Eating disorders Flashcards
Define eating disorders
Disorders involving a definite disturbance of eating habits &/or weight control which results in physical &/or psychosocial functioning impairments
Given the different sub-types of eating disorder, how might we best distinguish between anorexia nervosa and bulimia nervosa?
Anorexia is a more extreme version of bulimia in as much as anorexia diagnosis requires you to be clinically under-weight
What are the 4 main symptoms of anorexia nervosa?
1) Refusal to maintain weight at/above the minimally normal weight for your age/height, 2) Intense fear of gaining weight, 3) Body image disturbance & 4) Amenorrhea (absence of 3 consecutive menstrual cycles)
What are the 4 main symptoms of bulimia nervosa?
1) Recurrent binge eating which is perceived to be uncontrollable, 2) inappropriate compensatory behaviour (vomiting, laxatives & excessive exercise), 3)…twice per week for 3 months & 4) self-evaluation which is unduly influenced by body shape & weight
What are the 2 types of anorexia?
Restricting type vs. binge eating/purging type (done to comfort the worries of friends or family)
What are the 2 types of bulimia?
Purging type vs. non-purging type
What are eating disorders NOS?
(Not Otherwise Specified) Atypical eating disorders which are clinically significant but do not conform to the diagnostic criteria of AN nor BN
What is binge eating disorder?
Recurrent episodes of over-eating in the absence of weight control behaviours = strong overlap with obesity = patients are often in their 40s and 25% are male
ED (Eating Disorder) patients commonly move between diagnostic criteria e.g….
Many anorexia sufferers become bulimia sufferers with time whereas few bulimia sufferers become anorexia sufferers. There is also a lot of movement out of anorexia & bulimia into atypical EDs and then diagnostic escape!
Anorexia and bulimia sufferers often share 4 demographic characteristics. They are…
Mostly female (90%), adolescents (young adults for bulimia), predominantly from western societies and mainly caucasian
Name 3 demographic differences between anorexia and bulimia
1) A: possible excess in high social classes vs. B: even distribution across social class, 2) 0.7% vs. 1-2% prevalence, Possible vs. likely increase in incidence across the generations (= secular change)
The ideal girl, as measured in terms of front cover models, had a BMI (weight/height squared) of ___ in 1991 where…
15.6 where < 18.5 is underweight and > 25 is overweight (Nichter, 1991)
There has been a change in the “thin ideal” across the generations. Wiseman (1992) found that Playboy models had an average weight of __% of the population average in 1989 compared to __% in 1959
82.5% from 91%
Sypeck (2003) found that the number of glamour magazine front covers displaying ___ ___ ___ increased a lot from 1985 to 2000
Full body shots
The shift in ED onset from adolescence to adulthood may reflect…
The inclusion of older women who conform to the thin ideal in TV programmes e.g. Desperate Housewives & Sex in the City
The much higher incidence rate of EDs amongst females relative to males may reflect the finding that…The gender drive for muscle vs. fat may be a confounding variable here
Females believe that their current weight is much greater than 1) what they believe males would find most attractive, 2) what they deem most attractive & 3) their ideal weight…in that order. In contrast, males believe that their current, ideal & most attractive weight are the same, though what they believe females would deem most attractive is a little lower
Do EDs originate with health conscious behaviours in adolescence?
Yes they may: 50% of girls begin dieting between the ages of 8 and 11 and 42% of girls diet because they “feel fat”
A problem with questionnaires on dieting is the…
Definition of dieting which may include items all the way from cutting down on food intake to eating more healthily
Glamour models, Playboy models and Sex in the City suggest that EDs are culture-bound. Give 3 pieces of evidence which differentiate between anorexia and bulimia in answering this question
1) There have been secular (generational) increases in BN but not in AN, 2) AN (not linked to the thin ideal) but not BN has occurred in other historical contexts & 3) AN (not linked to the thin ideal) occurs in non-western cultures but whether BN does depends on that culture’s exposure to western TV
What do the 3 pieces of evidence re: AN vs. BN and whether they are culture-bound suggest?
