The Metacognitive Processes of Decentering Scale: Development and initial validation of trait and state versions.

The ability to decenter from internal experiences is important for mental health. Consequently, improving decentering is a common therapeutic target, particularly for mindfulness-based interventions. However, extant decentering measures are limited as they fail to directly assess all 3 metacognitive processes recently theorized to subserve decentering. We thus conducted 4 studies to develop and test the Metacognitive Processes of Decentering-Trait (MPoD-t) and State (MPoD-s) scales. Consistent with the metacognitive processes model, exploratory factor analysis (N = 355) and then bifactor exploratory structural equation modeling (N = 275) indicated the MPoD-t was composed of three independent yet interrelated lower-order factors, metaawareness, (dis)identification with internal experience, and (non)reactivity to internal experience, which subserved an emergent, higher-order, decentering factor. We next found evidence of the MPoD-t's convergent validity; as well as known-groups criterion validity, wherein mindfulness practitioners reported higher MPoD-t scores than nonpractitioners. Item response theory analyses were then used to identify a subset of 3 MPoD-t items for the MPoD-s. Finally, we found evidence that the MPoD-s was sensitive to changes in state decentering following a brief mindfulness induction relative to an active control condition; and that MPoD-s changes mediated the effect of mindfulness on levels of pain and related outcomes among a sample of preoperative surgery patients (N = 82). These studies indicate the trait and state versions of the MPoD may prove useful for the study of decentering and its constituent metacognitive processes. As such, the MPoD may help advance our understanding of how the metacognitive processes of decentering support mental health and well-being. (PsycInfo Database Record (c) 2020 APA, all rights reserved).