Muscle Dysmorphic Disorder Inventory (MDDI): Translation and Validation of an Arabic-language version

Purpose: The term muscle dysmorphia (MD) refers to the pathological desire to increase lean muscle mass coupled with a persistent belief that one is not muscular enough. The disorder was recently classified under the umbrella of obsessive-compulsive disorder in DSM-5. The individuals social view and sense of self-worth are impacted by MD. Consequently, functional impairment occurs. The assessment of MD is made with the muscle dysmorphia Disorder Inventory (MDDI). The purpose of the study is to validate the Arabic version of the MDDI ensuring the availability of the instrument in Arabic-speaking nations. Methods 1118 participants (58% female, average age 28 years) participated in the translation of MDDI through an internet-based survey. Results Based on multigroup confirmatory factor analysis (CFA), the three-factor structure of the English MDDI was replicated, independent of gender (TLI = 0.85, CFI = 0.90, RMSEA = 0.09). The reliability was evaluated via Cronbach's α and McDonald's ω for the total MDDI scale and the sub-scales. Cronbach´s alpha was 0.71 for DFS, 0.71 for AI and 0.82 for FI, and 0.70 for the MDDI total score. Men and women showed differences in three subscales of the MDDI (DFS, AI, FI). McDonald's Omega showed an Al of (0 .72) DFS (0.72) FI (0.83) and total MDDI (0.82). Conclusion The MDDI-13 Arabic translation proved to be valid. Thus, the results are consistent with using the measure in Arabic-speaking nations. Level of evidence: Level V descriptive cross-sectional study.