Source: Abnormal Psychology Textbook (University of Florida)
Difficulty: Intermediate | Prerequisites: Parts 1 and 2 (clinical presentations of anorexia, bulimia, BED, OSFED)
Tags: eating disorder aetiology, biological factors, sociocultural factors, cognitive factors, emotion regulation, CBT for eating disorders, family therapy, Maudsley model, IPT, SSRIs, hypothalamus, serotonin, thin ideal, dichotomous thinking, abnormal psychology chapter 12
Understanding why eating disorders develop requires pulling from multiple levels of explanation: genetics and neurobiology, sociocultural pressure, cognitive style, emotion regulation, and family dynamics. No single factor is sufficient on its own. Treatment mirrors this complexity. The most effective interventions combine psychological and, in some cases, biological approaches. CBT has the strongest evidence base for bulimia and binge-eating disorder, while anorexia remains harder to treat. This section covers the full causal picture and the major treatment modalities.
Eating disorders arise from a combination of genetic vulnerability, brain chemistry, societal pressure to be thin, cognitive distortions (perfectionism, dichotomous thinking), difficulties managing emotions, and family dynamics. CBT is the most supported therapy for bulimia and BED. Anorexia is harder to treat; family therapy (Maudsley model) shows promise for adolescents. Medications can help but are generally less effective than therapy alone.
Hypothalamus
A brain structure that plays a central role in regulating hunger, eating, and body weight. Dysfunction in the hypothalamus, or in the neurotransmitters and hormones it interacts with, may contribute to eating disorders.
Serotonin
A neurotransmitter involved in mood, appetite, and impulse control. Deficiencies in serotonin are associated with carbohydrate cravings and may drive the binge-purge cycle in bulimia. In simple terms, low serotonin can make a person crave carbs, binge on them, and then purge.
Thin ideal internalisation
The process by which a person adopts society's standard of thinness as their own personal goal. Women who internalise the thin ideal promoted by media are at elevated risk for eating disorders. Think of it as moving from "society says thin is good" to "I believe thin is good and I must achieve it."
Dichotomous thinking
An all-or-nothing cognitive style in which things are judged as entirely good or entirely bad. In eating disorders, this manifests as believing that any break in a strict eating routine means total loss of control.
Cognitive behavioural therapy (CBT)
A structured psychotherapy that targets distorted thinking and maladaptive behaviours. For eating disorders, CBT addresses overvaluation of thinness, teaches clients to monitor and challenge thoughts about eating and weight, reintroduces avoided foods, and establishes regular meal patterns.
Maudsley model (family-based treatment)
A family therapy approach for adolescent anorexia. Over 10 to 20 sessions across 6 to 12 months, parents are coached to take control of their child's eating and weight, and the child's growing autonomy is explicitly linked to resolution of the eating disorder.
Interpersonal therapy (IPT)
A therapy focused on interpersonal problems related to the eating disorder. The therapist works actively with the client to develop strategies for improving relationships and social functioning.
Dieting subtype (Stice)
A pattern of disordered eating where the person is concerned with body image and tries to maintain a rigid diet, but frequently binges and then vomits or exercises excessively to compensate.
Depressive subtype (Stice)
A pattern of disordered eating driven primarily by depression and low self-esteem. The person eats to manage painful feelings. This subtype carries worse outcomes: more relationship difficulties, higher rates of psychiatric comorbidity, poorer treatment response, and greater likelihood of continued severe binge eating.
Genetics
Anorexia, bulimia, and binge-eating disorder all run in families. Genes carry a general risk for eating disorders rather than a specific risk for one type. Changes in hormones at puberty may activate a genetic vulnerability in girls but not in boys. The social changes that accompany puberty for girls (increased attention to appearance, peer comparison) likely interact with this genetic risk.
Hypothalamus and neurochemistry
The hypothalamus, along with neurotransmitters (norepinephrine, serotonin, dopamine) and hormones (cortisol, insulin), plays a central role in regulating eating.
