Eating disorders and substance abuse

Question 1

What are the characteristic features of anorexia nervosa?

Answer 1

The primary focus is starving
Refusal to maintain healthy body weight, intense fear of weight gain, distorted body perception and amenorrhoea
Elaborate food rituals
Death rate is 5-8%

Question 2

What are the two types of anorexia nervosa?

Answer 2

Restricting type
Binge/purge type - very occasional binge/purge sessions while still primarily restricting, often also accompanied by intense and obsessive exercise

Question 3

What are the 10 key complications of anorexia nervosa?

Answer 3

NS - can’t think straight, fear of weight gain, irritability, fainting etc
Hair - thinning and brittle
Heart - low BP, slow heart rate, palpitations
Blood - anemia
Muscles/joints/bones - weak muscles, swollen joints, bone loss, fractures and osteoporosis
Kidneys - kidney stones and failure
Body fluids - low potassium, magnesium and sodium
Intestines - constipation and bloating
Hormones - periods stop, trouble with pregnancies
Skin - bruise easily, dryness, growth of fine hair everywhere, brittle nails

Question 4

Why can death result from anorexia?

Answer 4

Multiple organ failure as brain prioritised when delegating remaining fuel and many body systems just don’t get enough to survive

Question 5

What happens in Bulimia Nervosa?

Answer 5

Recurrent cycles of binge eating followed by extreme behaviours to prevent weight gain e.g. vomiting
Binge eating episodes occur over short time period (~20 mins) during which there is COMPLETE lack of control over what is being eaten - usually triggered by period of low mood and self-esteem, often tied to body image issues and need for self-punishment

Question 6

What is the binge-eating-purging cycle like in Bulimia?

Answer 6

Can happen at least twice a week and condition diagnosed when this has been going on for at least 3 months

Question 7

How does bulimia compare to anorexia?

Answer 7

Mortality rate isnt as high and individuals usually maintain a stable body weight because of intervening periods in which they pretty much eat normally
Can still suffer from related side effects of the repeated purging/laxatives

Question 8

What are twelve key complications of Bulimia?

Answer 8

Brain - depression, fear of weight gain, anxiety, low self-esteem
Cheeks - swelling and soreness
Mouth - cavities, enamel erosion, gum disease
Throat/oesophagus - sore and irritated, can tear and rupture so blood in vomit
Muscles - fatigue
Stomach - ulcers and pain, can rupture, delayed emptying
Skin - abrasion of knuckles, dryness
Heart - irregular heart beat, low pulse, weakened heart muscle, low BP
Blood - anaemia
Body fluids - dehydration, low potassium etc.
Intestines - constipation, irregular BMs, bloating, diarrhoea, cramping
Hormones - irregular/absent periods

Question 9

What is binge eating disorder?

Answer 9

Regular binging without purging i.e. no behaviours for preventing weight gain
Sometimes binges happen when stressed, and like bulimia the binging occurs very rapidly almost in a daze, unaware of what they are eating and with no control over the behaviour

Question 10

What are some complications of binge eating disorder?

Answer 10

Resemble those of obesity:
High BP and cholesterol
T2 diabetes
Gallbladder disease
Joint pain
Cancer
Sleep apnoea

Question 11

What are the biological factors involved in producing an eating disorder?

Answer 11

Genetic factors such as predisposition to depression
Dysregulation of hypothalamus and abnormal hypothalamic appetite systems - anorexic individuals actually show a greater release of insulin in response to food despite their cognitive denial of hunger; mismatch between physiology and cognition thought to be related to abnormal levels of agouti-related peptide
Serotonin imbalance and abnormalities in serotonergic neurotransmission
Alterations in functioning of dopamine-based reward systems w

Question 12

What are some sociocultural/psychological factors involved in eating disorders?

Answer 12

Societal pressure to be thin
Cultural norm that thin=attractive
Using food to cope with negative emotions
Over-concern with opinions of others 
Rigid thinking/perfectionism
Over-controlling parents
History of sexual abuse

Question 13

What have researchers now identified?

Answer 13

Brain function is particularly critical to understanding why people develop eating disorders - specific neurobiological differences in the brains of sufferers which affect how we eat but also mood, anxiety, personality and decision-making

Question 14

How is serotonin implicated in eating disorders?

Answer 14

5HT helps control memory, learning, sleep, mood and appetite
Alterations in serotonin system in anorexics and even those who have recovered - lower levels of serotonin metabolites in CSF, sign of starvation since 5HT synthesised from food we eat
After long term recovery we see significantly elevated levels, corresponding with higher anxiety and obsessive behaviours
Also thought to be link to particular serotonin receptor which increases amount of serotonin in brain during non-starved state

Question 15

What effect does starvation have on the body?

