Psychometric properties of the Positive Mental Health Scale (PMH-scale)

Justina Lukat, Jürgen Margraf, Rainer Lutz, William M. van der Veld, Eni S. Becker

In recent years, it has been increasingly recognized that the absence of mental disorder is not the same as the presence of positive mental health (PMH). With the PMH-scale we propose a short, unidimensional scale for the assessment of positive mental health. The scale consists of 9 Likert-type items. The psychometric properties of the PMH-scale were tested in a series of six studies using samples from student (n = 5406), patient (n = 1547) and general (n = 3204) populations. Factorial structure and measurement equivalence were tested with the measurement invariance testing. The factor models were analysed with the maximum likelihood procedure. Internal consistency was examined using Cronbach's alpha, test-retest reliability, convergent and divergent validity was examined by Pearson correlation. Sensitivity to (therapeutic) change was examined with the t-test. Results confirmed unidimensionality, scalar invariance across samples and over time, high internal consistency, good retest-reliability, good convergent and discriminant validity as well as sensitivity to therapeutic change. These findings suggest that the PMH-Scale indeed measures a single concept and allows us to compare scores over groups and over time. The PMH-scale thus is a brief and easy to interpret instrument for measuring PMH across a large variety of relevant groups.