PSY353 Chapter Notes - Chapter 8: Bulimia Nervosa, Binge Eating, Eating Disorder
Chapter 8: Eating and Sleep-Wake Disorders
MAJOR TYPES OF EATING DISORDERS:
Chief characteristic: overwhelming, all encompassing drive to be thin
1. Bulimia nervosa – binges (out-of-control eating episodes) are followed by self-induced vomiting, excessive use of
laxatives, or other attempts to purge the food
2. Anorexia nervosa – person eats only minimal amounts of food or exercises vigorously to offset food intake so body
weight sometimes drops dangerously
3. Binge-eating disorder – individuals may binge repeatedly and find it distressing, but do not attempt to purge the food
Anorexia nervosa → highest mortality rate of any psychological disorder (including depression)
• 20% die as a result
• 5% dying within 10 years
• 6 times the increase in death rates from eating disorders compared with death rates in the normal population
• 20-30% of anorexia-related deaths are suicides → 50 times higher than the risk of death from suicide in the general
population
• Suicide attempts are common among people with eating disorders → affecting 30-40% of patients at least once
Eating disorders are widespread and increased dramatically in Western countries from 1960-1995
• 1975-1986 → referral rates for anorexia rose slowly
• rates for bulimia rose dramatically → 0 to 140 per year
• rates for bulimia may be levelling off or even beginning to drop
• Higher prevalence of eating disorders in younger age groups born 1972-1985 → especially bulimia
• Earlier ages of onset for anorexia and bulimia in recent years
Eating disorders were included for the first time as a separate group of disorders in DSM-IV
• Strong contributors to aetiology → sociocultural rather than psychological or biological
Eating disorders tend to be culturally specific (especially bulimia)
• not found in developing countries → access to sufficient food is a daily struggle
• only in the West have they been rampant
Eating disorders are going global
• estimates of prevalence in Japan and China → approaching those in US and other western countries
Eating disorders tend to occur in a relatively small segment of the population → specificity in terms of sex and age is
unparalleled
• 90% of severe cases → young females who live in a socially competitive environment
• seek one another out on the Internet → pro-ana, pro-mia, thinspiration websites and social networks → found support
and inspiration (negative)
Obesity – produced by the consumption of a greater number of calories than are expended in energy
• behaviour that produces distorted energy equation contradicts a common assumption:
• people with obesity do not necessarily eat more or exercise less → they do
• tendency to overeat and exercise too little has a genetic component
• excessive eating is why obesity could be considered a disorder of eating
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Obesity is not considered an official DSM disorder
• one of the most dangerous epidemics confronting public health
• 70% of adults in the US are overweight
• 35% meet criteria for obesity
• 100M people in US are dieting at any one time
• rates are increasing for decades → but levelling off in North America
Body Mass index (BMI) – highly correlated with body fat → basis for definitions of underweight, overweight, and obesity
• undernourishment: BMI < 18.5
• obesity: BMI > 30
The more overweight someone is at a given height, the greater risks to health → greater increased prevalence of:
- cardiovascular disease
- diabetes
- hypertension
- stroke
- gallbladder disease
- respiratory disease
- muscular skeletal problems
- hormone-related cancers
BULIMIA NERVOSA
• One of the most common psychological disorders on college campuses
• Overwhelming majority of individuals with bulimia are within 10% of their normal weight
BULIMIA NERVOSA CLINICAL DESCRIPTION
Hallmark 1: eating a large amount of food, typically more junk food than fruits and vegetables, than most people would eat
under similar circumstances
• Patients readily identify with this description
• Actual caloric intake for binges varies from person to person
Hallmark 2: Eating is experienced as out of control → criterion that is an integral part of the definition of binge eating
Hallmark 3: individual attempts to compensate for the binge eating and potential weight gain by purging techniques:
- Self-induced vomiting immediately after eating
- Using laxatives (relive constipation)
