The disordered eating habits often brought on by the condition can lead to mood changes, depression, and other side effects, and AN has even been found to impact the physical brain itself.
This complex mental illness can be dangerous or even deadly if left untreated. But with the appropriate help, someone can overcome this illness and avoid the mental effects of anorexia nervosa before it’s too late.
Mental Signs of Anorexia
Anorexia nervosa is often associated with its more physical effects, including the extreme weight loss or severe dietary restriction it brings on. But the disordered eating patterns that characterize AN are actually the byproduct of a mental health condition, which can be recognized by a number of signs.
Some of the most common mental health effects of anorexia nervosa include: [1, 2]
- Social withdrawal
- Frequent checks in the mirror, or fixation on perceived flaws
- Fixation on food, eating, or dietary information
- Preoccupation with body weight, shape, or size
- Intense fear of gaining weight
- Harsh self-criticism, especially about weight or appearance
- Feeling “fat” or overweight when that’s not the case
- Distorted body image (seeing oneself as heavier as one is)
- Fear of certain foods or food groups
- Thoughts of self-harm
Anorexia nervosa also commonly co-occurs with a number of other mental health disorders. Co-occurring mood disorders such as anxiety and depression are the most prominent, but AN also frequently occurs alongside obsessive compulsive disorder (OCD) and substance use disorders. 
What Can Anorexia Do to the Brain?
Anorexia nervosa isn’t just a mental health disorder. It can have an actual physical impact on the brain.
The eating disorder has been linked in several studies to changes in brain structure. Some findings have shown that AN and the malnutrition it commonly brings on can lead to changes in the thickness of the cerebral cortex or the outer layer of the brain.  Other studies have connected anorexia nervosa to a loss of gray matter, the brain cells that help the organ process information and stimulate movement, among other responsibilities. 
These types of changes have been noted as far back as 1985. In these initial studies, people with AN were found to have both wider gaps between the folds in their cerebral cortex and smaller folds.  The finding was especially significant, as the folding patterns in the brain are generally set at birth.
Fortunately, most of AN’s effects on the brain can be reversed with treatment, especially if treatment starts early. 
How Does Anorexia Cause Behavioral Changes?
There are a number of ways anorexia nervosa may lead to behavioral changes in people.
The eating disorder is characterized by a fear of weight gain, and food intake and other attitudes around food or eating will frequently change to accommodate this fear. Skipping meals, refusing to eat around others, or avoiding social situations that involve food are all common markers of AN. [1, 2]
The social isolation that often accompanies the condition can be attributed to these changing behaviors as well, along with the preoccupation with appearance and the commonly co-occurring mood disorders that are often part of AN.
Malnutrition can also have an impact on mood, behavior, and thinking. Poor attention span, trouble learning, poor working memory, and visual perception issues have all been linked to low levels of certain vitamins, nutrients, and other essential dietary components. 
And the structural changes anorexia nervosa can cause in the brain may also contribute to these eating disorder symptoms. Grey matter shrinkage has been found to primarily affect areas of the brain that are key to emotion regulation, impulse control, attention, self-regulation, and social interactions. 
How Can You Spot the Mental Effects of Anorexia?
As with other mental health disorders, early intervention and treatment of anorexia nervosa is crucial for overcoming any related medical complications, including the mental effects of anorexia. 
Since people with AN frequently try to hide their condition or the effects of their behavior, it can be difficult to spot these issues. Some signs to look out for include: [1, 2]
- Mood swings
- Increased irritability and low mood
- Sleep troubles
- Lack of interest in socializing
- Withdrawal from family and friends
- Changes in eating and exercise habits
- Sudden weight loss
- Continual comments about dieting, weight and weight loss, and “burning” off calories
- Mental confusion, memory issues, and sluggish thoughts
If you’re worried a loved one may be struggling with anorexia nervosa, it’s important to talk to them about your concerns. Try to be as empathetic as possible, and truly listen to what they have to say, rather than making accusatory statements. Your loved one may deny that there’s a problem or lash out, but they may also open up to you about what they’re dealing with, which can open up the door to finding them help.
How Does Anorexia Treatment Address Mental Health?
Like bulimia nervosa, binge eating disorder, and other eating disorders, anorexia nervosa is ideally treated with a comprehensive approach that addresses both the physical and emotional aspects of the condition.
Treatment will often include behavioral therapy, group therapy, and family therapy, with the goal of changing the way a person thinks and feels about food and their body. The idea is to help someone develop stronger mental health by helping them develop a healthier relationship with food, eating, and themselves.
Many types of behavioral therapy help someone recognize their unhelpful thought and behavioral patterns. They provide tools and strategies to not only help someone change these thoughts and behaviors but also help them continue to look out for themselves well into their recovery journey.
Some types of therapy additionally focus on previous issues or incidents that may be driving disordered eating behavior and help someone work through these situations, while others work on helping someone build better self-esteem and self-worth that’s not tied to their appearance.
Support groups can also help to provide a healthy outlet where similar individuals can meet and discuss coping mechanisms, learn strategies for recovery, and get support to maintain a healthy weight.
Regardless of which type of therapy someone pursues, however, getting help for anorexia nervosa is the best thing someone can do. It may seem difficult or even impossible to overcome this debilitating disorder, but reaching out is often the first step on the road to recovery.
- Anorexia nervosa. (n.d.). Mayo Clinic. Accessed September 2023.
- Anorexia nervosa. (n.d.). Cleveland Clinic. Accessed September 2023.
- Salbach-Andrae H, Lenz K, Simmendinger N, Klinkowski N, Lehmkuhl U, Pfeiffer E. (2008). Psychiatric Comorbidities among Female Adolescents with Anorexia Nervosa. Child Psychiatry and Human Development; 39:261–272.
- Walton E, Bernardoni F, Batury V, Bahnsen K, Lariviere S, et. al. (2022). Brain Structure in Acutely Underweight and Partially Weight-Restored Individuals With Anorexia Nervosa: A Coordinated Analysis by the ENIGMA Eating Disorders Working Group. Biological Psychiatry; 92(9):730-738.
- Curzio O, Calderoni S, Maestro S, Rossi G, De Pasquale CF, Belmonti V, Apicella F, Muratori F, & Retico A. (2020). Lower gray matter volumes of frontal lobes and insula in adolescents with anorexia nervosa restricting type: Findings from a Brain Morphometry Study. European Psychiatry; 63(1):e27.
- Artmann H, Grau H, Adelmann M, & Schleiffer R. (1985). Reversible and non-reversible enlargement of cerebrospinal fluid spaces in anorexia nervosa. Neuroradiology; 27(4):304–312.
- Dolan RJ, Mitchell J, & Wakeling A. (1988). Structural brain changes in patients with anorexia nervosa. Psychological Medicine; 18(2):349–353.
- Kar BR, Rao SL, & Chandramouli BA. (2008). Cognitive development in children with chronic protein energy malnutrition. Behavioral and Brain Functions; 4:31.
- Jones M. (n.d.). Why Early Intervention for Eating Disorders is Essential. National Eating Disorders Association. Accessed September 2023.