Bulimia Nervosa

Stuffed
Didn't play the corresponding interactive case or want to try it again? Click here to do so.

Diagnosis and reasoning

Even a quick glance at this young lady's symptoms and signs is sufficient to suggest that an eating disorder is present; a more careful analysis brings to light the following: - She regularly indulges in episodes of binge-eating - She attempts to prevent weight gain by compensatory behavior, such as purging, fasting, and excessive exercise - Her self evaluation is significantly influenced by her weight and perception of her body image - These symptoms have continued for years on end The above are an almost textbook presentation of bulimia nervosa, and meet the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for the condition. While the binge-eating/purging form of anorexia nervosa can also present with similar symptoms, this is excluded by the presence of a normal body mass index (BMI); in the aforementioned subtype, low body weight is a striking feature. Note that her evaluation should not stop here; individuals with bulimia nervosa are at risk of numerous complications, both mild and severe, which should be looked for and excluded. In particular, purging can result in damage to the teeth and oropharynx (secondary to exposure to gastric acid), and electrolyte disturbances; however, her examination reveals no features of injury, while her serum electrolytes are within normal parameters. Anemia and hypothyroidism are also frequently encountered in these patients, while liver and renal functions may also be deranged; however, her investigations are all normal in this regard. Note also that menstrual disturbances are also common, even if the BMI is normal. However, this patient's menstrual cycles are regular, and of normal length. Last but not least, these patients have a higher that normal incidence of comorbid psychiatric conditions; her family history of depressive disorder makes this possibility even more concerning. However, her clinical findings are not suggestive of depression, while the Beck Depression Inventory (BDI) score is only 6 out of 63 (i.e. not depressed). Cognitive behavioral therapy will help address her preoccupation with body image, weight and food, and low self-esteem, as well as the behavioral aspects of the illness. Concomitant therapy with the antidepressant Fluoxetine will help hasten her recovery. Note that hematinic therapy is not essential, as she is not anemic; nor are antiemetics of value in her management (as the vomiting is self-induced).


Discussion

Bulimia nervosa is a psychiatric condition characterized by recurrent binge eating, which is followed by anxiety, guilt and physical discomfort, which provoke the patient to follow compensatory measures that are inappropriate and potentially harmful. The condition has a significantly higher prevalence in females, with as many as 3% of young women potentially affected. While the etiology underlying bulimia nervosa is still unclear, genetic factors are thought to play a role. Note also that certain types of personalities and lifestyle factors may predispose to the condition - most notably, perfectionism, mood instability and poor impulse control. Stressors in relation to puberty, peer and parental relationships, sexuality, marriage, and pregnancy may also predispose to the disease. These patients typically become symptomatic during adolescence and early adulthood; despite efforts to become thin, their weight is generally normal or above normal; this is a valuable feature which helps distinguish the disease from the purging type of anorexia nervosa. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) of the American Psychiatric Association (APA) defines certain diagnostic criteria for bulimia; these include frequent episodes of binge eating, recurrent inappropriate compensatory behavior in order to prevent weight gain, and self-evaluation unduly influenced by body shape and weight. These symptoms must be exhibited once a week, for a minimum of three months; furthermore, they should not occur exclusively during episodes of anorexia nervosa. Two types of bulimia nervosa have been described; the purging type involves self-induced vomiting, and the abuse of laxatives or diuretics; the non-purging type is characterized by compensatory behaviors other than purging, such as starving and excessive exercise. Note that these patients may experience a variety of complications, both mild and severe. While binge eating alone usually does not result in severe illness, weight gain and abdominal pain and distension are not uncommon; very rarely, gastric rupture may occur. Purging may result in numerous complications, including enlargement of the salivary glands; dental erosion due to the corrosive effect of gastric acid; oral, pharyngeal and hand trauma; and electrolyte imbalances. The management of bulimia nervosa involves both psychological and pharmacological measures. Antidepressants help reduce the incidence of binge eating and purging, and alleviate depressive symptoms and attitudes towards food; the selective serotonin reuptake inhibitor (SSRI) Fluoxetine is the most commonly used agent, although certain tricyclics and monoamine oxidases inhibitors are also effective. Cognitive behavioral therapy (CBT) is the psychotherapy of most benefit; it has an efficacy similar to that of antidepressants, with even lower relapse rates; patients are asked to record their food intake and feelings, this is then followed by feedback on the meal plan, caloric intake, nutritional balance, and avoidance of triggers. Note that the combination of CBT and pharmacotherapy provides better results than either modality alone. Another important aspect of the management is screening and treatment of comorbid psychiatric conditions - particularly, major depression, bipolar disorder, anxiety and substance related disorders, and personality disorders. There is limited data on the long-term prognosis of bulimia; however, the majority of patients are believed to have a good outcome. That said, approximately 30% of patients relapse rapidly, while some may experience symptoms for years. Predictors of a poor prognosis include childhood obesity, substance abuse, and personality disorders.


Take home messages

  1. The presence of a normal or above-normal weight is a key differentiating factor between bulimia nervosa and anorexia nervosa.
  2. These patients may have other comorbid psychiatric conditions such as depression, bipolar affective disorder, substance related disorders, or personality disorders.
  3. Both antidepressants and behavioral therapy are equally effective in these patients; the combination is even more efficacious.

Insightful, fun cases to improve your diagnostic skills

Use your detective skills, strengthen fundamentals faster, and access a wealth of knowledge.

  1. FAIRBURN CG, PEVELER RC. Bulimia nervosa and a stepped care approach to management. Gut [online] 1990 Nov, 31(11):1220-2 [viewed 13 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/2253902
  2. HAY PJ. Understanding bulimia. Aust Fam Physician [online] 2007 Sep, 36(9):708-12, 731 [viewed 13 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/17885703
  3. LILLY RZ. Bulimia nervosa BMJ [online] 2003 Aug 16, 327(7411):380-381 [viewed 13 August 2014] Available from: doi:10.1136/bmj.327.7411.380
  4. MCGILLEY BM, PRYOR TL. Assessment and treatment of bulimia nervosa. Am Fam Physician [online] 1998 Jun, 57(11):2743-50 [viewed 13 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/9636337
  5. MITCHELL JAMES E, CROW SCOTT. Medical complications of anorexia nervosa and bulimia nervosa. Current Opinion in Psychiatry [online] 2006 July, 19(4):438-443 [viewed 13 August 2014] Available from: doi:10.1097/01.yco.0000228768.79097.3e