Is anorexia nervosa a subtype of body dysmorphic disorder (BDD)? Well, probably not, but don’t click the close button just yet. In this post, I’ll explore the relationship between anorexia nervosa and BDD, and discuss how understanding this relationship might help us develop better treatments for both disorders.
Despite the fact that there are obvious similarities between the disorders, studies exploring the relationship between BDD and AN are few and far between. In a recent paper, published in the Clinical Psychology Review, Andrea Hartmann and colleagues summarized the current state of knowledge in the field. The review compared clinical, personality, demographic, and treatment outcome features of AN and BDD. I’ll summarize the key points of the paper in this post.
(I will be focusing on the relationship between AN and BDD, as opposed to EDs and BDD, because that’s the scope of the review article.)
First, what is body dysmorphic disorder?
[BDD] is defined as distressing or impairing preoccupation with an imagined[/perceived] or slight defect in physical appearance. If a slight physical anomaly is present, the preoccupation is markedly excessive (APA, 2000). Most patients with BDD engage in compulsive behaviors to examine, hide, or improve the perceived defect (Phillips, McElroy, Keck, Pope, & Hudson, 1993; Phillips, Menard, Fay, & Pagano, 2005a) [...]. Appearance-related preoccupations and compulsions are time consuming and cause clinically significant distress and/or impairment in social, occupational, or other important areas of functioning (APA, 2000).
Approximately 1/3 of individuals do NOT recognize that the beliefs about their appearance are due to a mental disorder and 2/3 believe that other people are laughing/staring at them because of their defects. The DSM-5 includes (I was going to write “will include” but it is already out now) an insight specifier which is meant to capture the range of insight that patients with BDD may have about their disorder. Unfortunately, an insight specifier is not included in the DSM-5 for eating disorder diagnoses.
(I’m going to assume that I do not need to include a definition of anorexia nervosa for this audience?)
So, what are the similarities between BDD and AN? I’ve tried to summarize the salient points of the review below, but feel free to ask questions or request clarifications in the comments section if something is unclear.
DIAGNOSTIC OVERLAP BETWEEN AN and BDD
Onset, demographic characteristics, and illness course:
ONSET: Similar, usually in the mid-teens
- Similar rates, around 0.5-2%, although BDD seems to be more prevalent than AN
- AN is more prevalent in females whereas the frequency of BDD is only slightly higher among females
- Just as with AN, however, there are differences in how males and females present with their symptoms (i.e., the concerns they have tend to differ)
COURSE OF ILLNESS: Both seem to be long-lasting disorders for a large proportion of the patients, although BDD appears to be chronic for a larger portion of those diagnosed than AN (That said, there are so many biases that come into play when evaluating long-term outcomes that it is really hard to say.)
The authors point to other differences among AN and BDD patients (in socioeconomic status, educational attainment, prevalence among different ethnic groups, likelihood of being in a relationship, etc.) but, to be quite honest, I don’t trust the data because there are so many things affecting who seeks treatment and participants in studies that one or two studies suggesting a difference are hardly sufficient.
COMORBIDITY WITH OTHER DISORDERS:
- AN is highly comorbid with depression, anxiety disorders (including OCD), and substance abuse
- BDD is commonly diagnosed with depression, social anxiety disorder, OCD, and substance abuse
- Both are comorbid with “Cluster C” personality disorders: avoidant, dependent, and obsessive-compulsive
COMORBIDITY WITH EACH OTHER:
- It is hard to say. The studies cited in the review are tiny. One found that 25% of females between the ages of 12-21 had showed symptoms of BDD, whereas 0% of females with bulimia nervosa had. Sample size: 36 inpatients with AN and 17 with BN. In another study of 41 AN inpatients, 39% had lifetime BDD diagnoses.
- On the other hand, 9% of BDD patients had lifetime AN diagnoses. In cases with comorbid BDD and AN, BDD seems to precede AN. Unsurprisingly, those with dual diagnoses fared worse than those with just one.
BODY IMAGE DISTURBANCES & ATTRACTIVENESS BELIEFS:
- Individuals with AN and BDD both have body image disturbances (and these are more pronounced in those suffering from both AN and BDD). Patients with AN focus on weight/shape, whereas patients with BDD can have weight and shape related concerns but tend to focus on other parts of the body such as skin, hair, and nose.
- Individuals with AN and BDD tend to have appearance-related behaviours, such as body checking, and tend to avoid places/activities where they might feel more self-conscious because of their appearance (like the beach, for example).
- Some studies suggest that body image disturbances are more serious in BDD than AN, and that patients with BDD tend to overestimate the importance of their appearance and invest more time in it. (This is not surprising, I feel.)
