Eating Disorders Flashcards
What is the criteria for anorexia nervosa? What are the two types? Why was amenorrhoea removed in the DSM-5?
- Restriction of energy intake relative to requirements leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. DSM-5 more reliant on BMI than DSM-IV. In adults, severity is indicated by: Mild; BMI
What is the criteria for bulimia nervosa?
- Characterised by uncontrollable binge eating, and efforts to prevent resulting weight gain by using inappropriate behaviours such as self-induced vomiting and excessive exercise. - Compared to DSM-IV, criteria for BN in DSM-V have been relatively relaxed. Binge eating and purging now have to occur on average once a week (compared to twice a week) over a 3-month period. This change was made after research showed that people with sub-threshold bulimia nervosa were remarkably similar to those who had the full syndrome. - The difference between binge-eating/purging anorexia nervosa and bulimia nervosa is weight. By definition, AN sufferers are severely underweight, those with BN do not have to be. As a result, diagnostically, AN is a more severe diagnosis than BN due to a far greater rate of mortality.
What is the criteria for binge eating disorder?
- A new addition to DSM-5 (in DSM-IV was provisional in order to encourage research- which subsequently suggested that it be considered a distinct clinical disorder in its own right). - Despite sharing some clinical features with BN, there is an important difference: o After a binge (comparable to those in BN) the person with BED does not engage in any form of inappropriate “compensatory” behaviour. There is also much less dietary restraint that is typical of BN or AN. o Unsurprisingly, BED is associated with being overweight or even obese.
Outline age of onset and gender differences in EDs.
- Despite only recent interest in EDs, there have been accounts of pathological eating patterns dating back centuries. AN or BN do not occur in appreciable numbers before adolescence. It has, however, been recorded in children as young as 7- especially AN. For AN, risk is highest in 15-19 year olds, and for BN is highest between 20-24. Most patients with BED are older, between 30 and 50 years of age. In the past, the gender ratio was as high as 10:1 (females: males), however recent estimates suggest it is more like 3:1. This reflects the idea that men have been under-diagnosed in the past due to the stereotype that EDs are female disorders. It is also the result of gender bias in the DSM criteria. These emphasise the type of weight and shape concerns (desire to be thin) and methods of weight control (dieting). For men, body dissatisfaction often involves wishing to be more muscular, and weight control is more likely to include over-exercising. - One established risk factor for ED in men is homosexuality. Gay and bisexual men have higher rates of ED as they (like heterosexual men) value youth and attractiveness in their partner, meaning that gay men (like women) seek to be sexually attractive to men, body dissatisfaction may be more of an issue for them.
What are the medical complications of EDs?
- Mortality rate for females between 15 and 24 is 12x higher in those with anorexia nervosa, compared to average. - ~3% of AN patients die from the consequences of self-imposed starvation. - When suffering from malnutrition, AN patients have thinning hair and brittle nails, very dry skin, lanugo grows on their bodies, and they become jaundiced. Often have difficulty coping with cold temperatures, and have chronically low blood pressure causing fatigue, weakness, and fainting. While most effects subside with weight gain, AN may cause a permanent risk for osteoporosis in later life- failure to eat healthily in the period where peak bone density is achieved may result in brittle and fragile bones forever.
Outline the general course and outcome for EDs.
- After medical complications, the second most common cause of death in AN sufferers is suicide. - 1/5 deaths in AN individuals is as a result of suicide. 50x greater than in the general population. - 3-23% of patients will make an attempt. - Patients who lose their ability to maintain an “emotionally protective” low body weight are at particularly high risk. - In a follow up study after 21 years, Lowe et al (2001) found that 16% of patients (all women) were no longer alive due to complications from starvation or suicide. 10% still suffered, and a further 21% had partially recovered. Positively, however, 51% of patients had fully recovered. - Outcomes for BN are quite good. 70% of diagnosed women will be in remission and no longer qualify for diagnosis at a 11-12 year follow-up (Fichter & Quadflieg, 2007). The remaining 30%, however, will still continue to have significant eating difficulties. - Binge-eating prognosis is also quite good with a 66% rate of clinical remission. Important to remember that the idea of recovery is relative. While these people may not meet the criteria for diagnosis, they may still have issues with food and body image.
