Bulimia Nervosa: Diagnosis and Criteria

• Eating disorders are characterised by distinctive clinical features in the domains of behaviour, perception, cognition, emotion, social adjustment and physical health.

Diagnostic criteria for bulimia nervosa (DSM-5)

• Involves recurrent episodes of binge eating, characterised by:
  • Eating an amount of food that is larger than what most individuals would eat in a similar period of time under similar circumstances (e.g., within any 2-hour period)
  • A sense of lack of control over eating during the episode
• Recurrent inappropriate compensatory behaviours to prevent weight gain, such as self-induced vomiting, misuse of laxatives, diuretics, or other medications, fasting, or excessive exercise
• Binge eating and compensatory behaviours occur, on average, at least once a week for 3 months
• Self-evaluation is unduly influenced by body shape and weight
• Disturbance does not exclusively occur during episodes of anorexia nervosa

Diagnostic criteria for bulimia nervosa (ICD-10)

• Persistent preoccupation with eating and an irresistible craving for food, with episodes of overeating in which large amounts of food are consumed in short periods of time
• Attempts to counteract the fattening effects of food by:
  • Self-induced vomiting
  • Purgative abuse
  • Alternating periods of starvation
  • Use of drugs such as appetite suppressants, thyroid preparations, or diuretics
  • Neglect of insulin treatment in diabetic patients
• Psychopathology consists of a morbid dread of fatness and a sharply defined weight threshold, well below the premorbid weight
• There is often but not always a history of an earlier episode of anorexia nervosa, ranging from a few months to several years, expressed, or a moderate loss of weight and/or a transient phase of amenorrhea could occur

Diagnostic criteria for anorexia nervosa (DSM-5)

• Restriction of energy intake relative to requirements, leading to a significantly low body weight
• Intense fear of gaining weight or of becoming fat, or persistent behaviour that interferes with weight gain
• Disturbance in the way in which one's body weight or shape is experienced

Diagnostic criteria for anorexia nervosa (ICD-10)

• Body weight is maintained at least 15% below that expected or a Quetelet's body mass index of 17.5 or less
• Weight loss is self-induced by the avoidance of fattening foods, self-induced vomiting, self-induced purging, excessive exercise or use of appetite suppressants or diuretics
• Body image distortion in the form of a specific psychopathology whereby a dread of fatness persists as an intrusive, overvalued idea
• Endocrine disorder involving the hypothalamic-pituitary-gonadal axis:
  • Manifest in women as amenorrhea
  • Manifest in men as a loss of sexual interest and potency
  • Elevated levels of growth hormone
  • Raised cortisol levels
  • Changes in the peripheral metabolism of the thyroid hormone
  • Abnormalities of insulin secretion
• If the onset is prepubertal, the sequence of pubertal events is delayed or arrested

Anorexia nervosa

• First described in modern medical literature by Charles Lasègue in France in 1873 and by Sir William Gull in the UK in 1874
• Characterised by emaciation, an inadequate and unhealthy eating pattern and an excessive concern with the control of body weight and shape.

Bulimia nervosa

• Proposed as a separate condition from anorexia in 1979 by Gerard Russell in the UK

DSM-5 & ICD-10 Definitions

• Anorexia nervosa is characterised primarily by weight loss
• Bulimia nervosa is characterised by a cyclical pattern of bingeing and purging.

Restricting vs Binge-Purge Types

• Distinctions exist in DSM between restricting and binge-purge types of anorexia

Binge eating disorder

• Involves uncontrollable episodes of overeating leading to obesity which cause considerable distress
• Sometimes likened to bulimia without vomiting or laxative use

Behavioural patterns linked to Anorexia

• Restrictive eating is typical
• Clients are often thin or emaciated
• Baggy clothes are often worn to conceal weight loss

Behavioural patterns linked to Bulimia

• Typically are of normal weight
• Cycle of restrictive eating, bingeing and compensatory behaviours are typical
• Situations interpreted as threatening or stressful lead to a negative mood state, which precipitates a bout of bingeing
  • These situations include interpersonal conflicts, isolation and small violations of a strict diet
  • Bingeing may also arise from alcohol intoxication

Factors common to both Anorexia and Bulimia

• Bingeing brings immediate relief but leads to physical discomfort and guilt
• Purging relieves guilt and physical discomfort but may also induce shame and fear of negative consequences
• Self-destructive behaviours are often construed as self-punishments for not living up to perfectionistic standards or attempts to escape from conflicts with self-worth and individuation

