Validity of the 12-item General Health Questionnaire (GHQ-12) in detecting depressive and anxiety disorders among high school students.

Despite the common use of the 12-item General Health Questionnaire (GHQ-12) with adolescents, there is limited data supporting its validity with this population. The aims of the study were to investigate the psychometric properties of the GHQ-12 among high school students, to validate the GHQ-12 against the gold standard of a diagnostic interview, and to suggest a threshold score for detecting depressive and anxiety disorders. Six hundred and fifty-four high school students from years 10 to 12 (ages 15-18) completed the GHQ-12 (Likert scored) and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-IV-Test Revision (DSM-IV-TR). Receiver operating characteristic (ROC) curves were plotted. The mean GHQ-12 score for the total sample was 9.9 (S.D.=5.4). Results from the ROC curve indicated that the GHQ-12 performed better than chance at identifying depressive and anxiety disorders (area under the curve (AUC)=0.781). A GHQ-12 threshold score of 9/10 for males and 10/11 for females was found to be optimal. Given the significant proportion of mental illness among high school students, there may be a need to introduce screening for mental illnesses as part of the school curriculum. This can assist with the early identification and enable low stigma preventive intervention within the school environment.