Obsessive-compulsive disorder (OCD) is one of the most frequently diagnosed psychiatric disorders in people with eating disorders. It is known to make eating disorders more severe and harder to treat, leading to a longer time until remission is achieved. Recently, more and more researchers are beginning to recognize the significance of the overlap between EDs and OCD, and are trying to develop specific treatments targeted at this population.
A 2004 study by Walter Kaye and colleagues in the American Journal of Psychiatry measured how frequently anxiety disorders (OCD is a type of anxiety disorder) occurred in people with anorexia and bulimia. They found that two-thirds of the ED sufferers had been diagnosed with an anxiety disorder at some point in their life. In general, the onset of the anxiety disorder pre-dated the ED by several years. Of the people with an anxiety disorder, 41% had OCD and 20% had social phobia (social anxiety). The problem, then, is very significant.
The gold standard in treating OCD is a form of cognitive-behavioral therapy known as exposure and response prevention (ERP). You can read more about ERP here . The idea is relatively straightforward: You create a hierarchy of the things you're afraid of that would normally provoke a compulsion. For someone who is afraid of germs, something lower on the list would be touching an unused surgical mask. Higher up might be touching a doorknob at a doctor's office or being coughed on by someone with a cold. Together with a therapist, you would begin to expose yourself to these anxiety-provoking situations and then not engage in any compulsions (like hand-washing) to relieve the anxiety. The point of this is to learn to tolerate the anxiety and that you're not going to die if you happen to inhale a few germs.
Some researchers are beginning to use components of ERP to treat food fears in EDs, especially anorexia nervosa. In a 2011 study in the International Journal of Eating Disorders, researchers at Columbia University first outline a behavioral model for AN that is driven by anxiety and obsessionality (see figure below; the caption is copied from the paper).
Figure 1. Model of Anorexia Nervosa. Traits of high baseline anxiety and obsessionality interact with environmental factors such that patients develop maladaptive behaviors, including food avoidance, and rigid eating patterns (or dieting practices), and they experience high levels of anxiety around eating. These behaviors are interrelated in that rigid dieting leads to increased anxiety about food and vice versa. These behaviors result in a diet that is low fat (low energy density) and limited in variety. This, in turn, promotes weight loss. The low weight state feeds back on the baseline traits and leads to increased levels of anxiety and obsessionality.
Anxiety about eating more and gaining weight consistently interferes with weight gain in AN and with interrupting the binge/purge cycle in BN. The idea is that recovery cannot and will not occur unless these fears are addressed. In a 2012 review article in the European Eating Disorders Review, psychologists hypothesize that one of the reasons family-based treatment is successful for many adolescents is that it forces these exposures. Since the patients can't (theoretically) choose what to eat, they can't choose to avoid "scary" foods. Parents are also coached on how to help stop other food-related rituals
A study published earlier this week addressed the issue of treating OCD and EDs, this time in a residential setting. Published in Cognitive Behaviour Therapy, the researchers treated 56 individuals with AN, BN, or EDNOS in an eating disorder program specific for individuals with co-occurring OCD. Of these patients, 41% were diagnosed with AN, 25% with BN, and 34% with EDNOS. Rates and levels of depression and OCD did not appear to vary by diagnosis. After treatment, the researchers found a significant improvement on scores for OCD, depression, and eating disorders, as assessed by a variety of surveys and self-reports. Patients with AN also significantly increased their body weight.
Which is all well and good, but the problem is that this study (nor any others that I'm aware of) compared the treatment group to anything. Other studies have shown that treating an ED generally improves levels of depression and OCD. Was the improvement seen in this study due to regular eating and the prevention of binge eating and purging? What effect did being in a structured environment have? Would these results have been different if the patients weren't treated for OCD? What about if their OCD was treated and not their ED? I realize that actually conducting a research study in that last scenario would be unethical, especially in a group that qualifies for residential treatment, but it's something that should at least be considered in the discussion.
Another question the researchers didn't factor in was the use of psychotropic medication. Eighty-nine percent of patients were on some type of psychiatric medication; the authors said they didn't control for this in their analysis since only 7% started on medication during their treatment. But they didn't mention how many patients' medication was adjusted, increasing or decreasing dose, or changing types and brands of medication. These things can have a significant effect on OCD and depression symptoms (although a recent study indicated that no psychotropic medications appear to be effective for AN)
As well, one of the researchers is the medical director of the treatment center where the research was carried out. This makes me a little skeptical of the results as a matter of course.
The researchers concluded that "Simultaneous treatment of OCD and eating disorders using a multimodal approach that emphasizes ERP techniques for both OCD and eating disorders can be an effective treatment strategy for these complex cases." But how effective? Is it better? How much better? How long did the results last for? There was no follow-up on any of these patients. Improving in a program is great, but the rubber doesn't really hit the road until after discharge.
This study is a start, but it's a small start. Co-occurring EDs and OCD can be very difficult to treat, but many people do go on to develop healthy and productive lives. We desperately need more resarch into the subject, but we need to start making comparisons to help develop the best, most effective treatment possible.