People with anorexia show lowered function of the hypothalamus and abnormalities in dopamine and serotonin levels. Whether these disruptions are causes or consequences of starvation remains unclear. Some studies show function returns after weight gain; others do not.
People with bulimia show abnormalities in the serotonin system. The proposed pathway: serotonin deficiency leads to carbohydrate cravings, which leads to high-carb bingeing, which leads to purging to avoid weight gain.
Dysfunction in these systems could cause disorders by making the body crave certain foods or making it harder to read internal hunger and satiety signals.
Why people with these disorders develop distorted body image remains unexplained by neurobiological models alone.
Media and the thin ideal
Societal pressure to be thin and attractive contributes to eating disorders, but not everyone exposed to these pressures develops one, so other factors must also be involved. Women who internalise the thin ideal are at particular risk. Anorexia and bulimia are more common in females because thinness is more valued in women (women's magazines contain far more diet content than men's magazines).
The research pathway: greater media exposure promoting thinness leads to greater body dissatisfaction, which leads to higher risk for eating disorders. This combination of thin-ideal internalisation and body dissatisfaction is the strongest predictor of eating disorder development. Women who watched more body-makeover programmes reported higher body dissatisfaction.
Peers and athletes
Peers can be the most effective carriers of appearance-related messages. Athletes face additional pressure to maintain a specific weight and body shape, especially in sports where weight affects competitiveness (gymnastics, ice skating, dancing, wrestling, horse racing, bodybuilding, judo, karate, diving). Female athletes report excessive dieting and exercise to maintain prepubescent figures. Male bodybuilders binge in the off-season and diet before competition. Female weightlifters with eating disorder symptoms often abused ephedrine.
Body dissatisfaction combined with low self-esteem and perfectionism creates a particularly toxic mix
People with eating disorders tend to be more concerned with others' opinions and more susceptible to societal pressures as a result
Dichotomous thinking: the person judges things as entirely good or entirely bad, and believes that any deviation from their eating routine will lead to total loss of control. Days are planned around rigid eating rituals.
Women with eating disorders organise their perceptions of the world around body size
Eating disorders can function as a maladaptive strategy for managing painful emotions. People with depressive symptoms or persistent negative affect are more likely to develop eating disorders. Emotional eating itself is a risk factor (Stice).
Stice and colleagues identified two subtypes of disordered eating involving binge eating:
Dieting subtype: The person is body-conscious and tries to maintain rigid dietary control but frequently loses it, binges, then purges or exercises excessively.
Depressive subtype: The person is concerned with weight and size but eats primarily to manage depression and low self-esteem. This subtype has worse outcomes across the board, including greater social and psychological consequences, more relationship difficulties, higher rates of comorbid psychiatric disorders (especially anxiety), poorer treatment response, and greater likelihood of continued severe bingeing. Women with this subtype are more likely to be diagnosed with major depression or an anxiety disorder.
According to Bruch, families of girls with eating disorders tend to show high levels of conflict, discourage the expression of negative emotions, and emphasise control and perfectionism. For the girl, the eating disorder provides a sense of control and selfhood apart from the family. However, these family characteristics are also seen in families of children with depression and anxiety disorders, so they are not specific to eating disorders.
Other family findings:
Mothers in families affected by anorexia and bulimia are more likely to criticise their daughters' weight and to show distorted eating patterns themselves
Eating and weight concerns in young people can be predicted by the degree of conflict over eating habits and control at mealtimes when the child was five years old
Lack of awareness of body sensations may lead the person to ignore hunger pangs; girls who cannot ignore those pangs may fall into the anorexia or bulimia pattern
Low parental warmth combined with high parental demands or control is associated with daughters developing eating disorders
Family history of binge eating is a risk factor
Caution: studies cannot always determine whether controlling parental behaviour is a cause of the disorder or a response to it (parents may exert control to protect a child who is already ill)
Psychotherapy
Engaging people with anorexia in therapy is difficult. They feel the need to maintain their routines and behaviours, making them resistant to therapeutic change. Building trust is a long process, made harder if the therapist must force hospitalisation because the client's weight has dropped to a dangerous level. Forced hospitalisation and refeeding are sometimes necessary, as many individuals do not seek help until they are already malnourished and in medical crisis.
