Spanish validation of two social media appearance-related constructs associated with disordered eating in adolescents: The Appearance-related Social Media Consciousness scale (ASMC) and the Critical Thinking about Media Messages scale (CTMM).

Appearance-related constructs underlying social media are negatively associated with mental health. However, their impact on the Spanish population is still unexplored. The present study aimed to validate the Spanish versions of two appearance-related scales: (1) the appearance-related social media consciousness (ASMC) scale; and (2) the critical thinking about media messages (CTMM) scale. Translation and cultural adaptation of the scales were carried out. The scales' psychometric properties were assessed using exploratory and confirmatory factor analyses, measurement invariance across gender (boys vs. girls) and age groups (early adolescents vs. middle adolescents), internal consistency, and convergent validity. The sample included 803 Spanish secondary school adolescents aged between 12 and 18 (M = 15.1, 47.9% girls, 47.2% boys, 4.9% non-binary gender/others). The exploratory factor analyses replicated original one-factor structures of both scales, which was verified using confirmatory factor analysis. Regarding the ASMC Scale, a re-specified model (allowing for error correlations between Items 1-2) presented an adequate fit. Both models were invariant across gender and age groups. Excellent internal consistency was found. Bivariate correlations between the ASMC and eating disorders related variables (body esteem, disordered eating, self-esteem, sociocultural attitudes towards appearance, and general mental health) supported its convergent validity and proved ASMC to be a potential target for future preventive eating disorder interventions. However, the CTMM scale correlated only with sociocultural pressures, thus, further research is needed to assess the validity of the CTMM in Spanish samples.