Biological Explanations for AN Flashcards
What support is there for a genetic basis of AN?
Holland 1988: concordance MZ 56%, DZ 7%, longitudinal natural study but genes aren’t the only factor or MZ would be 100%
What IDA comments can be made about the genetic explanation of AN?
nature vs nurture, anorexia isn’t caused by genes alone, Gorwood: to identify causes, need subtypes of AN, genes cant explain increase in AN in past 30 years
How is serotonin related to AN?
reduction in serotonin receptors, dysfunction of system which is part of larger neurotransmitter system of hypothalamus
What IDA points can be made about neural explanations of AN?
diathesis stress model may be more appropriate: biological predisposition but AN triggers by stressors
What is the evidence from animals on the hypothalamus?
Garfinkel and Garner 1992: damage to parts of the hypothalamus can causes animal to starve itself to death, little evidence in humans
How is the hypothalamus linked to AN?
malfunctioning of ‘hunger centres’ in hypothalamus, AN cause malfunction or malfunction cause AN?
What is the evidence for differences in serotonin in people with AN?
Frank 2002: PET scans = fewer serotonin receptors in AN
Kaye 2005: recovered AN still have changed brain (weight gain doesn’t alter serotonin levels)
What is the Reproduction Suppression Model?
reproduction delayed in stressful environment by fasting which stops menstruation
What is the Adapted to Flee Famine Hypothesis?
anorexics have high levels of activity which would be beneficial for moving to next food source
What supporting evidence is their for the Reproduction Suppression Model?
Crisp 1980: loss of body weight of AN = postpones/stops menstruation
What supporting evidence is their for the Adapted to Flee Famine Hypothesis?
Guisinger 2003: anorexics are restless and have high levels of activity unlike other responses to starvation
What IDA points can be made about the evolutionary explanations of AN?
accounts for gender differences (men not subject to reproduction suppression), accounts for higher rates of AN in immigrants (more energy to flee)
What conclusion did Kaye come to about AN?
An has pre existing excess of serotonin in relation to receptors, drives the neuronal activity, creates anxiety, individual is primed to associate restrained eating with respite from anxiety (not eating lowers serotonin)
