Multidimensional properties of the General Health Questionnaire.

This analysis re-examines the factor structure of the 12-item GHQ for a large Australian sample of young people. It shows that oblique factor rotation better approaches the criterion of simple structure, and allows separate components of the GHQ to be identified and measured using factor scores. When the performance of these separate factors is compared with composite Likert scores, it is found that they do not behave uniformly in response to outside variables, both in cross-sectional and longitudinal analyses. These results suggest that there are advantages to be gained by using the multidimensional properties of the GHQ as well as a single severity score. The additional information this yields can provide new insights into the nature of psychiatric impairment within and between samples.