Explanations of anorexia nervosa

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explanations of anorexia

. The biological explanations of anorexia are interesting but inconclusive. One attempt hasfocused on genetic factors - with ambiguous results. Holland et al. (1988) found thataround 56% of identical (MZ) twins are concordant for thedisorder, compared with 5%for DZ twins; Hsu (1990), after an extensive literature review, found a 47% concordancerate for (DZ) twins and 10% rate for non-identical (DZ) twins. However, the fact thatrelatives of anorexics run a higher risk than the general population of also becominganorexic does not, according to Frude (1998), suggest that a firm genetic link for anorexiacan be inferred. Instead, the shared family environment may account for these findings.MZ twins are often discordant for the condition & genetic explanations offer no practical

possibilities for treatment.

Kaye et al. (1988) suggests that a dysfunctioning hypothalmus may offer a partial

explanation for anorexia. The lateral hypothalamus (LH) produces hunger & the

ventromedial hypothalamus (VH) depresses hunger. The hypothalamus regulates hungersensation and instigates the eating impulse, however, animal studies have shown thatwhen the hypothalamus is in some way damaged, this process is disrupted. One theory isthat a reduction of a neurotransmitter called norepinephrine (epinephrine is a synonym ofadrenalin) can disturb the operation of the hypothalamus and lead to anorexia: drugswhich increase norepinephrine levels have been reported as helpful in treating anorexia

(Frude 1998). However, Doers et al. (1980) suggest that disturbances in the

hypothalamus might be the result of self-starvation and not the cause of it, for instance,hormonal abnormalities in the hypothalamus disappear after weight gain. Also, Davisonand Neale (1998) point out that anorexic patients starve themselves despite still feelinghungry, however, the animals with hypothalamic disturbances did not exhibit behaviourwhich suggested hunger, rather they became indifferent to food. They also point out that

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the hypothalamic explanation cannot account for the anorexic's derogatory self-image.Kaye et al. (1993) has suggested that some of the symptoms of anorexia, such as anxiety,obsessional and compulsive behaviour can be linked to an abnormality in anotherneurotransmitter - serotonin. Zinc deficiencies are also a common feature of anorexicpatients, and it has been suggested that symptoms of anorexia, such as weight loss anddepression, could be due to a low level of zinc in the body (Bakan et al., 1993). Someresearch suggests that endogenous opioids are also released during periods of starvation.The release of opioid chemicals may produce a feeling of elation and ...

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