Answer 15

Actually makes anorexics feel better because it decreases serotonin, but as starvation continues the brain compensates and increases number of serotonin receptors to more efficiently utilise remaining serotonin.
In order to keep feeling better, they starve themselves more, thus creating the vicious cycle - recovery is difficult because as soon as eat, serotonin spikes causing extreme anxiety and emotional chaos

Question 16

What is the serotonin circuitry like in individuals with bulimia?

Answer 16

When going without food for sustained period e.g. during sleep, they have larger drop in serotonin levels than those without an eating disorder, leading to binge eating and increased irritability
Persistence of abnormalities after recovery suggests that they were there prior to onset i.e. may have contributed to causing the disorder?

Question 17

What are the serotonin alterations in binge eating disorder like?

Answer 17

Similar to those in bulimia, but research is more limited
Believe that these individuals suffer from CHRONICALLY LOW serotonin levels, which contributes to binge eating in an attempt to relieve the depressed mood caused at least partially by this lack
Studies have supported this - association between impulsivity/strict dieting and serotonin receptor genes and binge eating

Question 18

What is the general role of dopamine in the body?

Answer 18

the pleasure chemical, linked to rewarding behaviours and drug abuse
Involved in reward-motivated behaviour and also helps regulate movement, memory, hormones and sensory processing

Question 19

How is dopamine implicated in anorexia?

Answer 19

Over-production of dopamine, leading to anxiety and thus harm avoidance, hyperactivity and ability to go without pleasurable things like food (high anxiety –> intense fear of eating as eating produces a further dopamine spike)

Question 20

How is dopamine implicated in bulimia?

Answer 20

Lower levels of dopamine and certain dopamine receptors

Binge eating is associated with dopamine release

Question 21

How is dopamine implicated in binge eating disorder?

Answer 21

Condition linked to hyper-responsiveness to rewards such as food, making it more pleasurable and rewarding for these people than normal, leading to continuation of compulsive over-eating through over-activation of opiate and dopaminergic reward mechanisms
The binging essentially resembles a drug addiction

(Other causes can be genetic mutations in receptors that should signal satiety)

Question 22

How is norepinephrine implicated in eating disorders?

Answer 22

Hormone released by adrenal medulla and by sympathetic nerves, controlling feelings of motivation, reward and pleasure
People with eating disorders have decreased levels

Question 23

Essentially, how is the brain affected in eating disorders?

Answer 23

Several brain areas become imbalanced/may already be predisposed to imbalance and thus function differently
Factors involved in eating disorders, such as maladaptive eating behaviours, interact with elements such as psychological traits - do existing psych traits produce the maladaptive behaviours or the other way around?

Question 24

What are the key psychological traits implicated in anorexia and bulimia?

Answer 24

Anorexia - greater levels of neuroticism and low impulsivity
Bulimia - higher levels of impulsivity and novelty seeking behaviours

Such traits may be existing, or may be worsened by behaviours which then also go on to influence brain circuitry e.g. pathways involved in habit learning and reward processing

Question 25

What are 3 of the key brain regions involved and the circuitry based there?

Answer 25

Limbic system - fear learning/generalisation; abnormalities here and resulting emotional imbalance feed back into psychological traits and insecurities regarding things like body image
Ventral frontostriatal - reward processing and behavioural/cognitive control; it is this dopamine reward system that is altered in eating disorders, with severe food restriction plus at-risk genetic-environmental vulnerabilities leading to this alteration and subsequent binding of self-starvation and associated cues with motivational value (in normal individuals they have neural compensatory mechanisms to prevent this)
Dorsal frontostriatal - habit learning

Question 26

What happens once an eating disorder is established?

Answer 26

Connections between circuitry systems keep changing, and the longer a disorder exists the harder the treatment and rebalancing becomes - CBT isnt always strong enough

Question 27

How can anorexia be treated?

Answer 27

Has to be severe to rectify the maladaptive circuitry which results from genetic, endocrine, personality, cognitive and environmental variables - can include hospitalisation and forced feeding
Less severe options include rewards for eating (rather than restricting which is how their brains get rewired by the condition), relaxation techniques, cognitive support to deal with underlying emotions and family therapy
SSRIs are minimally effective, only used where comorbid depression

Question 28

How can bulimia nervosa be treated?

Answer 28

Involves confronting interpersonal problems associated with the bulimic behaviours, and assistance with reducing the impulsive eating and negative emotions driving it
Some effectiveness of tricyclic antidepressants and SSRIs

Question 29

What is the time course of anorexia nervosa?

Answer 29

In childhood, we see traits such as negative emotions, perfectionism, drive for thinness etc
In adolescence, when puberty hits, brain development, hormones, stress and cultural factors feed in
In adulthood, dieting to aid self-esteem leads to weight loss which leads to the neurobiological changes - a cycle is set up propagated by denial, rigidity, anxiety, depression and obsessions, and 30-50% of people remain chronic in this cycle