Anorexia Nervosa in Adolescent Patients: What You Need to Know

Eating disorders are among the most prevalent, disabling, and potentially fatal psychiatric illnesses, and the COVID-19 pandemic has exacerbated their burden, with a 15.3% increase in incidence in 2020 compared with previous years.¹ This increase was almost solely among adolescent girls with anorexia nervosa (AN), which is often insidious in onset and more difficult to treat as it advances.

Adolescents with AN are most likely to present to their pediatricians, so awareness and early recognition of the symptoms is critical. Pediatricians are also an integral part of the treatment team in AN and can offer monitoring for serious complications, alongside valuable guidance to parents, who are central to treatment and the reestablishment of healthy eating habits in their children. Here we will review the epidemiology, diagnosis, and treatment of anorexia, with an emphasis on what pediatricians need to know to screen and to facilitate treatment.

Epidemiology

AN is marked by a fear of gaining weight or behaviors that interfere with weight gain and a self-evaluation unduly influenced by weight and body shape. Youth with AN often deny the seriousness of their malnutrition, although that is not required for diagnosis. AN can be of a restrictive or binge-purge subtype, and amenorrhea is no longer a requirement for diagnosis.

Dr Susan Swick

There is not a specific weight or body mass index cutoff for the diagnosis, but the severity of AN is determined by the BMI percentile normed to age and sex. The average age of onset is 18, and the prepandemic prevalence of AN was about 1% of the population. It affects about 10 times as many females as males. It is quite rare prior to puberty, affecting about 0.01% of that age group. There is a heritable component, with a fivefold relative risk in youth with a parent with AN, and twin studies suggest heritability rates as high as 75%.

Youth with rigid cognitive styles appear more vulnerable, as do those who participate in activities such as ballet, gymnastics, modeling, and wrestling because of the role of appearance and weight in performance. More than half of patients with AN will have another psychiatric illness, most commonly anxiety disorders, depression, or obsessive-compulsive disorder. AN becomes chronic in up to 15% of sufferers and the mortality rate is close to 10%, with approximately half dying from medical complications and half dying by suicide.

Screening

Parents and pediatricians are usually the first to notice that a child has started to lose weight or is falling off the growth curve. But weight changes usually emerge after feelings of preoccupation with weight, body shape, and body satisfaction. If parents report escalating pickiness around food, increased or compulsive exercise, persistent self-consciousness and self-criticism around weight and body shape, it is worth starting with screening questions.

Dr Michael Jellinek

If you notice preoccupation or anxiety around being weighed, even if the weight or growth curve are still normal, it is worthwhile to screen. Screening questions, such as the SCOFF questionnaire with five simple questions, can be very sensitive for both AN and bulimia nervosa.² There are also many validated screening instruments, such as the Eating Disorder Inventory or Eating Attitudes Test (for adolescents) and the Kids Eating Disorder Survey and the Child Eating Attitudes Test (for younger children), that are short self-reports that you can have your patients fill out when you have a higher index of suspicion. Weight loss or growth failure without a preoccupation around weight or appearance needs a thorough a medical workup, and could be a function of other psychiatric problems, such as depression.

If a child screens positive for an eating disorder, your full physical examination, growth curves, and longitudinal growth charts are critical for diagnosis. Percentile BMIs must be used, given the inaccuracy of standard BMI calculations in this age group. (Centers for Disease Control and Prevention age and sex growth charts include methods for this calculation).

Laboratory assessment, including metabolic, kidney, pancreatic, and thyroid function, and an EKG can illuminate if there are consequences of restricting or purging. Of course, you want to evaluate for significant medical symptoms, including bradycardia, orthostasis, and hypokalemia. These medical symptoms are not limited to the severely underweight and merit referral to an emergency department and possible medical admission.

Then, a referral to a clinician who is expert in the assessment and treatment of eating disorders is needed. This may be a child psychiatrist, psychologist, or a colleague pediatrician with this specialization. It is also very important to begin the conversation with the family to introduce your concerns, describe what you have noticed, and discuss the need for further assessment and possibly treatment.

Be mindful that discussing this in front of your patient may heighten the patient's anxiety or distress. Be prepared to offer support and understanding for your patient's anxiety, while steadfastly providing absolute clarity for the parents about the necessity of further evaluation and treatment. Many parents will be concerned and ready to do whatever is needed to get their child's eating and growth back on track.

But some parents may have more difficulty. They may have their own history with an eating disorder. They may be avoiding a sense of shame or alarm. They may be eager to avoid adding to their child's stress. They may be tired of engaging in power struggles with the child. They may be proud of their ambitious, accomplished young athlete. Their trust in you makes you uniquely positioned to complicate their thinking. And treatment will hinge on them, so this is a critical bridge to care.

Beyond telling parents that they will need to bring more structure and supervision to mealtimes to begin addressing their child's nutrition, you might offer guidance on other strategies. Empower parents to limit their child's use of social media sites such as Instagram, YouTube, and TikTok, where they may be immersed in comparing themselves to idealized (and airbrushed) influencers. Empower them to make their child's participation in beloved sports contingent on eating meals together and completely or on a stabilized weight (as will be common in treatment). Remind them that there are no bad foods, that the goal is health, and that they are not in a power struggle with their child, but instead allied with their child to treat AN. Remind them to also look for chances to have fun with their child, to help everyone remember what matters.

Treatment

Family-based therapy (FBT) is the first-line treatment of shorter-duration AN in children and adolescents. It focuses on the parents, helping them to calmly and effectively manage their child's eating behaviors until their weight and behaviors have normalized. As a patient's nutritional status improves, so does cognitive function, emotional flexibility, and mood.

Individual therapy and psychopharmacologic treatment can be very effective for comorbid anxiety, mood, attentional, and thought disorders. Family-based work does include the child and is often done in group-based settings with clinicians from multiple disciplines. Dietitians provide education and guidance about healthy nutrition to the child and parents. Therapists may work with the child, parents, or full family to focus on behavior modification and managing distress.

Most academic medical centers provide access to FBT, but there are many regions with no providers of this evidence-based treatment. One of the silver linings of the COVID-19 pandemic is that several online services have emerged offering FBT, working with families to manage mealtimes and treatment entirely at home.³ Pediatricians provide regular medical checks to measure progress and help with decisions about when it is safe to permit exercise or advance privileges and independence around eating. Some pediatricians have discovered a deep interest in this area of pediatrics and built their practices on it. Given the surge in prevalence of AN and the needs for adolescent mental health services, we hope more will do so.

Swick is physician in chief at Ohana, Center for Child and Adolescent Behavioral Health, Community Hospital of the Monterey (Calif.) Peninsula. Jellinek is professor emeritus of psychiatry and pediatrics, Harvard Medical School, Boston. Email them at pdnews@mdedge.com .

References:

1. Taquet M et al. Br J Psychiatry. 2022;220:262-4.

2. Morgan JF et al. West J Med. 2000 Mar;172(3):164-5.

3. Matheson BE et al. Int J Eat Disord. 2020 Jul;53(7):1142-54.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

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