This is a guest post by Jackie Shapin, a licensed Marriage and Family Therapist who specializes in anxiety, OCD, and eating disorders. 

Obsessive Compulsive Disorder (OCD) affects approximately one in 40 individuals worldwide. And while it has been ranked in the top 10 most disabling mental health conditions, what is less often understood is the interplay between the disorder and another group of mental health conditions that has some of the highest mortality rates of any: eating disorders. 

On the surface, OCD and eating disorders might seem very different, but both of these diagnoses can cause life-altering impairments in a person’s ability to function. What’s more, their symptoms can mirror, underpin, and reinforce each other. Let’s look further into the relationship between OCD and eating disorders.

How eating disorders and OCD can go hand in hand

Research has demonstrated that more than 40 percent of people with an eating disorder may also experience symptoms of OCD and as many as 17 percent of people who have OCD may also have an eating disorder. 

OCD is a mental illness that is characterized by obsessions and compulsions. Obsessions are unwanted intrusive thoughts, feelings, images, or ideas that create anxiety or distress. Compulsions are the acts a person performs to reduce this anxiety and distress or prevent a feared outcome, and they can come in many forms. They can be physical behaviors or rituals, or they can involve mental behaviors and cyclical thought patterns. No matter what form they take, compulsions make obsessions and the resulting distress worse and worse over time, trapping people in a cycle that only provides temporary relief until it strikes again.

This same cycle exists among eating disorders, a category including Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder, Avoidant/Restrictive Food Intake Disorder (ARFID), and a range of other disorders without specific categorization. While these disorders have many significant differences, they all include some preoccupation with the body and/or food. These thoughts, beliefs, ideas, and feelings about one’s food and body can be intrusive, unwanted, and highly distressing—quite like obsessions in OCD.

Furthermore, the behaviors that people with eating disorders perform in response to these thoughts, such as excessive exercise, food restriction, calorie counting, binging, purging, laxative use, and rumination are quite similar to compulsions in OCD. And there are further similarities between eating disorders and OCD, as well. For example, both diagnoses involve intrusive thoughts. Everyone has intrusive thoughts from time to time, but people with these disorders tend to get “stuck” on them and over-value them, and they experience significant distress or anxiety as a result. 

Let’s look at some of the similarities between the experiences of people with OCD and those with eating disorders. For example, someone with an eating disorder may use obsessive exercise as a means to burn off calories or in an attempt to change their physical appearance. Someone with OCD might show similar behavior, with exercise used instead to reduce fear of health risks or in a way that is related to magical thinking: “Something bad will happen if I don’t exercise.” OCD and eating disorders can both be extremely time consuming, can negatively impact one’s physical health, can be associated with trauma, can relate to a dependency on the external world for trust and safety, and often involve rigidity, perfectionism, magical thinking, shame and guilt, and hyper-responsibility.

While scientists are just beginning to understand these connections, preliminary research suggests similarities in how the brains of people with OCD and eating disorders process information. A 2004 study led by researchers at the Clinic for Psychosomatic Medicine in Germany, for example, found similarities in how patients with OCD and patients with anorexia responded to a task involving the prefrontal cortex and caudate nucleus, the parts of the brain involved with things like planning complex behaviors, learning, emotion, and more. Their brains also showed elevated cerebral glucose metabolism, which, explains the researchers, offers evidence that both diagnoses could have origins in common neurobiological abnormalities. Other brain imaging shows similar findings in people with OCD. More research is needed to find out if this, or other, abnormalities associated with OCD are also present in people with eating disorders.

The key differences between OCD and eating disorders

While striking similarities exist, the differences between OCD and eating disorders can make a significant impact on how they are treated. 

Intrusive thoughts can be easier to identify in OCD because they are usually distressing and conflict with a person or culture’s values. People that have OCD do not like their thoughts and have a lot of fear associated with them. Identifying this characteristic, known by professionals as ego-dystonic, is a critical part of diagnosing OCD. What makes intrusive thoughts particularly nefarious in eating disorders is that many of them are reinforced by culture, which means that people with an eating disorder do not always view these thoughts and behaviors as problematic. 

Because eating disorders are not always ego-dystonic, motivation for change is often more difficult than it is among OCD sufferers. Most obsessions and accompanying compulsions related to OCD are irrational, whereas eating disorder behaviors may be somewhat rational at times. Obsessive thoughts around the body, or the belief that certain foods are “good” or “bad” often align with and are reinforced by the beliefs of culture as a whole. What is often irrational is the amount of distress a person is in because of their eating disorder beliefs.

These differences must be taken into account when we think about treating OCD and eating disorders. It is crucial for a clinician to more closely examine not only specific behaviors observed but also the motivations behind those behaviors. Asking “why?” can help untangle the web between OCD and eating disorder symptoms. Asking questions such as, “Why are your obsessions distressing? What is driving you to perform compulsions? What is the feared outcome?” This will most likely distinguish whether someone has OCD or an eating disorder.

Despite having many similarities, OCD and eating disorders are often treated differently and it is important to know what modalities are best for each. Active behavioral therapy modalities like Cognitive Behavioral Therapy (CBT) may be helpful in shifting a person’s beliefs and distress associated with eating disorders. There is also evidence supporting the use of Dialectical Behavioral Therapy (DBT), Family-Based Therapy (FBT), and Interpersonal Psychotherapy for eating disorders. 

Research has found, however, that exploring the past and causes does not effectively help with OCD treatment, for which the gold standard is Exposure and Response Prevention (ERP). ERP is a type of CBT that focuses more on behavior than on changing or challenging cognition. There is promising research on the use of ERP specifically for the treatment of eating disorders. I believe this to be an area that should be explored more because of the similarities between eating disorders and OCD. Acceptance Commitment Therapy (ACT) and Mindful Self-Compassion are great adjunct therapies for OCD and eating disorders. Psychopharmacological treatment has also been shown effective with both populations in addition to psychotherapy.

It’s important to remember that everyone is different and nuance should always be taken into consideration in the diagnosis of OCD and specific eating disorders. For example, because ARFID and Orthorexia may not revolve around weight, body shape, or appearance, their symptoms can be easily misinterpreted as being associated with OCD alone. Recognizing that these disorders can work in tandem, clinicians should always begin by treating the diagnosis that is most negatively impacting the client’s medical stability. Eating disorders are complex disorders that never have one single cause, but when we look at them through the lens of OCD, similarities often emerge. While it’s important not to oversimplify these disorders, understanding these similarities can offer helpful insight. 

OCD and eating disorders are highly treatable

If you think you may be struggling with an eating disorder, it’s important to work with a licensed therapist who has specific experience and training in treating eating disorders. To find clinicians in your area who are qualified to help you recover from eating disorders, you can contact the National Eating Disorders Association helpline.

If you’re struggling with OCD and want to take power away from your intrusive thoughts about food, NOCD can help. Their licensed therapists deeply understand OCD and are specialty-trained in treating OCD with ERP. They work side-by-side with the OCD experts and researchers who designed some of the world’s top OCD treatment programs. You can book a free 15-minute call with their team to get matched with one and get started with OCD treatment.