Psychometric validation, factor structure, and measurement invariance of the Arabic brief existential loneliness scale

Introduction Existential loneliness signifies a profound feeling of fundamental separation from others and the world, increasingly acknowledged in the scholarly literature. The Arabic psychological literature lacks the necessary instruments to assess this construct. Methods The objective of the current study was to develop an Arabic version of the Brief Scale of Existential Loneliness (BSEL). Psychometric validation included internal consistency, test–retest reliability, and validity. The factor structure of the scale was assessed using exploratory factor analysis and confirmatory factor analysis with 420 participants (aged 18–82 years; M = 35.7, SD = 15.3), followed by assessing measurement invariance across gender and age groups. Results The results showed excellent internal consistency reliability (alpha and omega) and adequate stability. BSEL scores had a positive correlation with depression and existential isolation and a negative correlation with happiness, thus indicating convergent–divergent validity of the scale. The BSEL score showed a negative correlation to age. A unidimensional factor structure was supported. Strict measurement invariance was established across genders, whereas scalar invariance was supported across age groups. Discussion The results suggest that the Arabic version of the BSEL is a promising and user-friendly tool for assessing existential loneliness among native Arabic speakers.