Roughly 11 percent to 13 percent of people who receive a diagnosis for obsessive-compulsive disorder (OCD) also meet the diagnostic criteria for an eating disorder such as anorexia nervosa, bulimia nervosa or binge-eating disorder. According to the results of a study published in 2013 in the journal Cognitive Behavior Therapy, people simultaneously affected by an eating disorder and OCD receive significant benefit from treatment with a form of psychotherapy called exposure and response prevention or ERP. ERP belongs to a larger group of psychotherapeutic techniques collectively labeled as cognitive behavioral therapy. Eating Disorders and OCD Eating disorders can develop independently in people affected by obsessive-compulsive disorder. However, they also sometimes occur as a direct consequence of the presence of OCD. Eating disorders that stem from OCD typically begin when an OCD-related obsession or compulsion interferes with the act of regular food consumption. For instance, a person obsessed with choking on his or her food might start putting anorexia-like restrictions on food consumption to reduce any perceived choking risks. Conversely, the presence of the body- and weight-related obsessions classically associated with eating disorders can lead to the development of elaborate eating rituals that closely mimic the behavioral urges (i.e., compulsions) found in people with OCD. In cases where OCD and an eating disorder appear together, doctors often need to give considerable effort to determining which symptoms belong to which disorder. In some circumstances, the symptoms in a single individual are so intertwined that their placement as OCD-related or eating disorder-related problems is largely subjective. However, most people have telltale details in their symptoms that give clear support to one diagnosis or the other. Cognitive Behavioral Therapy and ERP Cognitive behavioral therapy (CBT) is a general term used to describe any form of psychotherapy that seeks to make participants consciously aware of the psychological reactions that negatively affect their lives, and also uses this newfound awareness to teach participants how to learn new behaviors that reduce negative outcomes and produce more positive or beneficial results. Apart from exposure and response prevention, therapeutic approaches that fall under the CBT heading include dialectical behavior therapy, rational emotive behavior therapy, cognitive therapy and rational living therapy. Exposure and response prevention is widely considered to be the most effective form of cognitive behavioral therapy for the treatment of obsessive-compulsive disorder. The treatment gets its name because participants are purposefully exposed to situations or circumstances that trigger their OCD-related behaviors, then taught how to prevent themselves from responding to those situations and circumstances in their habitual ways. This approach may seem counterintuitive, since a failure to resist compulsive urges in high-stress settings is an essential component of OCD. However, through exposure to the very settings they fear the most, ERP participants can gain a unique sense of mastery over their obsessions and compulsions. Simultaneous Treatment In the study published in Cognitive Behavior Therapy, a team of researchers from Columbia University examined the effects of exposure and response prevention in 56 patients diagnosed with both obsessive-compulsive disorder and an eating disorder. In addition to the normal ERP approach developed for OCD treatment, the participants received ERP specifically designed to address their eating disorder-related symptoms. After a period of roughly two months, the study participants experienced significant decreases in the intensity of their OCD symptoms, as well as significant decreases in the intensity of their eating disorder-related symptoms. While anorexia patients and bulimia patients all saw some improvement, the greatest improvements occurred in individuals with bulimia. Patients enrolled in the study who had depression-related symptoms also experienced a decline in the intensity of those symptoms. Considerations In addition to ERP treatments geared specifically toward eating disorders and ERP treatments geared specifically toward OCD, participants in the Columbia University study also received psychiatric medications, took part in structured eating programs and participated in group support sessions. However, the authors of the study view simultaneous ERP treatment as the key factor in producing positive outcomes in the study\u2019s participants. Because of its reliance on direct confrontation of symptom-triggering situations, ERP is commonly viewed as an especially rigorous form of cognitive behavioral therapy. Despite its positive results, some people with OCD and\/or an eating disorder may have difficulty completing a course of ERP therapy without considerable secondary care and support.