- Diuretics (result in loss of fluids through greatly increased frequency of urination)
- Exercise excessively (more usually a characteristic of anorexia nervosa) → 57% of bulimic vs 81% of anorexic
- Fast for long periods between binges
Bulimia nervosa was subtyped in DSM-IV-TR into:
1. Purging type – vomiting, laxatives, or diuretics
2. Nonpurging type – exercise and/or fasting → quite rare (6-8% of bulimics)
• Little evidence of any differences between 2 types
• No differences in severity of psychopathology, frequency of binge episodes, or prevalence of major depression and
panic disorder
• Distinction was dropped in DSM-5
Purging is not an efficient method of reducing caloric intake
• Vomiting reduced 50% of the calories just consumed → less if it delayed
• Laxatives and related procedures have little effect → acting so long after the binge
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Over-concern with body shape → important psychological characteristic added to the DSM-IV-TR criteria
• e.g. continuing popularity and self-esteem would largely be determined by the weight and shape of her body
• only 3% of 107 women seeking treatment for bulimia did not share this attitude
Major features of the disorder: bingeing, purging, over-concern with body shape
• cluster together in someone with this problem
• strongly supports the validity of the diagnostic category
BULIMIA NERVOSA MEDICAL CONSEQUENCES
Chronic bulimia with purging has a number of medical consequences:
1. Salivary gland enlargement caused by repeated vomiting → chubby face appearance
2. Repeated vomiting may erode the dental enamel on the inner surface of the front teeth
3. Repeated vomiting may tear the oesophagus
4. Continued vomiting may upset the chemical balance of bodily fluids (Na and K levels)
• Electrolyte imbalance – can result in serious medical complications if unattended:
• Cardiac arrhythmia (disrupted heartbeat), seizures, renal failure
• Normalisation of eating habits will quickly reverse the imbalance
5. Develop more body fat
6. Intestinal problems resulting from laxative abuse (severe constipation or permanent colon damage)
7. Marked calluses on their fingers or the backs of their hands caused by friction of contact with the teeth and throat
(from stimulating gag reflex)
BULIMIA NERVOSA ASSOCIATED PSYCHOLOGICAL DISORDERS
Individual with bulimia usually presents with anxiety
• 80.6% of bulimics had an anxiety disorder at some point during their lives
• 66% if bulimic adolescents presented with co-occurring anxiety disorder when interviewed
• patients with anxiety disorders do not necessarily have elevated rates of eating disorders
Mood disorders (especially depression) also commonly co-occur with bulimia
• 20% of bulimics meeting criteria for a mood disorder when interviewed
• 50-70% meeting criteria at some point during course of disorder
• Theory: eating disorders are simply a way of expressing depression
• BUT depression follows bulimia and may be a reaction to it
Substance abuse commonly accompanies bulimia nervosa
• 36.8% of bulimics and 27% of anorexics were also substance abusers when interviewed
• even higher lifetime rates of substance abuse
Shared risk factors of novelty seeking and emotional instability → accounted for the high rates of comorbidity between bulimia
and anxiety and substance use disorder
• factors differed between males and females
Bulimia seems strongly related to anxiety disorders and somewhat less so to mood and substance use disorders
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Document Summary
Anorexia nervosa highest mortality rate of any psychological disorder (including depression) 6 times the increase in death rates from eating disorders compared with death rates in the normal population. 20-30% of anorexia-related deaths are suicides 50 times higher than the risk of death from suicide in the general population. Suicide attempts are common among people with eating disorders affecting 30-40% of patients at least once. Eating disorders are widespread and increased dramatically in western countries from 1960-1995. Earlier ages of onset for anorexia and bulimia in recent years. Eating disorders were included for the first time as a separate group of disorders in dsm-iv. Strong contributors to aetiology sociocultural rather than psychological or biological. Eating disorders tend to be culturally specific (especially bulimia) not found in developing countries access to sufficient food is a daily struggle only in the west have they been rampant.
