Differential prevalence of depressive and narcissistic traits in competing and non-competing bodybuilders in relation to muscle dysmorphia levels

Background: Muscle dysmorphia is considered a subtype of body dysmorphic disorder with a high prevalence in bodybuilders. Observational and experimental data suggest a differential prevalence for depressive and narcissistic-like traits between people involved in competing or non-competing bodybuilding activity. Methods: Here we assessed symptoms related to muscle dysmorphia (Muscle Dysmorphic Disorder Inventory, MDDI), depression (Back Depression Inventory, BDI), and narcissism (Narcissistic Personality Inventory, NPI) (among others dimensions) in 260 subjects representing non-training subjects (controls), competing and non-competing bodybuilders. Given the large variability within the sample, a data-driven classification approach allowed excluding outliers as well competing/non-competing subjects not showing any clinically significant features, thereby restricting the analysis to a core group of subjects (n = 178). Results: Results showed a significant difference in depression and narcissism levels between competing and non-competing bodybuilders (NPI, F = 34.186, p < 0.01; BDI, F = 10.298, p < 0.05), with higher level of narcissism detected in the former ones, while a slight depressive symptomatology has been identified in the latter ones. Post-hoc comparisons (p < 0.05 Bonferroni corrected) showed significant differences between competing/non-competing subjects and controls. Conclusions: Our results suggest a potential interaction between muscle dysmorphic symptoms, narcissism and depression, with a stronger association between narcissistic traits and the development of more severe muscle dysmorphic conditions in competing bodybuilders.