Publication Date


Advisor(s) - Committee Chair

Dr. Frederick Grieve (Director), Dr. Elisabeth Jones, Dr. Pitt Derryberry

Degree Program

Department of Psychology

Degree Type

Master of Arts


Throughout the years, women have been the focus of eating disorders and body image research. With women being the focus of research in these areas, disorders such as Anorexia Nervosa, Bulimia Nervosa, and Body Dysmorphic Disorder (BDD) have caught the eyes of researchers. With this new discovery, there has been a recent surge of research on body image issues and men. Originally termed reverse anorexia or bigorexia, Muscle Dysmorphia (MD) has gained the attention of researchers for about a decade (Grieve, 2007; Pope, Katz & Hudson, 1993; Pope, Gruber, Choi, Olivardia & Phillips, 1997).
The Muscle Dysmorphia Inventory (MDI) was created to measure the symptoms of MD and provide clinicians with an inventory that would aid them in the diagnosis and treatment of MD (Short, 2005). The MDI is a 34-item scale that uses the etiological model proposed by Grieve (2007) and assesses or evaluates the four proposed diagnostic criteria of MD (Short, 2005). Short (2005) developed questions using the four criteria of MD outlined by Olivardia (2001).
While the MDI has shown good internal consistency (Cronbach’s alpha = .87; Short, 2005), no other psychometric properties have been assessed. The goal of this study was to assess the validity and reliability of the MDI so that the accuracy of the measure will be known and it may be used as a diagnostic tool in clinical settings. The hypothesis of the study was that the MDI is a reliable and valid measure.
This study assessed the reliability and validity of the MDI through a correlational design. Test-retest reliability and Cronbach’s alpha were used to identify the reliability of the MDI. The MDI was compared to tests that measure traits of MD and to self-reported behaviors, which assessed concurrent and predictive validity of the MDI.
The MDI appears to be a good diagnostic tool for clinicians to use when looking at MD. This study examined the reliability and the validity of the MDI. This study shows that the MDI has adequate test-retest reliability, and good internal consistency. The results indicate that the MDI has good concurrent validity when compared to other tests that measure symptoms of MD. Under predictive validity, there was some support to suggest that the MDI can predict MD, however, the predictive validity of the MDI needs to be examined more in-depth. The MDI appears to measure more state symptoms of MD than trait symptoms. This may make it easier for clinicians to detect an emerging problem before it becomes harder for the individual to overcome.


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