Factor structure and internal consistency of the Greek version of the General Health Questionnaire - 28 (GHQ-28)

The General Health Questionnaire - 28 (GHQ-28) is one of the most widely used screening instruments for psychiatric disorders. The aim of the present study was to examine the factor structure and the internal consistency of the Greek GHQ-28 in a sample of 501 university students (302 females; Mage = 20.5 years). Confirmatory factor analysis (CFA) did not provide an optimal fit for the original four-factor structure. Therefore, exploratory factor analysis (EFA) and principal component analysis (PCA) were conducted in search of alternative models with optimal fit. Models obtained from EFA and PCA were compared through further CFA. The model derived from EFA was the best-fitting solution and yielded three factors: Anxiety/Somatic Complaints (a unified factor), Social Dysfunction, and Severe Depression. In addition, internal consistency assessed through Cronbach's alpha was acceptable for all subscales both in the four- and in the new three-factor model. Possible explanations for the differentiations found in the structure of the Greek GHQ-28 are discussed in the framework of the existing literature on the use of this measure worldwide.