Muscle dysmorphia: A systematic and meta-analytic review of the literature to assess diagnostic validity

Objective: Although muscle dysmorphia (MD) is a new addition to DSM-5 as a specifier of body dysmorphic disorder (BDD), previous studies have treated MD as a stand-alone diagnosis. We aimed to assess the validity of MD as a stand-alone diagnosis via systematic and meta-analytic review of MD literature using both Robins and Guze criteria and additional criteria from Kendler. Method: We performed a systematic search of ProQuest, PsycInfo, and PubMed databases for the period of January 1993 to October 2019 resulting in 40 papers to examine Robins and Guze's criteria (clinical picture) as well as those added by Kendler (antecedent validators; concurrent validators; predictive validators). Results: We identified two distinct symptomatic presentations of MD using cluster analysis, a behavioral type and cognitive/behavioral type. For examining the concurrent validators, quantitative meta-analyses differentiated MD populations from controls; however, results were inconclusive in delineating MD from existing disorders. For assessing antecedent and predictive validators, the symptomatic profiles, treatment response, and familial links for MD were similar to those for BDD and for eating disorders. Discussion: We found preliminary support for MD as a clinically valid presentation, but insufficient evidence to determine whether it is best categorized as a specifier of BDD or unique psychiatric condition.