That BN is linked to the thin ideal and is therefore culture bound. AN is not linked to the thin ideal and hence is not culture bound
Can the thin ideal completely explain the incidence of EDs? Why? (3 reasons)
No, because 1) whilst the environmental pressure for thinness is immense, EDs are rare, suggesting that IDs in psychobiological vulnerability to pressures play a role & 2) There are historical & non-western incidents of AN where thinness was/is not prized & 3) EDs show such stereotypic symptoms, age-of-onset & developmental trajectories
Name 2 challenges which psychobiological research into EDs faces
1) Psychobiological factors may only be state factors (i.e. associated with the ED rather than being present prior to symptom onset) e.g. products of starvation & 2) or state factors of comorbid anxiety or depression. Conc) Correlates may not be causal
The following hormones regulate body weight and appetite: grehlin, peptide YY, cholecystokinin (CCK), leptin & insulin. Group them into 3 categories
1) Short duration, meal-related satiety signals (act rapidly to initiate/terminate meals): grehlin, CCK. 2) Intermediate acting hormones which inhibit eating between meals: peptide YY. 2) LT regulators which act slowly to decrease appetite & keep body fat stores stable: leptin & insulin
Acute ANervosa is characterised by hypo___
Hypoleptinaemia i.e. a lack of leptin = heightened appetite = binge eating
Leptin depletion is a ___ factor not a ___ factor of anorexia which contributes to clinical physical symptoms such as…(2 things)
State factor, not a trait factor. 1) Amenorrhea (missing menstrual cycles) & 2) Decreased bone mineral density
Whilst low levels of leptin may simply be a state factor (consequence of anorexia), they may still serve to perpetuate or maintain the disorder by encouraging…(2 related things)
Excessive exercise and physical restlessness
It has been found that restricting the feeding schedules of mice whilst giving them free access to a running wheel causes them to…(2 things)
Run 10km/day & run themselves to death. In fact, giving them access to a running wheel causes them to consume even less of the food = a vicious cycle
As far as leptin is concerned, it is believed that…(link food restriction, physical hyperactivity, decreases in leptin & prevention of further weight gain)
Food restriction causes 1) physical hyperactivity & 2) decreases in leptin. 1) & 2) encourage each other. All 3 factors prevent further weight gain
Rats administered with leptin make ___ revolutions of the running wheel
Fewer
Hormones have their effect by influencing the ___. Leptin seems to ___ on recovery
Hypothalamus. Normalise
Serotonin is implicated in EDs. It is argued that ___ disturbance of 5HT transmission is…
Premorbid (prior to experiencing the disorder). Modulated by restricted eating or binging, which are interpreted as ways of correcting serotonin dysfunction
Serotonin dysfunction had been linked to 3 factors which are also important in EDs. What are these?
1) Abnormal mood & emotional processing, 2) Appetite dysregulation & 3) Impulsive/compulsive/obsessional behaviour
Psychological factors play a role in EDs. BN & AN patients have more -ve thoughts whilst a), b) & c), though the difference to normal controls is not significant for _ _ in c)
a) Eating a chocolate mint e.g. I have no self-control, b) Being weighed e.g. I’m getting fatter and fatter & c) Looking at themselves in the mirror. AN
EDs are characterised by biased cognitions but do these cognitive distortions affect perception or just memory?
Shafran (2002) asked Pps to adjust a projected life-size image of themselves so that it matched a) exactly what they saw in the mirror & b) what they would like to see in the mirror. ED patients overestimated their own weight (by 17%) & were less satisfied with it
Shafran (2007) used the visual dot probe task to measure ED patients’ biased attention towards/away from different stimuli. What was found?
Compared to controls, patients showed an attentional bias away from (avoidance of) +ve eating stimuli & a bias towards -ve eating stimuli & neutral weight stimuli (e.g. weighing scales)
Shafran (2007) also tested anxiety patients - why?
To ensure that the ED patients’ results could not simply be explained in terms of comorbid anxiety
How do we know whether attentional, thought-based and perceptual biases are a cause or effect of EDs?
Pps who are semi-starved shows signs of fixating on food in daily life to a much greater extent than prior to semi-starvation (Kalm, 2005)
Why was the semi-starvation study carried out? How much weight did the average Pp lose? What other symptoms did semi-starvation induce?
To investigate the problem of re-feeding civilians after they had been semi-starved during the war. 25%. Extreme weakness, irritability, fatigue & amnesia
___ism has been linked to AN. What is ___ism?
Perfectionism = compulsive striving towards unattainable goals, having impossibly high standards & basing your own worth entirely on achievement
___ive traits are thought to be associated with BN. Does the evidence support this view?
Impulsive traits. Yes in self-report and by the finding that BN patients show more self-harm & alcohol & substance abuse. No in terms of their performance on neuropsychological tests of cognitive control
What two pieces of evidence suggest that AN/BN are associated with altered functioning of the reward system?
1) EDs share clinical characteristics with & have high incidence rates of substance abuse & addition, 2) Dopamine anomalies are implicated in EDs
Distinguish between the malfunctioning reward systems of AN patients & BN patients. Individuals with BN may be…(a personality trait), where as individuals with AN may be…
BN: hedonic (they find food rewarding) which would explain approach behaviours (e.g. overeating). AN: anhedonic (find food unrewarding) which would explain compensatory behaviours (e.g. excessive exercise). It has been found that the more excessively AN patients exercise the more anhedonic they tend to be (Davis, 2002)
What 2 pieces of evidence does Wagner (2007) present to suggest that at the neural level AN patients show abnormal reward processing?
1) AN Pps showed reduced activity in the insula, ACC & striatal regions during blind administration of sucrose vs. water. 2) Pleasantness ratings are +vely correlated with ACC, striatum & insula activity in controls but not in AN
What 3 mechanisms are proposed by Fairburn (1998) to account for the “need to control” in reinforcing self-worth in EDs?
1) Dietary restriction enhances their sense of being in control, 2) Starvation reinforces dietary restrictions by threatening perceived self-control & 3) Avoidance of mirror checking results in the absence of feedback, perceived failure of control & more dieting
At the same time the more you lose weight the more difficult it becomes to lose more weight & so to reassert/demonstrate self-control. Therefore, to treat EDs we must break…& boost…
The link between perceived self-worth & amount of self-control. Self-worth
