HEALTH biological explanation for addiction to alcohol DRD2 GENE(16 marks)

Question 1

A01 points for paragraph 1

Answer 1

1) dopamine is released in the mesolimbic dopamine system of the brain, to signal reward and pleasure. as well as several natural behaviours, chemicals such as alcohol can directly cause huge amounts of dopamine to be released.
2) dopamine binds with receptors in the brain; many D2 dopamine receptors are found in the Ventral Tegmental Area and the Nucleus Accumbens.

Question 2

A03 positive point for paragraph 1(and development point)

Answer 2

+ SUPPORTING : CONNOR ET AL (2002)
data from a clinical interview and alcohol dependence questionnaire found that adults with the A1 variant consumed more alcohol and had early onset problems related to alcohol therefore supporting the link between the A1 variant and increased alcohol consumption.

HOWEVER data was collected using self-report and may be affected by socially desirable responses if participants feel embarrassed about their alcohol intake. this would lower the validity of the findings.

Question 3

A03 negative point for paragraph 1

Answer 3

• REFUTING EVIDENCE : MUNDT ET AL (2012)
  Data from a survey found that adolescents’ friendship selection was influenced by similarity in alcohol consumption suggesting that friends are influential in shaping our drinking habits, suggests that alcohol use may be learned from our environment rather than due to genes such as DRD2.

FURTHERMORE Mundt’s data was collected longitudinally over a year which allows for any changes in alcohol use to be monitored increasing the validity of the findings.

Question 4

A02 points for paragraph 2

Answer 4

3) the DRD2 gene is viewed as a ‘pleasure-seeking’ gene and codes for the number of D2 dopamine receptors available in the mesolimbic dopamine system.
4) around 25% of individuals will have the A1 variant of the DRD2 gene and will have significantly fewer dopamine receptors, meaning they are unable to feel pleasure and satisfaction as well as someone with a higher number of dopamine receptors resulting in a ‘reward deficiency’.

Question 5

A03 positive point for paragraph 2

Answer 5

CREDIBILITY
it is possible to pinpoint the A1 variant of the DRD2 gene using scientific measurements such as saliva and blood tests which are objective and not affected by personal judgement therefore increasing the credibility of this explanation.

Question 6

A03 negative point for paragraph 2

Answer 6

ALTERNATIVE EXPLANATION
social learning theory would suggest that alcohol addiction comes from imitation of role models rather than due to the A1 variant; this challenges the genetic explanation and could provide a more plausible explanation.

Question 7

A01 points for paragraph 3

Answer 7

5) researchers speculate that people with this variation pursue pleasure-seeking behaviour such as using substances like alcohol to stimulate their existing dopamine receptors.
6) using alcohol gives them pleasure levels comparable to people with a standard number of receptors. however, this may lead to a dependence on alcohol to achieve this pleasure, leading to addiction.

Question 8

A03 positive point for paragraph 3

Answer 8

USEFUL APPLICATION
using dopamine receptor agonists to artificially stimulate dopamine receptors led to a reduction in alcohol consumption therefore supporting the idea that increasing dopamine through medication reduced the need to drink alcohol to compensate for the reward deficiency.

Question 9

A03 negative point for paragraph 3

Answer 9

NATURE/ NURTURE
a genetic explanation argues that alcohol addiction is due to a specific gene which programs a person to have a dopamine deficiency; this does not acknowledge that often alcohol addiction is due to a genetic predisposition being triggered by environmental stressors (nurture).

Question 10

A03 positive point for conclusion

Answer 10

REDUCTIONIST
by adopting a reductionist approach to studying alcohol addiction and isolating the A1 variant, this makes it easier for us to study causes for alcoholism in a more scientific way.

Question 11

A03 negative point for conclusion

Answer 11

REDUCTIONIST
DRD2 isolates the A1 variant as a cause for alcohol addiction and ignores other factors affecting alcohol consumption such as the presence of other drinkers at a party or increased stress leading to more drinking , making the explanation reductionist.