In DSM-5 the diagnosis of body dysmorphic disorder (BDD) has been subjected to two important changes: Firstly, BDD has been assigned to the category of obsessive–compulsive and related disorders. Secondly, a new criterion has been defined requiring the presence of repetitive behaviors or mental acts in response to appearance concerns. The aims of this study were to report the prevalence rates of BDD based on a DSM-5 diagnosis, and to evaluate the impact of the recently introduced DSM-5 criteria for BDD by comparing the prevalence rates (DSM-5 vs. DSM-IV).
Body dysmorphic disorder (BDD) is characterized by a severe preoccupation with a defect in physical appearance that is objectively slight or may even be unobservable, resulting in distress and impairment in social and/or occupational functioning [1]. Two epidemiological surveys among the German general population revealed a point prevalence of 1.7–1.8% [2] and [3], and a prevalence rate of 2.4% was found among the general population of the United States of America [4].
BDD was first included in DSM-III as an example of an atypical somatoform disorder called “dysmorphophobia” [5]. In the course of subsequent DSM-editions, BDD was classified in the somatoform section as a self-contained disorder. In DSM-IV (and DSM-IV-TR) the BDD diagnosis was based on three criteria [6] and [7]: preoccupation with appearance, distress and impairment, and appearance concerns that are not better accounted for by any other mental disorder. The recently published DSM-5 has experienced two important changes concerning the classification of BDD [8]: a relocation of the diagnosis and an extension of the diagnostic criteria. In DSM-5, BDD is now classified under the new category “obsessive–compulsive and related disorders”, along with obsessive–compulsive disorder, trichotillomania, hoarding disorder, and excoriation disorder. In addition, a new criterion has been defined requiring that “at some point during the course of the disorder, the person has performed repetitive behaviors (e.g., mirror checking, excessive grooming, skin picking, reassurance seeking), or mental acts (e.g., comparing his or her appearance with that of others) in response to the appearance concerns” (p. 242, DSM-5 [8]). Furthermore, a specifier for muscle dysmorphia was added as well as a specifier that indicates the degree of insight regarding BDD beliefs. Apart from that, some minor revisions have been made such as more precise phrasing and changes in the wording.
The classification of BDD as a somatoform disorder has often been questioned and similarities between BDD and obsessive–compulsive disorder, social phobia, eating disorders, and affective disorders, have been discussed. Most research has focused on the relationship between BDD and obsessive–compulsive disorder, with empirical evidence underpinning the inclusion of BDD among the obsessive–compulsive and related disorders [9], [10], [11], [12] and [13]. The high comorbidity between BDD and obsessive–compulsive disorder [10], [14] and [15] as well as similar characteristics [16] and [17] such as repetitive thoughts and behaviors, an early onset and a chronic course of the disease [18] and [19], shared genetic factors [20], and neurobiological features [21] and [22], indicate that BDD and obsessive–compulsive disorder are related disorders. Because of these similarities, classification of BDD among the obsessive–compulsive and related disorders has been widely supported [9]. Nonetheless, BDD and obsessive–compulsive disorder represent distinct disorders [23], [24] and [25] and therefore merit independent diagnoses.
The new DSM-5 criterion for a BDD diagnosis, which requires the presence of repetitive behaviors or mental acts (at some point during the course of the disorder), reflects the likely relatedness of BDD to obsessive–compulsive and related disorders [11] and may help to differentiate BDD from other disorders such as major depression or social phobia [11]. Furthermore, repetitive behaviors and thoughts are considered to be key aspects of the clinical picture of BDD. For example, grooming, camouflaging, and mirror checking, are common acts [15] performed by individuals with BDD, with the aim to correct, hide, or distract from perceived defective body parts. Focusing on unattractive body parts, rumination, mental rituals or other mental acts are also often reported by individuals with BDD [15] and [26]. They suffer from these symptoms as they are time-consuming and can last several hours or the entire day [27]. However, BDD prevalence has not yet been established using the newly added criterion requiring repetitive behaviors and cognitive processes.
Some diagnostic concepts and assessment procedures [2], [28] and [29] suggested the use of a time-criterion to differ between degrees of BDD severity. The Structured Clinical Interview for DSM-IV [29] adds a time-requirement to BDD criterion A and specifies that preoccupation with appearance should last for at least one hour/day. The same procedure was used in a German general population survey [2]. However, the Yale-Brown Obsessive–Compulsive Scale, modified for BDD [28], proposed degrees of severity based on the average time an individual is occupied with thoughts as well as behaviors regarding appearance concerns. A proposal for BDD severity was also made during the DSM-5 development process (www.dsm5.org update nov-8-2010) including the daily amount of time spent on concerns and repetitive behaviors related to physical appearance.
The advantage of the new DSM-5 criteria is that repetitive behaviors or mental acts, with respect to appearance concerns, are now considered to be a characteristic of BDD. Thus, the clinical picture of BDD is better defined. However, the new criteria do not appear to considerably affect the BDD case identification. Our findings show that almost the same BDD cases were identified using DSM-IV criteria, as were identified using DSM-5 criteria. Nevertheless, the newly specified criterion B may be useful to distinguish between various degrees of severity of BDD, e.g. considering the amount of time spent on repetitive behaviors.