Perception in Eating Disorders

• Distortion of body image
• Clients perceive body parts to be larger then they are
• Low interoception - Difficulty interpreting internal gastrointestinal and emotional stimuli - Difficulty to know when to start/ stop eating and how to interpret feelings and emotions

Cognition in Eating Disorders

• Preoccupation with food as a consequence of dietary restraint
• Low self-esteem and low self-efficacy leads to
  • ED clients viewing themselves as worthless
  • Achieving a slim body shape and low body weight through dietary restraint as the route to an increased sense of control over their lives/ increased self-worth
• Perfectionist tendencies and to attain exceptionally high standards can perpetuate the negative feelings
• There is an association with increased inflexibility in anorexia
• Conflict concerning personal dependence vs maturity
  • Fear of maturity and independence coupled with wish to escape from parental control and the lack of autonomy and privacy that this entails

Emotion in Eating Disorders

• Intense fear of fatness and depressed mood arising from dietary restraint
• Low mood lead to bingeing which brings temporary relief. However, after binges, low mood may occur, as a result of the sense of failure that this entails
• Suicide attempts
  • Up to 20% of patients with anorexia
  • 25% with bulimia
  • Associated with depression, substance misuse, and a history of child physical and sexual abuse

Social Adjustment in Eating Disorders

• Withdrawal from peer relationships
• Deterioration of family relationships
• Poor educational or vocational performance

Physical Health in Eating Disorders

• Health complications of anorexia involving an endocrine disorder affecting the hypothalamic-pituitary-gonadal axis
• Starvation symptomatology - Reduced metabolic rate, Bradycardia, Hypotension, Hypothermia and Anaemia

Features related to Bulimia only

• In bulimia, erosion of dental enamel from vomiting
• Lesions may develop on the back of the dominant hand if the hand is used to induce vomiting

Factors that are concerns for both Anorexia and Bulimia

• Electrolyte abnormalities are a concern and may lead to a fatal arrhythmia

Binge eating disorder

• Characterised by uncontrollable over-eating and obesity and it is like bulimia without vomiting and laxative use
• Involves feeling a loss of control and eating a large amount of food over a short time

Aetiological Factors

• When people try to slim through restrained eating, they experience hunger and negative affect and become preoccupied with food.
• Those who develop anorexia redouble their efforts to maintain a pattern of restrained eating,
• While those who develop bulimia engage in bingeing and later in compensatory purging
• Involve Genetic, Temperamental, Sociocultural, Personality, Biomedical, Cognitive-Behavioural and Interpersonal Factors

Genetic Factors

• Evidence from twin and family studies show that genetic predisposing factors contribute moderately to the etiology of eating disorders and that they are 50–83% heritable
• There is some evidence that appetite and satiety dysregulation renders people vulnerable

Temperamental Factors

• Genetic factors contribute to temperamental dispositions that underpin the development of personality traits associated with EDs
• Predisposing personality traits of perfectionism, harm avoidance and depression may be the personality traits which place people at risk
• Compulsivity and inflexibility may be the personality traits that place people at risk for developing restrictive-anorexia-like disorders
• Impulsivity and novelty-seeking may lead to disinhibited-bulimic-like eating disorders
• Environmental factors play a key role in the aetiology of eating disorders

Sociocultural Factors

• Eating disorders exist internationally, but are more prevalent in Western societies where food is plentiful and dieting is promoted
• More prevalent among groups under greater social pressure to achieve the slim aesthetic ideal
• Higher in ethnic groups that move from a culture that does not idealise the thin female form to cultures that do
• Not all dieters develop anorexia or bulimia
• Precipitating factors contribute to the development of EDs

Life stresses and personality factors

• Life stress
• Absence of social support
• Negative affectivity
• The internalisation of a thin-ideal body image
• Possibly predispose to developing EDs

Background predisposing personality factors

• Childhood helplessness
• Childhood adversity
• Low self-esteem
• Rigid perfectionism

Intermediate predisposing factors

• Dietary restraint
• Low shape- and weight-based self-esteem
• Disgust of food and food-related body stimuli
• Bodily shame

Biomedical Factors

• Starvation laboratory experiments show similar neuroendocrine abnormalities in patients with EDs
• More pronounced changes occur in anorexia compared with bulimia
• Most of the starvation-related neuroendocrine changes occur in the hypothalamic-pituitary-gonadal axis that governs reproductive functioning

