Prevalence of mental health disorders in anorexia nervosa
The first step in understanding the mental effects of anorexia nervosa is looking at the overlap between AN and mental health disorders. According to a large national study in the United States, 83.7% of individuals with AN experience another psychiatric disorder at some point during their lives. (2) Some of the most common mental health conditions co-occurring with anorexia nervosa, based upon the percentage of patients who will experience each condition alongside AN during their lifetimes, are as follows: (2)
- Depression: 49.5%
- Persistent depression: 22.4%
- Generalized anxiety disorder: 21.9%
- Panic disorder: 21.0%
- PTSD: 22.7%
- Substance use disorder: 60.3%
- Borderline personality disorder: 30.3%
The relationship between anorexia nervosa and mental health
It is clear that psychiatric conditions like depression and anxiety are common in individuals who struggle with anorexia nervosa, but what is less clear is whether AN leads to mental health disorders, or vice versa. One study found that having anorexia nervosa increases the risk of later being diagnosed with another psychiatric disorder by almost four times. Similarly, the risk of later being diagnosed with anorexia nervosa after being diagnosed with a psychiatric disorder is increased by over four times compared to not having a psychiatric diagnosis. (3)
It is not possible to conclude from correlational data if having AN causes other psychiatric disorders or if other psychiatric disorders cause AN. As anorexia nervosa often develops as a response to or a coping mechanism for traumas, stressful life events, or other mental health struggles, it is likely that in many cases, AN co-exists with these other conditions regardless of the order in which they were formally diagnosed.
Because it can result in significant appearance changes and urgent physical symptoms, AN may be diagnosed more quickly than co-occurring psychiatric disorders that co-exist with it or even predate it. (6) However, some people who have “atypical” presentations of AN that do not involve significant weight loss or reaching a very low weight (which is actually more common than low-weight AN) may receive a delayed diagnosis, regardless of their level of distress or medical complications. All of this is to say that co-occurring mental health conditions are very common with anorexia nervosa, but many complicating factors mean that the order in which these conditions are diagnosed cannot be used to determine a causative relationship between them.
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Potential causes of mental side effects in anorexia
For some people, anorexia nervosa may increase the risk of later developing a mental health condition, but sometimes, understanding the mental side effects of AN is not as straightforward. Recent research has given us more information about this connection, though it is still not fully understood.
One factor that has been identified as contributing to mental health side effects in anorexia nervosa is difficulties with emotional regulation. Numerous studies have found that patients with anorexia nervosa have a difficult time managing negative emotions, and one study revealed that significant energy restriction actually improves emotional regulation abilities for individuals with anorexia nervosa, presumably because reduced food intake changes the activity of neurotransmitters within the brain. (4)
For some people, it may be that anorexia nervosa develops as an unhealthy coping mechanism for other emotional and mental health symptoms, but for others, mental side effects of anorexia nervosa may appear after the onset of the eating disorder. Changes in the structure of the brain and the activity of neurotransmitters that can result from malnutrition may also contribute to the development of depressive symptoms secondary to AN. (7)
The Bottom Line
Anorexia nervosa can have a negative effect on mental health. Not only is AN a mental health condition in and of itself; individuals with an anorexia nervosa diagnosis have nearly quadruple the risk of being diagnosed with another mental health condition compared to individuals without AN. (3)
For some people, psychiatric disorders may be a precursor to the later development of an eating disorder such as anorexia nervosa. For instance, symptoms of anxiety and depression may place a person at a higher risk of developing a fixation on food, body size, and weight. Eating disorders and mood disorders can also exist in a vicious cycle in which mood disorders can trigger eating disorder behaviors like obsessing over body appearance and restricting calories, which can be quite isolating and lead to shame and self-loathing , which ultimately worsen mental health.
Regardless of the exact cause of other mental health disorders that may be comorbid with anorexia nervosa, what is most important is that patients receive a comprehensive treatment program that addresses both eating disorder symptoms and symptoms of co-occurring mental health disorders. With individualized treatment, patients can learn healthy coping strategies and develop the tools for managing stressors without turning to eating disorder behaviors.