Muscle dysmorphia: Towards a diagnostic consensus

With the impending release of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), much research is currently being directed at refining the categorisation and diagnostic guidelines for eating disorders, given that up to 60% of eating disorder cases currently fall into the residual Eating Disorder Not Otherwise Specified (EDNOS) category (Fairburn et al., 2007). Research has now called for those developing the DSM-5 to ‘recast the diagnostic scheme in such a way that it accurately represents clinical reality and is of value to clinicians’ (Fairburn and Cooper, 2011: 8). This is particularly pertinent for males, given that ‘there is not an eating disorder diagnosis specifically geared towards the male experience of eating disorder pathology’ (Greenberg and Schoen, 2008: 469), despite empirical evidence documenting that body image dissatisfaction and eating disorder psychopathology in both indigenous and non-indigenous Australian males are increasingly oriented towards the acquisition of muscularity rather than the reduction of body adiposity (Darcy et al., 2012; Mellor et al., 2004; Murray et al., 2012).

Muscle dysmorphia represents the pathological pursuit of muscularity and is characterised by an intensely distressing preoccupation that one is of insufficient muscularity (despite, in many cases, having well-developed muscles) coupled with rigorous exercise and dietary practices that take precedence over other important areas of life. Currently, muscle dysmorphia is characterised by a lack of nosological clarity, with proponents demonstrating widespread similarities to eating disorders, although this illness is currently conceptualised as a body dysmorphic disorder subtype (Pope et al., 1997). However, the phenomenology of muscle dysmorphia displays marked differences to the documented features of body dysmorphic disorder. For example, presentations of body dysmorphic disorder do not generally include food- and exercise-related psychopathology, and the diagnostic criteria for body dysmorphic disorder posit that those experiencing such concerns, in conjunction with shape-related body image and weight distortion, are best accounted for by an eating disorder diagnosis. In addition, muscle dysmorphia typically presents inclusive of greater and more widespread psychopathology and functional impairment in comparison to body dysmorphic disorder (Pope et al., 2005), demonstrating similar levels to eating disorders.

Muscle dysmorphia has therefore been reanalysed through the lens of an eating disorder spectrum, which may reportedly help delineate meaningful subcategories from the EDNOS spectrum. Muscle dysmorphia displays similar epidemiological features to eating disorders, with reported prevalence rates commensurate with anorexia nervosa in women, and also features a heavily polarised gender prevalence, which is largely disparate to the epidemiology of body dysmorphic disorder (Murray et al., 2010), and responds well to eating disorder treatment programs (Greenberg and Schoen, 2008). In addition, emerging research suggests that muscle dysmorphia is inclusive of central eating- and exercise-related practices, such that eating practices alone exacerbate symptomatology (Murray et al., 2011), and that the exercise practices endorsed serve similar psychological and physiological functions to those reported in anorexia nervosa (Murray et al., 2012).

Muscle dysmorphia may arguably be nosologically similar to eating disorders, comprising similar profiles of eating- and exercise-related pathology, suggesting that the primary difference between the disorders may be the directionality of symptomatology. Muscle dysmorphia is oriented towards the acquisition of body mass, whereas anorexia nervosa is oriented towards the shedding of body mass, and in this sense the two disorders are antonymic. However, such antonymic presentations in the directionality of body ideals would make both disorders consistent with the sociocultural body ideals portrayed to men and women respectively. The majority of men experiencing body dissatisfaction reportedly desire a more muscular physique (McCreary and Sasse, 2000), whereas the majority of body dissatisfied women desire a thinner physical build (Betz et al., 1994), which is indeed reflected in the prevalence of muscle dysmorphia in men (Grieve, 2007) and anorexia nervosa in women (Carlat et al., 1997) respectively. Thus, both disorders may represent the pathological pursuit of the culturally shaped antonymic body ideals for men and women respectively (which partially accounts for the skew in gender prevalence of each disorder). This is consistent with findings demonstrating that elevated masculinity and femininity may constitute risk factors into a causal pathway for both disorders respectively (Pope et al., 2000; Pritchard, 2008).

This emerging evidence suggests that muscle dysmorphia may represent an alternative eating disorder phenotype, which if further validated, may have significant ramifications for how our current diagnostic scheme is recast and help account for the male experience of eating disorder psychopathology (Greenberg and Schoen, 2008). Further, this would likely aid ongoing attempts to delineate meaningful subcategories from the current majority of cases falling into the EDNOS category, which has been identified as a key task for those redeveloping the diagnostic classification scheme (Fairburn and Cooper, 2011).