Summary: 3.5 Basic Human Needs: Eating, Sex & Sleep
Eating Disorders
DIAGNOSTIC AND STATISTICAL MANUAL OF MENTAL DISORDERS (APA,
2013)
Anorexia Nervosa (AN)
Þ Subtypes
o most individuals with the binge-eating/purging type who binge eat also purge through
self-induced vomiting or the misuse of laxatives, diuretics, or enemas
• some individuals with this subtype do not binge eat but do regularly purge after the
consumption of small amounts of food
,Þ Diagnostic Features
o determining whether Criterion A is met, the clinician should consider available
numerical guidelines, as well as the individual’s body build, weight history, and any
physiological disturbances
• adults à body mass index (BMI)
• children and adolescents à BMI-for-age percentile
o Criterion B à intense fear of becoming fat is usually not alleviated by weight loss
o Criterion C à self-esteem is highly dependent on their perceptions of body shape and
weight
• weight loss = impressive achievement and extraordinary sign of self-discipline
• weight gain = unacceptable failure of self-control
o often, the individual is brought to professional attention by family members after
marked weight loss has occurred
• if individuals seek help on their own, it is usually because of distress over the
somatic and psychological consequence of starvation
• anorexic individuals frequently either lack insight into or deny the problem
Þ Associated Features Supporting Diagnosis
o significant and potentially life-threatening medical conditions
• nutritional compromise associated with this disorder affects most major organ
systems and can produce a variety of disturbances
§ most common – amenorrhea, vital sign abnormalities
§ most physiological disturbances are reversible
o depressive signs and symptoms (i.e., depressed mood, social withdrawal, insomnia)
• many of the depressive features may be secondary and some may be sufficiently
severe for an additional diagnosis of MDD
o obsessive-compulsive features, (un)related to food
• preoccupied with thoughts of food (i.e., collect recipes or hoard food)
o other concerns: eating in public, feelings of ineffectiveness, a strong desire to control
one’s environment, inflexible thinking, limited social spontaneity and overly restrained
emotional expressions
• binge-eating/purging type à higher rates of impulsivity and more likely to abuse
alcohol and other drugs
o excessive levels of physical activity
• increase in physical activity often precede onset of the disorder and over the course
of the disorder increased activity accelerates weight loss
o misuse medications (i.e., manipulating dosage)
Þ Prevalence
o 12-month prevalence in young females: 0.4%
o far less common in males than females (10:1 ratio)
Þ Development and Course
o begin: during adolescence or young adulthood
• rarely before puberty or after age 40
o onset: stressful life event
o course and outcome à highly variable
• younger: atypical features, including denying “fear of fat”
, • older: longer duration of illness, more signs and symptoms
o prior to meeting full criteria: period of changed eating behaviour
o some recover fully after a single episode and others experience a chronic course over
many years
o most individuals experience remission within 5 years of presentation
o crude mortality rate (CMR): 5% per decade
Þ Risk and Prognostic Factors
o temperamental
• anxiety disorder or display obsessional traits in childhood à increased risk
o environmental
• historical and cross-cultural variability in the prevalence of anorexia nervosa
supports its association with cultures and settings in which thinness is valued
• occupations and avocations that encourage thinness à increased risk
o genetic and physiological
• increased risk of anorexia nervosa and bulimia nervosa among first-degree
biological relatives of individuals with the disorders
• increased risk of bipolar and depression disorders among first-degree relatives of
individuals w/ anorexia nervosa, particularly binge-eating/purging type
• range of brain abnormalities in anorexia nervosa
Þ Culture-Related Diagnostic Issues
o most prevalent: post-industrialised, high income countries (European countries, US)
o low prevalence: Latinos, African Americans and Asians
• absence of “fat phobia” common in Asia
Þ Diagnostic Markers
o haematology: leukopenia – common w/ loss of all cell types
o serum chemistry: dehydration, reflected by an elevated blood urea nitrogen level
o endocrine: T4 = low-normal range; T3 = decreased levels; females = low serum
oestrogen levels; males = low levels of serum testosterone
o electrocardiography: sinus bradycardia – common
o bone mass: low bone mineral density, with specific areas of osteopenia or osteoporosis
o electroencephalography: diffuse abnormalities may result from significant fluid and
electrolyte disturbances
o resting energy expenditure: significant reduction in resting energy expenditure
o physical signs and symptoms à many are attributable to starvation
• amenorrhea: indicator of physical dysfunction, consequence of weight loss
• prepubertal females: menarche may be delayed
• most remarkable finding: emaciation
Þ Suicide Risk à elevated: 12 per 100.00 per year
Þ Functional Consequences à some individuals remain active; others demonstrate
significant social isolation and/or failure to fulfil academic or career potential
Þ Differential Diagnosis – other possible causes of either significant low body weight or loss
o medical conditions (e.g., AIDS, gastrointestinal disease)
o MDD, schizophrenia, substance use disorders (SUD)
o social anxiety disorder, OCD and body dysmorphic disorder
o bulimia nervosa, avoidant/restrictive food intake disorder
, Þ Comorbidity
o common - bipolar, depressive and anxiety disorders
o OCD, especially w/ restricting type
o alcohol and other substance use disorder, especially w/ binge-eating/purging type
Bulimia Nervosa (BN)
Þ Diagnostic Features
o “episode of binge eating” (A1)
• single episode of binge eating need not be restricted to one setting
• discrete period of time (i.e., limited period, usually less than 2 hours)
o occurrence of excessive food consumption must be accompanied by a sense of lack of
control to be considered an episode of binge eating (A2)
• inability to refrain from eating or to stop eating once started; dissociative quality
o type of food consumed during binge varies both across individuals and for a given
individual à typically tend to eat foods they would otherwise avoid
o individuals w/ bulimia nervosa are typically ashamed of their eating problems and
attempt to conceal their symptoms (i.e., binge eating in secrecy or inconspicuously)
• binge eating often continues until the individual is uncomfortably full
o most common antecedent of binge eating: negative affect
• other triggers: interpersonal stressors, dietary restraint, negative feelings to body
weight/shape or food, and boredom
• binge eating may minimise or mitigate factors that precipitated the episode in short-
term, but negative self-evaluation and dysphoria often are delayed consequences
o purge behaviours or purging
• most common – vomiting
§ relief from physical discomfort and reduction of fear of gaining weight