Psychotherapy can help, but it is a long process. Those who improve often relapse and continue to experience self-esteem issues, family problems, depression, and anxiety.
Cognitive behavioural therapy (CBT) for anorexia
The most researched psychotherapy for anorexia. CBT confronts the overvaluation of thinness and ties rewards to weight gain. In hospital settings, privileges may be contingent on eating and gaining weight. Relaxation techniques may be taught for anxiety about food intake. CBT can lead to weight gain and symptom reduction, but dropout rates are high and many clients return to disordered eating.
Family therapy (Maudsley model)
The family is treated as a unit. Over 10 to 20 sessions across 6 to 12 months, parents are coached to take control of their child's eating and weight. The child's growing autonomy is linked explicitly to resolution of the eating disorder. This approach can be successful for girls with anorexia.
CBT for bulimia (strongest evidence)
CBT is the most supported treatment for bulimia. It is built on the view that extreme concerns about shape and weight are central to the disorder. The therapist teaches the client to monitor the thoughts that accompany eating, especially around binge and purge episodes, and helps the client confront those thoughts and develop healthier attitudes toward weight and body shape.
The behavioural component involves reintroducing "forbidden" foods and challenging irrational beliefs about them. Clients are taught to eat three regular meals a day and to question thoughts about weight gain.
Treatment typically lasts 3 to 6 months (10 to 20 sessions). Outcomes include cessation of the binge-purge cycle, reduced depression and anxiety, improved social functioning, and decreased preoccupation with dieting and weight. CBT is more effective than medication and better at preventing relapse long-term.
Expanded CBT approaches that also address emotion-regulation difficulties are effective for people with co-occurring eating disorders and depression.
Comparison of therapies
CBT has been compared with interpersonal therapy (IPT), supportive-expressive psychodynamic therapy (SEPT), and behavioural therapy (BT):
IPT focuses on interpersonal problems related to the eating disorder and actively develops strategies
SEPT encourages the client to discuss eating-related problems in a non-directive manner
BT teaches food-intake monitoring, reinforces reintroduction of avoided foods, and teaches coping skills to avoid bingeing
All four produce significant improvements, but CBT and IPT show the greatest and most enduring gains. CBT is significantly more effective than IPT for bulimia and works more quickly. Both are equally effective at preventing relapse.
CBT for binge-eating disorder
CBT is also the most effective treatment for BED, reducing binges and overconcern with weight, shape, and eating.
SSRIs such as fluoxetine (Prozac) reduce binge-eating and purging behaviours, but do not restore normal eating habits on their own
Combining CBT with antidepressant treatment increases recovery rates
Antidepressants are used to treat anorexia and can reduce symptoms
Olanzapine (an atypical antipsychotic) can increase weight in people with anorexia
SSRIs, antiepileptic medications (e.g. topiramate), and obesity medications (e.g. orlistat) are all better than placebo at reducing binge eating, but they do not tend to reduce concerns about body shape or weight
Students sometimes assume sociocultural pressure alone causes eating disorders. Plenty of people are exposed to the thin ideal without developing a disorder. Biological vulnerability, cognitive style, emotion regulation, and family factors all interact with cultural pressures.
A common error is treating the neurobiological findings (serotonin deficiency, hypothalamic dysfunction) as established causes. In many cases, it is unclear whether these are causes or consequences of starvation and disordered eating.
Students often overlook the depressive subtype of disordered eating (Stice). This subtype carries distinctly worse outcomes and is worth knowing as a separate entity.
It is tempting to assume that medication alone can treat eating disorders effectively. In practice, CBT outperforms medication for bulimia and BED, and combining the two is better than medication alone.
⚠️ Know the multi-factor model: genetics + neurochemistry + sociocultural pressure + cognitive factors + emotion regulation + family dynamics.
⚠️ The serotonin-carbohydrate-binge-purge pathway for bulimia is commonly tested.
