To improve the health status of teachers, there is a need for good and reliable instruments to continuously assess their mental health. The current study proposed the GHQ-12 questionnaire as an appropriate instrument for measuring the mental health of teachers. The GHQ-12 is a well-established screening instrument that has mostly been applied in non-teaching samples. In the current study, the psychometric properties of the questionnaire were analyzed using a large sample of German teachers (N = 3996). The data was collected yearly over an extended period of time (2012-2020). Results showed good to very good reliability, as well as high correspondence to burnout and life satisfaction scales. Principal axis factor analysis supported a two-factor structure: Factor 1 represents "depression/stress" and Factor 2 represents "loss of confidence". However, the mental health of the investigated teachers was worse than that of a representative sample in Germany. Consequently, this study highlighted the fact that the teaching profession is vulnerable to mental strain and underlined the importance of promoting prevention programs that could help to sustain and foster the mental health of teachers. In this context, the GHQ-12 could be proposed as a good and economic tool to assess and analyze mental health in German teachers. The presented norm could help practitioners and teachers to compare individual scores within a larger peer group.
Keywords: burnout; culture; factor structure; mental health; prevention; teacher.