Neuroimagining studies

• Anorexia and bulimia lead to reduced cortical mass and altered functioning of the taste and reward processing regions of the brain, with some degree of normalisation after recovery
• Rigid obsessionality and difficulty set-shifting are predisposing neuropsychological traits for anorexia which are exacerbated by starvation-related biological abnormalities
• EDs expression of an underlying mood disorder

Evidence that supports links with mood

• There is a link between abnormalities in the serotonergic neurotransmission system that contribute to dysregulation of mood as well as appetite and impulse control in eating disorders
• SSRIs and TCAs have been found to lead to short-term improvements in bulimia, but limited impact on anorexia nervosa
• CBT plus SSRIs may be effective for bulimia

Cognitive-behavioural maintaining factors

• Once a ED is precipitated by life stresses, cognitive and behavioral factors maintain the disorder
• Predisposing factors contribute to the development of negative beliefs
• Core beliefs lead to the development of assumptions
• Develop during childhood, but they only cause an effect when the patient is activated

Core Belief

• ‘I am worthless,’ ‘I am unlovable’ or ‘I am unattractive.’

Assumptions

• 'I must be thin to be attractive, successful or happy,' 'I must do everything perfectly, for people to love me' or 'I must punish myself to be good.'

Negative Automatic Thoughts

• These distorted thoughts maintain restrained eating in both anorexia and bulimia
• Family and peer group approval for thinness also reinforces dietary restraint

Inbulimia

• A period of restraint in some situations leads to binge eating, which in turn triggers guilt for over eating and related negative automatic thoughts about shape and weight, which in turn leads to compensatory, laxative, and dietary

Treatment

• For young adults with bulimia, CBT is the treatment of choice
• Therapist identifies chains of events, thoughts, emotions and motivations that explain how the ED is established and maintained and helps develop better strategies to cope with this

Cognitive Distortions

• All-or-nothing thinking: Thinking in extreme categorical terms
• Catastrophizing: Thinking about the worst possible outcome and assuming it will definitely occur
• Magnification and minimization or discounting positive qualities: Exaggerating the significance of negative experiences or personal weaknesses and discounting the significance of positive experiences or personal strengths
• Selective attention: Selectively attending to information that is consistent with a negative view of the self
• Selective abstraction: Selectively focusing on a small aspect of a situation and drawing conclusions from this
• Overgeneralization: Generalizing from one instance to all possible instances
• Personalization: Attributing real or imagined negative characteristics to the self without supportive evidence
• Emotional reasoning: Taking feelings as facts
• Mental filtering: Focusing on one negative aspect of a situation and filtering out all positive aspects of the situation
• Mind-reading: Assuming without evidence that other people are thinking negative things about you
• Double standards: Having more stringent standards for the self than for others

Interpersonal Maintaining Factors

• In interpersonal therapy (IPT) for bulimia it is assumed that the four categories of interpersonal difficulties maintain eating disorders
• Involves grief, role disputes, role transitions and interpersonal deficits
• Family factors are a subset of interpersonal factors that maintain eating disorders

Dysfunctional families

• Report worse family functioning than other families
• Attempts to cope with eating disorders inadvertently maintain problematic eating habits
• Can be treated with the Maudsley model of family therapy of eating disorders to treat adolescents with their parents

Psychodynamic Maintaining Factors

• Psychoanalytic explanations of EDs focus on the role of intrapsychic factors in the origin and maintenance of eating pathology
• Mothers of anorexic girls adopt a parenting style in which parental needs for control and compliance take primacy over the child's needs for self-expression and autonomy
• Leads to difficulties learning how to interpret need-related internal physiological states and developing a coherent sense of self separate from caregivers

Cognitive-behavioural Therapy

• Providing information about the nature and effects of eating disorders
• Keeping a record of eating habits, body image and emotional states to identify patterns, triggers and consequences of disordered eating behaviours
• Restructuring cognitions (beliefs and assumptions) about food, weight and shape with evidence based thinking
• Addresses interpersonal issues
• Anticipate and plan for setbacks or triggers that may lead to relapse
• Monitor with a compassionate and non-judgemental manner

To conduct an assessment for a patient with an eating disorder:

• Gather background information
• Assess the patient's physical health
• Evaluate the patient’s mental health
• Assess eating disorder severity
• Identify strengths and resources
• Develop a treatment plan
• Monitor progress