Community norms of the Muscle Dysmorphic Disorder Inventory (MDDI) among gender minority populations

Purpose Representing the pathological extreme pursuit of muscularity, muscle dysmorphia (MD) is characterized by a pervasive belief or fear around insufficient muscularity and an elevated drive for muscularity. Despite evidence of heightened body image-related concerns among gender minority populations, little is known about the degree of MD symptoms among gender minorities, particularly based on Muscle Dysmorphic Disorder Inventory (MDDI) scores. The objective of this study was to assess community norms of the MDDI in gender-expansive people, transgender men, and transgender women. Method Data from participants in The PRIDE Study, an existing study of health outcomes in sexual and gender minority people, were examined. We calculated means, standard deviations, and percentiles for the MDDI total and subscale scores among gender-expansive people (i.e., those who identify outside of the binary system of man or woman; n = 1023), transgender men (n = 326), and transgender women (n = 177). The Kruskal-Wallis test was used to assess group differences and post hoc Dunn’s tests were used to examine pairwise differences. Results Transgender men reported the highest mean MDDI total score (30.5 ± 7.5), followed by gender-expansive people (27.2 ± 6.7), then transgender women (24.6 ± 5.7). The differences in total MDDI score were driven largely by the Drive for Size subscale and, to a lesser extent, the Functional Impairment subscale. There were no significant differences in the Appearance Intolerance subscale among the three groups. Conclusions Transgender men reported higher Drive for Size, Functional Impairment, and Total MDDI scores compared to gender-expansive people and transgender women. These norms provide insights into the experience of MD symptoms among gender minorities and can aid researchers and clinicians in the interpretation of MDDI scores among gender minority populations.
Plain English summary Transgender people have a gender identity or expression that differs from what is typically associated with the sex assigned to them at birth. Gender-expansive refers to gender identities that do not fit within the binary (woman/man) gender system. We asked gender-expansive people, transgender men, and transgender women in The PRIDE Study to fill out a widely used survey about muscle dysmorphia, a condition in which a person worries they are not muscular enough. The results showed that transgender men had the highest muscle dysmorphia symptoms, followed by gender-expansive people, then transgender women. These findings can help clinicians and researchers in interpreting a survey assessing muscle dysmorphia in gender-expansive people, transgender men, and transgender women. Characterizing muscle dysmorphia symptoms in these populations is an important step to improve mental wellness among transgender and gender-expansive people.