- Individuals with BDD and AN tend to associate attractiveness and appearance with things like competence, achievement, and performance more than healthy controls, but it is hard to say how the disorders compare to each other.
Both BDD and AN patients tend to:
- be detail-oriented (as opposed to globally oriented) and “miss the forest for the trees”
- be more likely to interpret neutral or ambiguous social or appearance-related situations as being negative
- have difficulties with emotional processing, particularly emotion recognition and emotion regulation
- have difficulties with executive function (like decision-making and set-shifting), but more studies have been done in AN than BDD
SUICIDALITY: Suicide attempts and suicidal ideation are high in both BDD and AN, and again, having comorbid BDD and AN seems to increase the rate of attempted suicides.
DELUSIONALITY: Around 1/5 – 1/4 of those with AN seem to have very poor insight into their eating disorder. (Though, there’s a question of whether it is a lack of awareness/poor insight or deliberate denial?) As mentioned previously, about 1/3 of patients with BDD seem to have very poor insight about their disorder.
PERSONALITY CHARACTERISTICS: Both BDD and AN patients have higher perfectionism, neuroticism, negative emotionality, and harm avoidance traits, as well as low novelty seeking and self-directedness than healthy controls. However, to my knowledge, no studies have compared BDD to AN directly.
Clearly, there are many similarities between AN and BDD. But when it comes to effective treatment modalities , the similarities fade:
While there is only evidence for SSRIs in AN for relapse prevention after weight restoration*, for BDD, pharmacotherapy with (S)SRIs (and potentially an augmentation with atypical neuroleptics as a secondary treatment strategy) has proven to be successful. In terms of psychological treatment, only family therapy is successful in adolescents with AN (my post on FBT); there is limited evidence for other treatments so far, with an enhanced form of CBT and UCAN showing initial promising results [I'm not sure why the authors decided to focus on CBT (I blogged about a not-so-good CBT study here) and UCAN (Check out my post about UCAN here)... I am really puzzled by this]. In BDD, CBT has proven to be successful in adults in several small studies, and there is preliminary support of this treatment in adolescence.
*I just want to mention that, although this is anecdotal and I have not looked at the literature myself, but I found that an SSRI (sertraline) was VERY effective for reducing general anxiety for me at a low weight (BMI 15), and anecdotally, I know many others who found SSRIs effective for anxiety at low BMIs, so, I’m not convinced that it is ineffective at a low weight. It was much more effective than I expected it to be (I was VERY, VERY skeptical).
Anyway, getting back to the paper. The final part of the review was a discussion about what can we learn from AN treatment that can be utilized in BDD and vice-versa. I think there were some good points made here.
What can we learn from AN treatment that we can potentially utilize in treating BDD? Well, involving parents (as in family-based treatment) or partners (as in UCAN) might be helpful. After all, “a combination of communication skills, exchange of conceptualizations of the disorder, and planning for more appropriate dealing with the disorder in particular difficult situations might improve the inclusion of spouses and partners [and family] in the treatment of BDD.”
What can we learn from BDD treatment that we can incorporate into AN treatment? Mindfulness training, which is popular in BDD treatment, is something that can be incorporated into treatment. (Although, I’m sure lots of therapists and clinicians do this.) Emotion recognition training is another tool we might be able to add to AN treatment. (Though, again, I’m sure this is something a lot of therapists incorporate into their practice.) It will be important to decipher whether, and to what extent, these are beneficial (and for what subgroups of patients) and, if they are, what the best way to deliver training. Finally, exposure and ritual prevention training, which, according to the authors is a hallmark of CBT treatment for BDD, might be helpful for AN. Indeed, a recent preliminary study suggests that food exposure might be helpful in treating AN (see Steinglass et al., 2012).
To conclude, this review highlights some of the similarities between AN and BDD. But (there’s always a but) there’s still more work to be done when it comes to understanding the relationship between AN and BDD (and EDs and BDD in general). Namely, we need more studies directly comparing AN-only, BDD-only, AN+BDD, and healthy controls. Moreover, whether these similarities are reflective of the same underlying causal factors remains to be determined. (This is probably the question that interests me the most.) Finally, although successful treatment modalities for AN and BDD differ, there does appear to be a lot of room for incorporating successful treatment approaches for one disorder to the other. Why not try, anyway?
Readers, what are your thoughts? I’m particularly curious to hear from those who have struggled with BDD and/or BDD and an ED, as well as clinicians who treat either one or both. Do you agree or disagree with any points made in this post? How do your experiences compare with what’s been highlighted by the studies?