Obesity dysmorphia as a psychiatric disorder: Simply fattening the DSM?

Facts about obesity are sobering. For example, in Australia, the prevalence of obesity among adults increased from 18.5% to 27.9% between 1995 and 2015 and is projected to continue increasing (Australian Bureau of Statistics, 2015). In 2005, the annual direct cost of obesity to the Australian economy was estimated at a staggering AUD$8.3 billion (Colagiuri et al., 2010). However, what is perhaps less widely appreciated, yet vital to informing the obesity debate, is the association of obesity with psychiatric distress and disability (Taylor et al., 2013). This works twofold in that certain maladaptive eating patterns lead to obesity and the obesity itself becomes a source of shame and disablement. Perhaps most pertinent here is binge eating disorder (BED), granted full diagnostic status in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). BED is characterised by episodic binge eating with the sense of loss of control over eating during the binge, but without the compensatory purging and other activities that are defining features of bulimia nervosa. BED has an episodic course and can be difficult to treat, albeit certain cognitive and behavioural strategies, and medications have shown promise in randomised controlled trials (Brownley et al., 2016). The other side of the obesity–mental illness association is the psychiatric distress and disability that are seemingly ‘secondary’ to the obesity itself; self-stigma, depression, social anxiety and associated disability are all common among people living with obesity. Of interest is that for some people with obesity, the whole problem becomes so frustrating that they seem to ‘give up’ on attempts to lose weight. For most others, the lure of magical diets and weight-loss formulations (including medications) is omnipresent and often indulged, unfortunately often without sustained weight loss. Thus, recognition of these psychosocial co-morbidities – and treatment thereof – is important for trying to help people with obesity enjoy a full life.

Larkin et al. (2017) have proposed ‘obesity dysmorphia’ (OD) as a new psychiatric condition, in part, to facilitate the recognition and treatment of these co-morbidities. The authors accurately state that some people with obesity experience significant body dissatisfaction and that the dietary, medical and surgical ‘cures’ they seek can be construed as maladaptive, reinforcing compulsive activities. Problems arise, however, in the authors’ use of body dysmorphic disorder (BDD) as a blueprint for OD. A key criterion for BDD is body preoccupation, not body dissatisfaction; with the former relating to repetitive and intrusive thoughts about one’s appearance and the latter referring to negative emotional appraisals (Mitchison et al., 2017). Furthermore, this preoccupation must be oriented towards a defect or flaw in appearance that – objectively – is either slight or non-existent. For some individuals who are obese, the subjective assessment of their body size will exceed objective appraisals, and thus, a diagnosis of BDD becomes viable. For others, the assessment of body size will be commensurate with reality. At this point, BDD is no longer a viable possibility and the resulting psychiatric distress and disability are secondary to the obesity itself. Putting aside the distinction between body dissatisfaction and preoccupation, it appears that Larkin et al. (2017) have positioned OD as a viable diagnosis for obese individuals with congruent subjective and objective assessments of their body size.

Larkin et al. (2017) do not mention, however, that the DSM-5 already accommodates individuals who are (1) obese, (2) experience clinically significant distress and impairment around their body size/weight and (3) report appraisals of their body size that are commensurate with reality. Specifically, individuals who report clinically distressing and/or impairing preoccupation with appearance flaws that are easily noticeable or clearly visible, as is the case for individuals who are obese, can be diagnosed with ‘other specified obsessive-compulsive and related disorder’ (OSOCRD). The key question for Larkin et al. (2017), is whether ‘OD’ should be demarcated from the catch-all category of OSOCRD. Furthermore, in answering this question, there must be consideration of BED, whose parent category of feeding and eating disorders is an exclusion criterion for a diagnosis of BDD.

Recognition and treatment of individuals who are obese and suffer from the numerous psychosocial co-morbidities associated with obesity is both admirable and needed. However, our understanding of Larkin et al.’s (2017) proposal is that it requires a more thorough examination of whether BDD is an appropriate blueprint for their new OD disorder. Furthermore, as part of this examination, much consideration should be given to BED. In the absence of this examination, we believe it is premature to expand the DSM with a new category of OD.

See Debate by Larkin et al., 51: 1085–1086