Chapter 8 " Eating disorders"

Biological Factors for Eating Disorders

Many are born with genetic or biological predisposition toward certain neurological features or personality characteristics. Eating disorders have some genetic basis, but environmental risk factors are also important in the development of these disorders. • Genetics: ED's do run in families & some people seem genetically predisposed toward certain ED's. Modest heritability (.42) has been reported in general. Genes on chromosomes 1, 4, and 10 may contribute to these dispositions—stronger genetic component for anorexia restricting type. No one set of genes or gene leads directly to an ED. Genes likely set the stage for the brain or neurochemical features that lead to ED or with environmental events to trigger Eds. Brain structures most likely involved in eating problems are the hypothalamus & amygdala; Hypothalamus that regulates hunger, eating & is involved in appetite. Damage to the lateral hypothalamus lead to weight & appetite changes in animals. Other researchers have focused on the connection of the lateral hypothalamus with the amgydala. This seems related to learned cues that surround eating. These cues override feelings of satiety & promotes more eating.

sociocultural factors

family conduct maltreatment or trauma family emphasis in thinness cultural pressure to be thin media exposure

Eating Disorder

intense weight concern worry and distress about body.

Psychological factors

low self steem body dissatisfaction distorted body image perfectionism

3 major features of eating disorders are 1) weight concerns, 2) body dissatisfaction & 3) eating problems.

1) Weight Concerns Feeling overweight much of the time Viewing one's weight negatively 2) Body Dissatisfaction Distress with one's appearance 3) Eating Problems Restricted Eating or Dieting Lack of Control over Eating

Epidemiology of Eating Disorders

Eating disorders are not as common as anxiety-related or depressive disorders. Symptoms of eating disorders are also common among adolescents & young adults with other mental disorders. Peak age of onset for eating disorders is 15 to 19 years old. Mortality is significantly associated with anorexia in many countries. Eating disorders have the highest death rate of any major mental disorder—Average age at the time of death is 49 to 61 years. Approximately 6% of undergraduate women have concern about anorexia or bulimia; & 25% to 40% reported moderate problems regarding weight control, worry about body image & lack of control about eating. Many do NOT seek treatment. Only 23.2% of those with an eating disorder seek mental health care. People may not seek treatment due to embarrassment, shame or stigma. Many are secretive about their symptoms & believe there is no problem. Women are much more likely to have anorexia nervosa or bulimia nervosa than men. Sociocultural reasons include the objectification of women, media models of thinness, stress from maltreatment, sexual harassment, poor recognition of achievements, & excessive attention to beauty & body shape. Also more common with gay men / men on rise wrestling. Bulimia nervosa is primarily found in Western cultures & may be a culture-bound disorder. For women, the goal or focus is body weight versus For men, the goal is body shape or body size.

Environmental Risk Factors for Eating Disorders

Family Factors: -a leading factor is substantial reinforcement given by family members to a person who has lost weight & thus is thought to possess great self-discipline or self-control. Some family members also express a preference for thinness. Mothers & daughters often diet, have an eating disorder, & display perfectionism. Families with eating disorders can be intrusive, controlling, hostile, disorganized, & unsupportive. Conflict with mothers & fathers & less maternal intimacy relate to weight concerns. Family members of people with EDs also make frequent & negative comments re: body shape & weight. Media Exposure: -especially in Western society, the media promotes the "thin ideal." In the U.S., beauty queens, models, and Playboy bunnies have become increasingly thin over the past 50 to 60 years. Young girls are influenced by the media's depiction of attractiveness & ideal body Cognitive Factors: -Major risk factors are body dissatisfaction & body image disturbance. Family & media can influence body dissatisfaction. Body image disturbance refers to faulty self-evaluation of one's body weight & shape despite contradictory evidence Cultural Factors: -European-American women do NOT differ from Latinas or Asian-American women with respect to body dissatisfaction. European-American women report higher level of body dissatisfaction than African-American women. This may reflect greater acceptance of body weight & shape with AFAM women & that they are raised to be more independent, strong & self-reliant making them less susceptible to the thin ideal & self-acceptance

Biological Factors

Genetics Neurobiology Mood regulation Stress reactivity impulse regulation

anorexia nervosa

People with anorexia nervosa refuse to maintain a minimum, normal body weight, have an intense fear of gaining weight

compensatory behaviors for bulimia Nervosa:

compensatory behaviors: induced vomiting, laxative misuse, diuretics, and enemas. Bulimia nervosa is marked by binge eating, inappropriate methods to prevent weight gain non purging compensatory behaviors: fasting for several days.

• Binge-Eating Disorder:

must occur on average once a week for at least 3 months. eating more rapidly that normal, eating despite feeling uncomfortably full, eating large amounts even when not hungry, eating alone because of embarrassment over the quantity of food consumed, & feeling disgusted or guilty. amount of food that is larger than what most would, LACK OF CONTROL. •The major difference between bulimia nervosa and binge eating disorder is that with binge-eating disorder: the person does NOT engage in compensatory behaviors such as purging (e.g., vomiting), excessive exercise, or fasting.

Features of Bulimia Nervosa

• Binge-eating episodes • Inappropriate methods to prevent weight gain • Self-evaluation greatly influenced by body shape & weight Episodes often triggered by depression, stress • Dental Problems • Swelling of salivary glands • Esophageal problems • Chronic diarrhea • Bowel problems

Biological factors

• Neurochemical Features: serotonin, dopamine, and endogenous opioids are also influential. • Serotonin: influences mood regulation, impulsivity, & eating behavior • Satiety • Dopamine: linked to pleasurable aspect of food and motivation to obtain food • Endogenous Opioids: body chemicals that reduce pain, enhance positive mood & They are released during starvation & after intense exercise suppress appetite • Personality Traits: Perfectionism is a risk factor for EDs especially among young people • Perfectionism • Impulsivity: binge eating has a desperate & urgent quality