Objectives: The aim of the study was to assess the convergent and divergent validity, reliability, utility, and treatment sensitivity of a newly translated German version of the Southampton Mindfulness Questionnaire (SMQ). The SMQ is a 16-item instrument measuring mindful awareness of distressing thoughts, images, and perceptions, developed originally within the mindfulness for psychosis field.
Methods: Overall, three studies were conducted, comprising (1) a non-clinical sample of n = 848 (638 community sample and 210 meditators); (2) a clinical sample of n = 213 (106 schizophrenia and 107 depression); and (3) a clinical sample with n = 122 participants with emotional disorders within a randomized controlled study, of which 30 participants were also included in study 2. To assess convergent validity, participants completed the SMQ, Freiburg Mindfulness Inventory (FMI), and Comprehensive Inventory of Mindfulness Experiences (CHIME). To measure divergent validity, participants completed the Brief Symptom Inventory 18 (BSI-18), Positive and Negative Affect Schedule (PANAS), Brief Experiential Avoidance Questionnaires (BEAQ), and Anxiety Sensitivity Index 3 (ASI-3).
Results: Mean internal consistency (α = 0.89) and convergent (r = 0.66 to 0.73) and divergent validity (r = − 0.09 to − 0.50) were established and sensitivity to change over time following treatment (d = 0.86) was shown. For the clinical sample, a single-factor structure is suggested by principal component analysis.
Conclusions: Results provide first evidence for the utility of the German version of the SMQ for clinical practice and research in healthy individuals, meditators, and clinical groups. Further research is needed to examine the underlying construct of mindfulness.