Eating disorders are complex mental health conditions that affect an individual’s relationship with food and body image. A common question is whether someone can simultaneously have diagnoses of both anorexia nervosa and bulimia nervosa. While symptoms may appear to overlap, current diagnostic guidelines generally do not allow for a simultaneous diagnosis of both conditions. This distinction is important for accurate assessment and appropriate treatment.
Defining Anorexia Nervosa
Anorexia nervosa is characterized by restricting energy intake, leading to a significantly low body weight. Individuals with this condition often experience an intense fear of gaining weight or becoming fat, or engage in persistent behaviors that interfere with weight gain, even when at a low weight. There is also a disturbance in how one’s body weight or shape is perceived, an undue influence of body weight or shape on self-evaluation, or a persistent lack of recognition of the seriousness of their current low body weight.
Anorexia nervosa has two main subtypes. The restricting type involves weight loss primarily through dieting, fasting, or excessive exercise, without recurrent episodes of binge eating or purging. The binge-eating/purging type includes recurrent episodes of binge eating or purging behaviors, such as self-induced vomiting or misuse of laxatives, diuretics, or enemas, alongside the core criteria of significantly low body weight.
Defining Bulimia Nervosa
Bulimia nervosa is defined by recurrent episodes of binge eating. A binge-eating episode involves consuming a large amount of food in a discrete period, accompanied by a sense of lack of control over eating during that time. Following these binges, individuals engage in recurrent compensatory behaviors to prevent weight gain. These behaviors can include self-induced vomiting, misuse of laxatives, diuretics, or other medications, fasting, or excessive exercise.
For a diagnosis of bulimia nervosa, both the binge eating and compensatory behaviors must occur at a specified frequency. Self-evaluation in individuals with bulimia nervosa is influenced by body shape and weight. A key diagnostic criterion is that these disturbances do not occur exclusively during episodes of anorexia nervosa, meaning individuals with bulimia nervosa are not at a significantly low body weight.
Navigating the Diagnostic Criteria
According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), a person cannot be diagnosed with both anorexia nervosa and bulimia nervosa simultaneously. The distinguishing factor between these two conditions, particularly when binge eating and purging behaviors are present, is body weight. If someone exhibits behaviors associated with bulimia nervosa, such as recurrent binge eating and compensatory behaviors, but is also at a significantly low body weight, their diagnosis would be anorexia nervosa, binge-eating/purging type.
This diagnostic hierarchy exists because the presence of a significantly low body weight in anorexia nervosa indicates a more severe medical risk and takes precedence. Bulimia nervosa is diagnosed when recurrent binge eating and compensatory behaviors occur in the absence of significantly low body weight. This distinction helps ensure individuals receive appropriate and targeted treatment.
When Symptoms Overlap or Evolve
While simultaneous diagnoses of anorexia nervosa and bulimia nervosa are not made, individuals may experience symptoms that overlap or transition from one eating disorder to another over time. For instance, someone initially diagnosed with anorexia nervosa (restricting type) might later develop binge-eating and purging behaviors while remaining at a low body weight, leading to a diagnosis of anorexia nervosa, binge-eating/purging type.
Similarly, an individual with bulimia nervosa might, over time, restrict their food intake to a significantly low body weight, which would then lead to a diagnosis of anorexia nervosa. Diagnostic crossover, particularly from anorexia nervosa to bulimia nervosa, is common. The presence of disordered eating behaviors and associated distress indicates a need for professional evaluation and support.