title: Factor structure of the Iranian version of 12-item general health questionnaire.
abstract: BACKGROUND
  The 12-Item General Health (GHQ-12) questionnaire is one of the most commonly used instruments in screening studies on mental health.
  
  
  OBJECTIVE
  The current study aimed to examine the factor structure of the GHQ-12 questionnaire among the students in Iran.
  
  
  METHODS
  It was a cross-sectional study in which 428 university students were recruited and completed the GHQ-12. Reliability of the GHQ-12 was evaluated using the Cronbach's alpha and the split-half method by applying the Spearman-Brown coefficient. Factor structure of the questionnaire was extracted by exploratory factor analysis (EFA). Confirmatory factor analysis (CFA) was conducted to assess how well the EFA extracted model fitted the observed data.
  
  
  RESULTS
  The mean age of the participants was 22.83 years (SD = 3.09). Most of them were female (56.1%) and 81% were unemployed. The Cronbach's alpha coefficient for the Iranian version of GHQ-12 was 0.85. Using the split-half method, the alpha for the social dysfunction was found to be 0.77; it was 0.76 for the psychological distress. The principal component analysis revealed a two-factor structure for the questionnaire including social dysfunction and psychological distress that explained 48% of the observed variances. The confirmatory factor analysis was showed fit for the data.
  
  
  CONCLUSIONS
  The current study findings confirm that the Iranian version of GHQ-12 has a good factor structure and is a reliable and valid instrument to measure psychological distress and social dysfunction.
authors.affiliation: Health Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Rahmati Najarkolaei
authors.affiliation: Behavioral Sciences Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Raiisi
authors.affiliation: Department of Midwifery, Faculty of Nursing and Midwifery, Shahed University, Tehran, IR Iran.
authors.forename: Parvin
authors.initials: P
authors.lastname: Rahnama
authors.affiliation: Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Gholami Fesharaki
authors.affiliation: Regional Knowledge Hub for HIV/AIDS Surveillance, Kerman University of Medical Sciences, Kerman, IR Iran.
authors.forename: Omid
authors.initials: O
authors.lastname: Zamani
authors.affiliation: Islamic Azad University, Saveh Branch, Saveh, IR Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Jafari
authors.affiliation: Mental Health Research Group, Health Metrics Research Centre, Iranian Institute for Health Sciences Research, Academic Center for Education Culture & Research (ACECR), Tehran, IR Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Montazeri
keywords: Construct Validity; General Health Questionnaire; Mental Health