIONS
  The Greek SDQ could be potentially considered as a community-wide screening instrument for adolescents' emotional and behavioural problems.
authors.affiliation: Centre for Health Services Research, Department of Hygiene, Epidemiology and Medical Statistics, Athens University Medical School, Athens, Greece. g_p_giann@yahoo.gr
authors.forename: George
authors.initials: G
authors.lastname: Giannakopoulos
authors.forename: Chara
authors.initials: C
authors.lastname: Tzavara
authors.forename: Christine
authors.initials: C
authors.lastname: Dimitrakaki
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Kolaitis
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Rotsika
authors.forename: Yannis
authors.initials: Y
authors.lastname: Tountas