Depersonalization and depressive symptoms in two online samples: development and initial validation of a short Depersonalization Mechanism Scale.

BACKGROUND: Depersonalization can be conceptualized as an emotion regulation mechanism that may emerge in response to prolonged stress and overstimulation. Individuals differ in their tendency to rely on this mechanism, with varying levels of depersonalization experiences observed in the general population. The present study aimed to develop and validate a brief version of Depersonalization Mechanism Scale. Scale reduction was undertaken to improve measurement efficiency and reduce respondent burden while preserving adequate coverage of the underlying construct. Additionally, associations between depersonalization and depressive symptoms were examined. METHODS: Two independent samples from the general Polish population participated in the study. Study 1 included 204 adults aged 22-86 years, whereas Study 2 included 367 adults aged 19-30 years. Following an initial item reduction procedure informed by psychometric and content-related considerations, the factor structure of the shortened DMS was examined using exploratory factor analysis in Study 1 and confirmatory factor analysis in Study 2. Participants completed a brief version of Depersonalization Mechanism Scale (DMS), Patient Health Questionnaire (PHQ-9), and Occupational Depression Inventory (ODI). RESULTS: The final version of the DMS comprised 14 items grouped into two subscales: Detachment and Emotional Numbness. The abbreviated scale demonstrated high internal consistency and retained the theoretical structure of the original measure. Confirmatory factor analysis supported both a two-factor and a bifactor representation of the scale. Correlation and regression analysis indicated that the depersonalization mechanism is significantly associated with depressive symptoms. CONCLUSIONS: The findings support the reliability and validity of the shortened DMS for examining depersonalization as an emotion regulation mechanism. Depersonalization was strongly associated with depressive symptoms in a non-clinical sample, highlighting its relevance to emotional functioning. The brief format of the 14-item DMS may facilitate future research on depersonalization in large-scale and multivariate studies.