What is the issue of diagnostic crossover in EDs?
EDs differ from other disorders in that there is lots of diagnostic crossover. Eddy et al. (2008) report that the majority of women in their study experienced diagnostic crossover- bidirectional transitions between the two subtypes of anorexia nervosa were especially common. Shifts from binge-purging AN to BN occurred in about 1/3 of patients. There were no cases of transition from restricting AN to BN. This is because if a binge-purging AN patient gains weight, their diagnosis will be changed to BN. These women remained vulnerable to relapsing back to AN. Only a minority cross from BN to AN (14%). Binge-eating and AN experience little crossover.
How common is comorbidity in EDs?
Comorbidity is the rule, rather than the exception. 68% of AN patients, 63% of BN patients, and almost 50% of BED patients are diagnosed with depression (Hudson et al. 2007). OCD is often found in AN and BN patients (Milos et al. 2002). Also a frequent co-occurrence of substance-abuse disorders in the binge-purging AN subtype as well as BN. Cluster C (anxious-avoidant) is likely to be associated with restricting-type AN, while Cluster B (histrionic, dramatic, emotional) are likely to be associated with binge-purging AN and BN, especially BPD. More than 1/3 of patients engage in self-harming behaviours that are symptomatic of BPD.
Outline and evaluate the role of genetics in EDs.
The tendency to develop an ED runs in families (Wade, 2010). In one large study, the risk of AN for the relatives of individuals with AN was 11.4x greater than for the relatives of healthy controls. In BN, the risk is 3.7x higher (Strober et al., 2000). There is also a higher risk of other disorders in the relatives of those with an ED. E.g., MDD, alcohol/drug dependence, and OCD (Lilenfeld et al. 1998). However, need to disentangle genes and environment. Only one adoption study (Klump et al. 2009) has been conducted so far, which suggests that disordered eating was between 50%-82% heritable for female-female twins, with shared environmental factors not having a significant effect. However, these findings need to be replicated. Very inconsistent findings when attempting to implicate candidate genes in EDs. Grice et al. (2002) linked chromosome 1 to susceptibility to rAN. However, a recent study failed to find any links between 182 different candidate genes and various aspects of eating disorders such as lowest BMI, drive for thinness, or body dissatisfaction (Root et al., 2011). Serotonin regulation genes have been implicated in EDs (Wade, 2010). This makes sense as serotonin plays a role in the regulation of eating behaviour. Since it also regulates mood, it is interesting to note that mood disorders and eating disorders often cluster together in families (Halmi, 2010).
Outline and evaluate the role of brain abnormalities in EDs.
The hypothalamus has an important role in eating. When the lateral hypothalamus is electrically stimulated in animals, it will start to eat, even when full. However, there is no good evidence that the hypothalamus has a role in eating disorders. However, damage to the frontal and temporal lobe has been linked to the development of AN in some cases, and BN in others. The temporal lobe is linked to body image perception. The orbitofrontal cortex also plays a role in monitoring the pleasant ness of stimuli such as smell and taste (van Kuyck et al, 2009).
What are the role of set-points in EDs?
Our body tends to resist marked variation from some sort of biologically set point or weight that our individual bodies try to “defend” (Garner, 1997). Those aiming to lose body mass attempt to do so in the face of physiological opposition. One of these is hunger. Far from having little or no appetite, patients with AN may think about food constantly and make intense efforts to suppress their increasing hunger. Accordingly, chronic dieting may well enhance the likelihood that person will encounter periods of seemingly irresistible impulses to gorge on large amounts of high-calorie food.
Outline the role of serotonin in eating disorders.
