Autism and Anorexia – Examining the Correlation

Autism—or autism spectrum disorder (ASD)—and anorexia nervosa (AN) may seem like distinctive mental health experiences, but research suggests they may not be as distant as once thought.

As with all eating disorders, anorexia nervosa is a complex illness, caused and maintained by several different biological, environmental, and psychological factors. There’s no singular trait that results in someone developing eating disorders, but some research has pointed to correlations, or statistically significant links, between autism and anorexia nervosa.

What is Autism?

Autism spectrum disorder (ASD) is a neurodevelopmental condition that impacts the way people learn, communicate, and behave. People with this condition may exhibit distinctive perspectives or behaviors that appear to diverge from societal norms.

To be officially diagnosed with ASD, someone must display “deficiencies” in these three areas:¹

• Social-emotional reciprocity, or a balanced give-and-take in social interactions, including initiating and responding to social cues
• Nonverbal communication, including eye contact and body language
• Developing, understanding, and maintaining relationships and social connections

Further, an ASD diagnosis requires someone to meet at least two of the following criteria:¹

• Repetitive behaviors in speech, motor movements, or interaction with objects
• Extreme inflexibility around schedules or ritualized patterns of behavior
• Intense fixation on specific subjects
• Sensory sensitivity, including hypo- or hyperreaction to certain textures, sounds, smells, etc.

Typically, to be part of an autism diagnosis, these traits must be observable over time by caretakers and/or physicians and cause significant impairment in someone’s day-to-day life.¹

What is Anorexia?

Anorexia nervosa is an eating disorder characterized by an extreme fear of gaining weight. It generally involves a severe restriction of calories and types of food one eats, which often—but not always—results in dangerously low body weight.²

Coupled with this fear is an intense fixation on body weight and body image, a connection between self-worth and appearance, and/or failing to acknowledge the significance of extremely low body weight. People with AN also tend to have misguided thoughts about their own physical appearance, often thinking they have larger bodies than they actually do.³

Frequently, people with AN will also fixate on food, diet, and exercise as means to help them control or lose weight. All together, these types of traits make anorexia nervosa one of the most dangerous eating disorders.³

Anorexia and Autism: What’s the Connection?

The connection between anorexia and autism spectrum disorder was first officially noted in 1983 by scientist Christopher Gillberg, who was investigating restrictive eating disorders.⁴ Since then, studies have increasingly examined this comorbidity—or, co-occurring diagnosis.

Research has found that up to 33% of people with anorexia nervosa meet the clinical criteria for ASD.⁵ Related studies show that certain autistic traits are more elevated in individuals with anorexia nervosa, which may help drive or maintain some aspects of the eating disorder.⁶ And traits related to autism spectrum disorder have been shown to persist in many people with AN after recovery.⁷

While research is still ongoing, scientists have identified some shared traits that may account for these overlapping experiences.

Shared Cognitive Traits

One of the most prominent psychological traits linking autism and anorexia is fixation. Both conditions often involve a hyper-focus on particular subjects.^1,3 With AN, those subjects tend to revolve around food, diet, exercise, body weight, and/or body image. In autistic people, fixation is a core trait of the condition, and is often directed at highly specified subjects.¹

A lack of cognitive flexibility—or the ability to adapt to change—is another trait that often manifests in both anorexia and autism.^1,8 With anorexia nervosa, this trait can act as a primary driver for disordered behaviors, often presenting as food-related rituals or perfectionist views on body weight and image.⁹ In ASD, it can look like outbursts or anxiety around changes to familiar schedules or routines, especially in autistic children.¹

Shared Behavioral Traits

Several shared behavioral traits in those with anorexia nervosa and autism spectrum disorder have also been noted over the years. One seminal study on the topic found people with both AN and ASD commonly struggled with:⁷

• Isolation tendencies
• Relating to others
• Feelings of tension during social situations

The study examined what it called “bridge symptoms,” or symptoms of one recognized disorder that may “activate” symptoms of a second disorder, resulting in a dual diagnosis. Between AN and ASD, some of the strongest bridge symptoms revolved around social, emotional, and behavioral traits, including:⁷

• Poor self-confidence
• Anxiety around eating in front of others
• Anxiety around viewing one’s own body

Diagnosing Autism and Anorexia

As a dual diagnosis, autism and anorexia nervosa can be particularly tricky to determine. Traits that may appear to be part of one condition can actually be caused by related—but ultimately different—issues.

For example, people with ASD may exhibit disordered eating behaviors, not because of eating disorder psychopathology, but due to sensory sensitivities and a need for routine that are connected to their autism diagnosis. Similarly, it’s been theorized that certain traits that appear to be part of ASD in some AN patients are actually related to starvation.¹⁰

Other issues may complicate the ability to make this dual diagnosis.

Autism Spectrum Disorder Comorbidity with Other Eating Disorders

Outside of anorexia nervosa, other eating disorders and autism can be more broadly connected.

Avoidant restrictive food intake disorder (ARFID) is another eating disorder commonly associated with ASD.¹¹ Interestingly, ARFID presents similarly to anorexia nervosa, in that patients severely restrict food intake. However, unlike AN patients, those with ARFID aren’t driven by an intense fear of weight gain.¹²

Still, the many overlapping aspects of these conditions can make it challenging to arrive at an accurate diagnosis.

Gender, Autism, and Anorexia

Autism spectrum disorder is more likely to be diagnosed in males, whereas females are much more likely to be diagnosed with anorexia nervosa.⁷ This leaves a vast gulf of individuals who may have both conditions without proper diagnosis.

In particular, autistic women tend to have different autism disorder symptoms than males with ASD. Theories on this discrepancy include the thought that females are more adept at “masking” autism symptoms, and the idea that most current research on ASD, including that which supports clinical diagnosis, is predominantly based on male behavior.¹³

Similarly, research on anorexia nervosa has historically been focused on females. In many ways, this can create an unintentional tunnel vision or bias, which fails to acknowledge the different ways the issue presents in male patients.

Treating Anorexia and Autism

Unfortunately, people who showcased traits of both autism and anorexia have been found to have longer illness duration, more severe symptoms, and a worse response to treatment.⁶ This makes it even more critical for people who may be struggling with these twin conditions to find help.

There is currently no official protocol on treating people with this dual diagnosis, but that doesn’t mean help is not available. Treatments such as cognitive behavioral therapy (CBT), family-based therapy (FBT), and applied behavior analysis (ABA) may be helpful for individuals experiencing one or both of these conditions. In some cases, medication or other types of treatment may be recommended.

Therapists may ask patients to fill out an eating disorder examination questionnaire, put them on an autism diagnostic observation schedule, or both, to help make an official diagnosis. Once the specifics have been determined, a patient can work with a treatment team—including therapists, physicians, nurses, and other medical and support staff—to implement their individual treatment plans and, over time, observe beneficial change.

Finding Help for an Eating Disorder

If you or a loved one is showing signs of anorexia nervosa or any other eating disorder, it’s essential to seek out proper care. Eating disorders don’t go away on their own and rarely get better without specific, tailored treatment.

Luckily, there are many places where assistance is available. Many community programs and local health departments assist with diagnosis, insurance enrollment, or finding appropriate treatment. A trusted physician or therapist can also assist with diagnosis and care.

Wherever you go for help, the most important thing to remember is that it’s never too late to reach out. The journey to recovery can be long, but it’s a path that everyone can take.