Muscle dysmorphia symptomatology is prospectively associated with suicidal thoughts, suicidal behaviors, and non-suicidal self-injury among a sample of Canadian adolescents and young adults

Introduction Limited, primarily cross-sectional research has identified associations between muscle dysmorphia and suicidal thoughts suicidal behaviors, and non-suicidal self-injury (NSSI). This study aimed to investigate the associations between muscle dysmorphia and suicidal thoughts, suicidal behaviors, and NSSI prospectively over a 1-year period among a large, diverse sample of Canadian adolescents and young adults. Methods Data from wave one (2021) and wave two (2022) of the Canadian Study of Adolescent Health Behaviors were analyzed (N = 912). Multiple modified Poisson regression analyses were used to determine the associations between muscle dysmorphia symptomatology at wave one and three items of suicidal thoughts and behaviors and one item of NSSI at wave two. Unadjusted models and adjusted models were estimated. Results Total muscle dysmorphia symptomatology and symptoms of Appearance Intolerance were prospectively associated with suicidal ideation and suicide planning at 12-month follow-up. These findings were significant across unadjusted and adjusted models. Conclusions Findings from this study expand prior research and underscore the clinical complexity of muscle dysmorphia. Future research should investigate mechanisms explaining the association between muscle dysmorphia and suicide and develop interventions to prevent suicide among people with muscle dysmorphia.