⚠️ Thin-ideal internalisation plus body dissatisfaction is the strongest predictor of eating disorders. Be able to explain this chain.
⚠️ Know the Maudsley model details: who it is for (adolescent anorexia), how many sessions (10 to 20), time frame (6 to 12 months), and the core principle (parental control linked to the child's growing autonomy).
⚠️ CBT is the gold-standard therapy for bulimia and BED. Know what it involves (monitoring cognitions, reintroducing forbidden foods, three meals a day, 10 to 20 sessions over 3 to 6 months).
⚠️ CBT vs. IPT: CBT works faster for bulimia, but both are equally effective at relapse prevention.
⚠️ SSRIs reduce binge-purge behaviours but do not restore normal eating. CBT + medication outperforms medication alone.
True or false: Genes carry a specific risk for one type of eating disorder rather than a general risk across types.
Fill in the blank: Deficiencies in __________ are associated with carbohydrate cravings and the binge-purge cycle in bulimia.
True or false: CBT is more effective than IPT for treating bulimia and works more quickly.
Fill in the blank: The Maudsley model involves ______ to ______ sessions over 6 to 12 months.
True or false: SSRIs alone are sufficient to restore normal eating habits in people with bulimia.
Answers: 1. False (genes carry a general risk across eating disorder types). 2. Serotonin. 3. True. 4. 10 to 20. 5. False (SSRIs reduce binge-purge behaviours but do not restore normal eating habits; CBT is needed alongside).
Q: Describe the serotonin pathway that may contribute to bulimia nervosa.
A: Deficiencies in serotonin lead to cravings for carbohydrates. The person binges on high-carbohydrate foods to satisfy these cravings, then purges to avoid weight gain. The cycle repeats because the underlying serotonin deficit is not resolved.
Q: What is the strongest predictor of eating disorder development according to the research discussed in this chapter?
A: The combination of thin-ideal internalisation (adopting society's standard of thinness as a personal goal) and body dissatisfaction. Greater media exposure promoting thinness leads to more body dissatisfaction, which leads to higher eating disorder risk.
Q: Compare the dieting and depressive subtypes of binge eating identified by Stice.
A: The dieting subtype is driven by body concern and rigid dietary control; the person binges when control fails, then compensates. The depressive subtype is driven by depression and low self-esteem; the person eats to manage painful feelings. The depressive subtype has worse outcomes, including more social and psychiatric problems, worse treatment response, and a greater chance of continued severe bingeing.
Q: Why is it difficult to engage people with anorexia in psychotherapy?
A: People with anorexia feel that their eating routines and control over food are essential to their self-worth. They resist changes to their thinking and behaviour. Trust-building is especially hard if the therapist must force hospitalisation due to dangerously low weight, and most individuals do not seek treatment until they are already in medical crisis.
Q: What does the Maudsley model of family therapy involve, and for whom is it designed?
A: The Maudsley model is designed for adolescents with anorexia. It involves 10 to 20 sessions over 6 to 12 months. Parents are coached to take control of their child's eating and weight. The child's autonomy is linked explicitly to the resolution of the eating disorder, so the child regains independence as they recover.
Q: Why are biological therapies alone insufficient for treating eating disorders?
A: Medications such as SSRIs can reduce binge-eating and purging behaviours, but they do not restore normal eating habits or address the cognitive and emotional factors that maintain the disorder (overvaluation of thinness, body dissatisfaction, dichotomous thinking, emotion regulation difficulties). Adding CBT to medication increases recovery rates because CBT targets these underlying psychological factors.
The biological factors here connect to neuroscience and psychopharmacology topics covered elsewhere in abnormal psychology, particularly the role of serotonin in mood disorders and impulse control. The cognitive factors (dichotomous thinking, perfectionism, concern with others' opinions) overlap with cognitive models of depression and anxiety disorders. Family dynamics link to developmental psychology and to the study of how parenting styles influence psychopathology. The treatment section connects to the broader therapy comparison literature, especially debates about CBT vs. other modalities.
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