biological explanations

Question 1

what did volkow find

Answer 1

those who liked exposure to Ritual had fewer dopamine receptors than those who hated it

Question 2

What has been found from twin studies

Answer 2

a higher concordance rate in MZ twins than DZ twins

Question 3

what did comings find

Answer 3

48% of smokers had the A1 variant compared to 25% of the general population

Question 4

what is a problem with the genetic explanation

Answer 4

It is reductionist as not all addicts have the a1 variant so it cannot be the only cause

Question 5

what did harrison find

Answer 5

rats who receive nicotine need less electricity to receive the same simulation/reward

Question 6

what did Olds and Milner find

Answer 6

rats would press a lever for a reward of mild simulation in preference to other rewards

Question 7

outline the role of neurotransmitters in addiction

Answer 7

addictive drugs overstimulate the reward pathway (limbic system) by flooding it with dopamine (from the ventral segmental area), this gives a sense of pleasure to the nucleus accumbent

the addiction is maintained as the structure and function of the reward system neutrons are altered. Receptors are desensitised and become tolerant to the effects of dopamine so more is needed for the same reward.

Relapse occurs as the VTA and NA pathways are linked to areas associated with memories so they are sensitive to reminders of past highs, also the prefrontal cortex is damaged and nor as effective at making decisions

Question 8

outline the role of genetics in addiction

Answer 8

Those with the a1 variant of the d2 receptor have fewer receptors so need more dopamine to compensate for this