Mind over Muscles: Testing the Impacts of Psychological Avoidance on Changes in Muscle Dysmorphia Symptoms over Time for Men Enrolled in a Body Acceptance Program

Abstract

Men with muscle dysmorphia (MD) engage in harmful behaviors to conform to a muscular ideal, often driven by psychological avoidance of body-related distress. While dissonance-based (DB) interventions effectively reduce MD symptoms, the impact of psychological avoidance on intervention effects remains unexplored. This study examined whether baseline psychological avoidance moderates MD symptom changes in a body acceptance program. Participants (N=200) were randomized to a DB intervention or active control condition, completing the Muscle Dysmorphic Disorder Inventory (MMDI) and Acceptance and Action Questionnaire (AAQ-II) at four timepoints (baseline, post-intervention, one-month, six-month follow-ups). AAQ-II scores were associated with MMDI subscales across time, with small to moderate effects. Multilevel modeling revealed significant symptom reductions over time but no significant interaction effects between psychological avoidance, condition, and time. Results suggest DB interventions effectively reduce MD symptoms, irrespective of psychological avoidance, although avoidance may coincide with impairment in daily functioning.