Serotonin is implicated in obsessionality, mood disorders, and impulsivity. It also modulates appetite and feeding behaviour. Many patients respond well to antidepressants that target serotonin, it is logical to believe that EDs involve disruption to the serotonergic system. People with AN have low levels of 5-HIAA, which is a major metabolite of serotonin, possibly because they are eating so little. Levels of 5-HIAA are normal in BN individuals. However, after recovery, both groups of patients have higher levels of 5-HIAA than control woman and what they did when they were ill. Remember that serotonin does not work in isolation. A change in the serotonin system will have implications for other neurotransmitter systems too (e.g., dopamine, norepinephrine).
Outline the role of family influence in EDs.
There is increasing pressure for thinness and the media bombards young, impressionable people with images of unrealistically thin models. Social pressures towards thinness may be particularly powerful in higher socioeconomic backgrounds, from which a majority of girls and women with AN seem to come. In Fiji, in the 1990s, many Fijians (especially women) were overweight compared to their Western counterparts. Fatness in Fiji was associated with strength, ability to work, kindness and generosity. Thinness was thought to reflect being sickly, incompetent, or receiving poor treatment. Dieting was viewed as offensive, and fatness was preferred. However, after TV arrived, the cultural climate changed. Western TV shows caused women to begin to express concerns about their weight and dislike of their bodies. Family Influences More than 1/3 of AN patients reported that family dysfunction was a factor that contributed to the development of their eating disorder. They perceive their families as more rigid, less cohesive, with poor communication than healthy controls. In addition, many parents of ED patients have a long-standing preoccupation with thinness, dieting, and food physical appearance (Garner & Garfinkel, 1997). Like their children, they have perfectionistic tendencies (Woodside et al., 2002). In BN, there are particular risk factors such as high parental expectations, other family members’ dieting, and degree of critical comments from other family members about shape, weight, or eating. In college-age women, the strongest predictor of BN symptoms was the extent to which family members made disparaging comments about the woman’s appearance and focused on her need to diet (Crowther et al., 2002). However, the causal connection, if any, might go in the other direction. I.e., having an eating disorder is likely to affect family functioning in a negative way.
Outline the individual risk factors for EDs (gender, thin ideals, perfectionism, negative body image, dieting, negative emotionality, childhood sexual abuse)
Gender Being female is a strong risk factor for developing EDs, particularly AN and BN. The greatest risk period for this is in adolescence. BED does not typically follow this pattern, and typically develops after adolescence. It is also more likely to be found in males as well as females. In men, sexual orientation is a risk factor. This may be because gay and bisexual men are trying to be attractive to men, who typically place great emphasis on physical appearance. Being in a same-sex relationship, however, appears to moderate this risk as individuals feel less pressure. Internalising the “Thin Ideal” Internalising the thin idea may be an early component of the causal chain that culminates in disordered eating (McKnight Investigators, 2003). Perfectionism Perfectionism is an important risk factor for EDs (Bruch, 1973). This is because people who are perfectionist may be much more likely to subscribe to the thin ideal and relentlessly pursue the “perfect body”. Perfectionism may help maintain bulimic pathology through the rigid adherence to binge/purge cycles (Fairburn et al., 1997). Halmi et al. (2000) found that women with AN scored higher on perfectionism regardless of which type of AN they had. A large proportion of BN patients also demonstrate long-standing patterns of perfectionism (Anderluh et al. 2003). Perfectionism is not the result of EDs either; this trait remains after AN recovery, for example (Bardone-Cone et al. 2007). Negative Body Image Sociocultural pressure to be thin results in highly intrusive and pervasive perceptual biases regarding how “far” they are (e.g. Fallon & Rozin, 1985). Women also feel evaluated by their female peers, who they feel even more stringent standards of weight and shape than they do themselves. Dieting Nearly all instances of EDs begin with the “normal” dieting that is routine in our culture. Estimated that at any one time, 39% of women and 21% of men are trying to lose weight (Hill, 2002).
Outline and evaluate the role of medications in treating AN.
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