Walden University College of Social and Behavioral Sciences This is to certify that the doctoral dissertation by Sylvania Ann Jones has been found to be complete and satisfactory in all respects, and that any and all revisions required by the review committee have been made. Review Committee Dr. Anthony Perry, Committee Chairperson, Psychology Faculty Dr. Stephen Burgess, Committee Member, Psychology Faculty Dr. James Carroll, University Reviewer, Psychology Faculty Chief Academic Officer Eric Riedel, Ph.D. Walden University 2017 Factors Related to Muscle Dysmorphia Symptomology in Adolescent Males by Sylvania Ann Jones BS, Wayland Baptist University 1999 MA, Wayland Baptist University 2009 MA, Webster University 2006 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Psychology Walden University December 2016 The prevalence of muscle dysmorphia symptomology in adolescent males continues to increase, and yet remains under diagnosed in adolescents, supporting the need for a study to increase the understanding of the factors related to muscle dysmorphia symptomology. The purpose of this quantitative survey research study was to determine variables that predict the muscle dysmorphia symptomology in a nonclinical sample of high school adolescent males. The psycho-behavioral model of muscle dysmorphia was used as the conceptual model to explain the psychological factors such as self-esteem and body dissatisfaction and behavioral factors such as bodybuilding dependence that were hypothesized to be related to muscle dysmorphia. Quantitative surveys included the Body Dysmorphic Examination Self Report, Body Esteem Scale for Adolescents and Adults, Rosenberg Self-Esteem Scale, Body Building Dependence Scale and a researcher-developed demographic survey. The study participants included a sample of 97 high school males. Multiple regression analysis was used to determine the relative strength of the variables in predicting muscle dysmorphia. The results showed that there were several significant predictors of muscle dysmorphia symptomology including race/ethnicity, level of body dissatisfaction, and body building dependence. Sexual orientation and self-esteem were not significant predictors of muscle symptomology. The current study filled the gap in the literature regarding factors that predict muscle dysmorphia among adolescent males. This information supports the development of professional practice and psychoeducational programs designed to assist adolescent males with muscle dysmorphia. This study benefits this cohort by presenting awareness of muscle dysmorphia.