The relationship between anorexia and depression is complex. Genetics, environmental factors, and how your brain and digestive system communicate may all influence this common comorbidity.

Anorexia, formally known as anorexia nervosa (AN), is an eating disorder characterized by extreme calorie restriction, behaviors that interfere with weight gain, and a distorted sense of self-image that drives an intense fear of gaining weight.

When you live with AN, disordered eating behaviors may involve dieting, fasting, and excessive exercise. They can also include binging and purging behaviors, overeating followed by elimination through laxatives, vomiting, or enemas.

As a condition that features significant challenges with negative body image, it’s common for AN to co-occur with mood disorders like major depressive disorder (MDD). The link between these two goes beyond a general sense of shared low mood, however.

According to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, (DSM-5-TR), anorexia and depression are common co-occurring (comorbid) conditions.

The DSM-5-TR is an evidence-based, internationally used guidebook outlining diagnostic criteria for mental health conditions. It’s the product of collective research and exists to provide a consensus on global experiences in mental disorders.

It’s estimated that as many as 70% of people living with AN experience comorbid major depressive disorder at some point in their lifetimes.

Why do anorexia and depression commonly occur together?

Multiple factors appear to help forge the link between anorexia and depression, including genetics, environmental factors, and the gut-brain axis.

Early research on anorexia and depression comorbidity suggests a genetic overlap accounts for co-occurring symptoms. This means the genes increasing your risk for anorexia might be some of the same genes responsible for increasing your risk for depression.

Similar findings have been noted in more current literature. A genetic study from 2023 found AN shares 38 unique genetic sites with MDD and 45 unique genetic sites with psychological traits of mood instability.

Environmental factors have also been considered when it comes to AN and MDD. Environmental factors are the external influences that impact a condition. AN and MDD share environmental risk factors such as:

  • traumatic experiences
  • stressful life events
  • negative peer pressures and influences
  • dysfunctional family dynamics
  • cultural and social expectations

In addition to genetics and environmental links, anorexia and depression may naturally impact one another through the gut-brain axis, a communication pathway between your digestive system and your brain.

This direct connection in the body is why feeling unhappy can make you not want to eat and why eating certain foods can affect your mood.

According to research, alterations in the gut may contribute to mood disorders like depression. A prospective study from 2021 found increasing nutritional imbalances in AN contributed to the progression of co-occurring anxious-depressive symptoms.

Anorexia and depression are very different mental health conditions, but they can share some overlapping symptoms, such as:

  • fatigue
  • weight loss
  • mood disturbances like irritability, feelings of sadness, and a sense of emptiness
  • appetite changes
  • negative body image
  • low self-worth
  • social withdrawal
  • inappropriate guilt
  • sleep disturbances

Anorexia is classified as an eating disorder by the DSM-5-TR. Its core features involve the restriction of energy intake, extreme weight loss behaviors driven by a fear of weight gain, and distorted body image.

While other feelings of low mood are common in AN, they aren’t necessary to receive a diagnosis.

Major depressive disorder is a mood disorder. Its core symptoms involve persistent, pervasive experiences of low mood, loss of motivation, cognitive and physical impairment, and chronic low energy.

Appetite and weight changes are one of 9 possible diagnostic symptoms, but they’re not necessary for the diagnosis of MDD.

Anorexia symptoms

Symptoms of anorexia outlined in the DSM-5-TR include:

  • deliberately restricting energy intake below standard requirements for current age, sex, height, and developmental stage
  • intense fear of gaining weight or being overweight
  • fear-driven behaviors intended to interfere with weight gain, like excessive exercising or purging
  • distorted body image perception
  • lack of recognition of the seriousness of current low body weight

Depression symptoms

Symptoms of depression outlined in the DSM-5-TR include:

  • depressed mood (sadness, emptiness, hopelessness) nearly all day, every day
  • loss of interest or pleasure in almost all activities nearly all day, every day
  • significant weight fluctuations and appetite changes
  • excessive sleepiness or sleeplessness
  • restlessness or slowed motor functions
  • excessive feelings of worthlessness or inappropriate guilt
  • fatigue nearly all day, every day
  • poor concentration or focus
  • indecisiveness
  • recurrent thoughts of death or dying
  • suicide ideation

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you are not in the same household, stay on the phone with them until help arrives.

Anorexia and depression have a two-way relationship, meaning they both impact one another. Depression can make the symptoms of anorexia worse and make recovery more challenging.

A systematic scoping review from 2020 found comorbid depression in AN made gaining weight more difficult during anorexia recovery for some people.

Similarly, anorexia may negatively impact depression symptoms by causing changes in the gut that affect mood and worsen symptoms.

Both anorexia and depression can be treated with psychotherapy (talk therapy) and medications, but approaches are tailored to address specific underlying challenges in each disorder.

For example, cognitive behavioral therapy (CBT) is a cornerstone of both AN and MDD treatment. CBT is a therapy framework that helps you identify and recognize unhelpful thought patterns and behaviors. You then work with your therapist to restructure those thought patterns into new, beneficial ones.

In AN, CBT focuses on your relationship with food and body image. In depression, CBT focuses on broader patterns of negative thinking. In both conditions, CBT helps you learn to recognize warning signs that may signify a relapse of symptoms and teaches you new coping strategies.

Other therapy and treatment formats may be used to meet specific needs in either condition. Interpersonal therapy (IPT), for example, is used in AN and MD to help address different aspects of interpersonal dynamics.

Anorexia and depression can overlap in medications that help improve mood symptoms, regulate sleep, and address physical symptoms. In severe cases, AN may require emergency medical treatment if weight and energy intake are too low to support the body’s basic functions.

AN may also require additional medical approaches, like working with a registered dietitian (RD).

Anorexia and depression are conditions that commonly occur together. Genetics, environmental factors, and the gut-brain axis may all play a role in this comorbidity.

Psychotherapy and medications can help treat both conditions, but your treatment plan will vary depending on the specific concerns being addressed. While they share some symptoms, anorexia and depression are very different conditions that require individualized approaches.