HEALTH biological explanation for heroin addiction

Question 1

A01 points for paragraph 1

Answer 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 heroin can directly cause huge amounts of dopamine to be released.
• 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

Answer 2

SUPPORTING EVIDENCE : Vereczkei (2013)
found that the A1 variant of the DRD2 gene was overexpressed in 303 Hungarian heroin addicts compared to 555 controls by analysing their genotype data using cheek swabs. the use of a control group allowed Vereczkei to make comparisons between heroin addicts and non-addicts.
HOWEVER, despite using a large sample including a control group, all the addicts tested were Hungarian and the findings may not be representative of heroin addicts in other cultures

Question 3

A03 negative point for paragraph 1

Answer 3

REFUTING EVIDENCE : Friedman et al. (1985)
used a structured interview on 157 teenagers to investigate smoking initiation and found that peer encouragement and exposure to smoking peers were significant risk factors associated with onset and continued smoking. heroin use may also be learned in the same way from peers rather than die to genes such as the DRD2 A1 variant.
HOWEVER, this research did not directly investigate heroin use, and therefore extrapolation is limited.

Question 4

A01 points for paragraph 2

Answer 4

• the DRRD2 gene is viewed as a ‘pleasure-seeking’ gene and codes for the number of D2 dopamine receptors available in the mesolimbic dopamine system.
• individuals with the A1 variant 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 : use of saliva swabs
it is possible to pinpoint the A1 variant of the DRD2 gene using scientific measurements such as saliva and blood tests. these measures 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 : SLT
the SLT would suggest that heroin addiction comes from the imitation of role models rather than due to the A1 variant. it challenges the genetic explanation and could provide a more plausible explanation for heroin addiction.

Question 7

A01 points for paragraph 3

Answer 7

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

Question 8

A03 positive point for paragraph 3

Answer 8

USEFUL APPLICATION : identifying individuals at risk
potential screening for the A1 variant could help identify individuals who may be more susceptible to drug use. it would allow health professionals to moniter these individuals and help put preventative measures in place to minimise the likelihood of them using heroin.

Question 9

A03 negative point for paragraph 3

Answer 9

NATURE NURTURE DEBATE : nature
a genetic explanation argues that heroin addiction is due to a specific gene which programs a person to have dopamine deficiency (nature). it does not acknowledge that often heroin addiction is due to a genetic predisposition being triggered by environmental stressors (nurture).

Question 10

A03 positive point for conclusion

Answer 10

REDUCTIONIST : pinpoints a specific gene
is adopts a reductionist approach to studying heroin addiction and isolates the A1 variant. this makes it easier for us to study causes for heroin addiction in a more scientific way.

Question 11

A03 negative point for conclusion

Answer 11

REDUCTIONIST : ignores social factors
by isolating the A1 variant as a cause for heroin addiction we are ignoring other factors affecting heroin use such as the presence of other users at a party or increased stress leading to more drug use therefore making the explanation reductionist and simplistic.