Advances in Genetics and Biological Research Have Changed Understanding of Anorexia Nervosa Within Medical Community
Anorexia nervosa is a life-threatening eating disorder that typically begins in early adolescence. Advances in genetics and biological research have changed our understanding of anorexia nervosa.
Anorexia nervosa was once thought of as a condition chosen by adolescents in response to family difficulties but, recent research suggests that genetics has much to do with the onset of anorexia. In fact, one recent study involving more than 31,000 twins showed that genetics accounts for a majority of the risk of developing anorexia.
Because adolescence is the typical age of onset for anorexia, it was previously assumed that problems with adolescent development were responsible for anorexia. It is likely that psychological factors have some bearing, but it is difficult to prove theories that describe anorexia as a defense against the emergence of sexual development, difficulty separating from parents and enmeshed family dynamics.
Advances in understanding anorexia are welcome, given that anorexia is a life-threatening disorder. In addition to extreme weight loss, an intense fear of gaining weight, distorted body image and amenorrhea, there’s a greater than 80 percent chance that patients with anorexia will have other psychiatric disorders. Depression, anxiety, personality disorders, attention deficit disorder, obsessive-compulsive disorder and bipolar disorder are common, complicating the treatment of patients with anorexia.
The prevalence of co-occurring disorders is just one reason why it is so challenging to treat patients with anorexia.
Current Anorexia Treatment Options
Anorexia treatment varies greatly from patient to patient, depending on the severity of the illness and the philosophy of the anorexia treatment team.
A “continuum of care” treatment model is ideal for anorexia, as patients can advance through a continuum of treatment options as they progress toward recovery, or step back to more intensive treatment at the first sign of a relapse. Seriously ill patients require specialized inpatient treatment that includes intensive medical management of weight restoration and close attention to nutritional needs. Patients requiring inpatient care typically are 15 to 20 percent below their normal weight, have delusional thoughts about food and body image, and have developed electrolyte abnormalities or have not succeeded in outpatient treatment. Patients with anorexia symptoms that are less severe can be treated in a partial hospitalization program, while a multidisciplinary team approach in an outpatient setting is appropriate for those who are not in medical danger from their anorexia.
At each level, several types of treatment are needed, including medical management, individualized therapy and psychoeducation. Controlled studies show that for patients under age 18, the chances of recovery improve if family therapy is included as part of their anorexia treatment.
While cognitive behavioral therapy (CBT) is frequently used in both inpatient and outpatient settings, it has limited efficacy for treating severely malnourished patients with multiple psychiatric conditions. A recent study published in American Journal of Psychiatry found that supportive therapy is superior to cognitive therapy when treating anorexia.
More randomized, controlled treatment studies are needed to gain a better understanding of the role of behavioral therapy in treating anorexia.
Limited Medical Options
No medications for treating anorexia have been approved by the U.S. Food and Drug Administration, so medical management options are very limited.
With few options, antidepressants are the most frequently prescribed drugs for treating anorexia. Antidepressants are prescribed to more than 60 percent of anorexia patients – even though there is no evidence that they help. Two recent articles challenge the use of SSRI antidepressants, including Prozac, Zoloft and Paxil, to treat anorexia. The Journal of the American Medical Association, for example, published the results of a randomized, controlled trial showing no benefit from the use of Prozac.
Cyproheptodine (Periactin), an antihistamine, has been shown to help some patients gain weight and reduce symptoms of depression. Atypical antipsychotics, including Olanzapine (Zyprexa) and Risperidone (Risperdal), have proven effective for helping anorexia patients gain weight, and reduce the anxiety and delusional thoughts associated with anorexia treatment failures. Controlled trials of these medications are currently being investigated.
Targeted Nutrition Therapy
Vitamin and mineral deficiencies have rarely been studied in anorexia patients, in spite of the severe weight loss from self-starvation that is characteristic of anorexia. And while patients with anorexia are profoundly malnourished, it is rare for them to receive nutrient recommendations beyond a multivitamin and calcium.
Controlled research studies support the use of zinc in the treatment of anorexia, yet the medical community has been slow to integrate it into treatment programs. Research from as early as the 1970s suggests that a zinc deficiency may play a role in the onset of anorexia. Zinc is one of the most prevalent trace elements found in the brain. Symptoms of zinc deficiency include decreased appetite, weight loss, altered taste, depression and amenorrhea.
Today’s adolescents typically have diets that are low in zinc and high in inhibitors of the absorption of zinc. Meat and fish are the best sources of zinc, while many plant and wheat products impair absorption of zinc.
Not surprisingly, other nutritional deficiencies are also prevalent in patients with eating disorders. Symptoms of B vitamin deficiency overlap with many of the symptoms of anorexia. Scientific research and professional recognition also support the critical role that essential fatty acids (EFAs) play in brain function.
Anorexia patients avoid fat intake for long periods, with significant consequences on brain function. Omega-3 fatty acids, which are found primarily in fish, cannot be manufactured by the body and must be acquired through diet. Omega-3 fatty acids play a central role in nerve cell membranes from early development through adulthood.
Research supports a relationship between EFA deficiency, and many medical and psychiatric conditions. Depression, attention deficit hyperactivity disorder and bipolar disorder are all thought to be related to deficiencies in EFAs. A recent study showed improvement in patients receiving one gram each of EFAs in addition to standard treatments.
Still Much to Learn about the Causes and Treatment of Anorexia
We still have much to learn about the causes and treatment of anorexia, but nutrition therapy holds promise and should provide encouragement to those who suffer, or have loved ones who suffer, from this complex disorder.
By James Greenblatt, M.D.
Chief Medical Officer of Walden Behavioral Care