Today we will continue our current theme of eating disorders. Today's topic is bulimia nervosa. In part 1 we will cover an introduction, definitions, diagnostic criteria, epidemiology, and pathogenesis. In part 2 we will cover clinical pearls, physical complications, and treatment.
Today's Content Level: Beginner and Intermediate
Bulimia nervosa (BN) is an eating disorder characterized by recurrent binge eating combined with behaviors intended to counteract the weight gain.
Binge eating = Eating a larger-than-normal amount of food in a discrete time period (2 hours). This is accompanied by feeling out of control during the eating episode such as feeling like they cannot stop eating.
Compensatory behaviors = Behaviors intended to prevent weight gain such as self-induced vomiting, misuse of medications (laxatives, diuretics, other medications), fasting, or excessive exercise.
The term, bulimia nervosa, comes from the Greek term for "ravenous hunger" and a Latin word implying "nervous origin".
Individuals are excessively concerned with body weight. However, unlike patients with anorexia nervosa, they usually maintain a normal body weight (and may even be overweight).
Diagnostic Criteria 2
Recurrent episodes of binge eating.
Recurrent inappropriate compensatory behaviors.
Binge eating and compensatory behaviors occur, on average, ≥ once a week for 3 months.
Undue influence of body weight/shape on self evaluation.
Does not occur exclusively during an episode of anorexia nervosa.
Severity is specified based on frequency of inappropriate compensatory behaviors per week. Mild = 1-3. Moderate = 4-7. Severe = 8-13. Extreme = ≥14. The level of severity may be increased to reflect other clinical symptoms or degree of functional disability.
Lifetime prevalence of BN is ~1.5% in females (studies vary: 0.5-2.5%) and <0.5% in men (studies vary: (0.1-1.3%).
Studies reflect approximately a 10:1 female to male ratio.
Most common age of onset is in adolescence or young adulthood. Onset before puberty is uncommon.
Tends to be a chronic and relapsing illness, however the course is variable. Has a better prognosis than anorexia nervosa. Symptoms tend to diminish in studies with long-term follow up.
High mortality rate (~2% per decade). This is lower than anorexia nervosa (~5-6% per decade).
As with most psychiatric disorders, the dominant theory suggests BN develops from a combination of genetic, biological, environmental, and psychosocial factors.
Risk factors are similar to anorexia nervosa and include family history of eating disorders (strong genetic concordance), female gender, age (adolescents and young adults have a higher risk), neglect/abuse/trauma, living in industrialized countries (food is abundant and high social pressure to be thin), poor body image / low self-esteem / dissatisfaction with weight, childhood obesity, early pubertal maturation, and participation in sports or activities with an emphasis on weight/size or involve subjective judging and weight classes (gymnastics, ballet, modeling, running, cheerleading, figure skating, wrestling, etc.).
Certain psychodynamic theories and personality traits have also been associated: obsessive-compulsive personality traits, difficulty differentiating emotional from visceral sensations, and exaggerated values of control / achievement / perfectionism.
Next lesson we will continue part 2 of bulimia nervosa as we discuss clinical pearls, physical complications, and treatment. If you want more learning resources then check out our recommended resources page.
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