... In keeping with Fournier and colleagues (2023), we compare a traditional one-factor model, which has shown some support in the literature (e.g., Ballarotto, Marzilli, et al., 2021;Ballarotto, Volpi, & Tambelli, 2021), to a two-factor model distinguishing between two components of problematic social media use: a primary dimension indicating non-pathological high engagement in the platform (i.e., tolerance and salience symptoms) and a secondary dimension reflecting addiction-like symptoms such as relapse, withdrawal, conflict, and mood modification. In order to establish the construct validity of the emerging model, we explore associations with various psychological correlates, including Big Five personality traits (i.e., Extraversion, Agreeableness, Conscientiousness, Neuroticism, Openness), depression (PHQ-8; Mazzotti et al., 2003), difficulties in emotional regulation (DERS; Gratz & Roemer, 2004), loneliness (Hughes et al., 2004), Fear of Missing Out (FoMO; Przybylski et al., 2013), and motives for Instagram use (Social Interaction, Documentation, Self-Promotion, Diversion, Creativity; Sheldon & Newman, 2019). These specific measures are examined in alignment with the Interaction of Person-Affect-Cognition-Execution (I-PACE) model (Brand et al., 2016;Young & Brand, 2017), which posits that individual predispositions (such as personality traits and usage motives), affective responses (such as emotional regulation difficulties, depression, loneliness) and cognitive biases (such as FoMO), all contribute to influence problematic internet use behaviors, including those involving social media use. ...