Psychometric Evaluation of the Trait-State FoMO Scale in a Turkish University Sample: Validity, Reliability, and Invariance Across Groups

Fear of Missing Out (FoMO) has received growing attention among university students; however, Turkish instruments assessing both trait and state FoMO remain limited. This study adapted the Trait-State Fear of Missing Out Scale (T-SFoMOS) into Turkish and evaluated its reliability, validity, and measurement invariance. A total of 614 Turkish undergraduates completed an online survey including the T-SFoMOS, the Bergen Social Media Addiction Scale, and the Positive and Negative Affect Schedule. The Turkish T-SFoMOS showed strong internal consistency (α = 0.839 for trait, α = 0.858 for state, α = 0.899 for total) and good construct validity, supporting a two-factor trait–state structure (TLI = 0.981; SRMR = 0.062). Scalar invariance was established across gender and time spent on social media. Higher T-SFoMOS scores were associated with greater social media addiction and negative affect, supporting concurrent validity. Overall, the Turkish T-SFoMOS appears to be a reliable and valid instrument for assessing trait and state FoMO among Turkish university students.