Nicotine Addiction: GENETICS

Question 1

(Essay Only) How does the behaviour of Smoking initiate according to the function of genes? (3 points)

Answer 1

• Some people inherit a genetic vulnerability to start smoking & ultimately develop an addiction
• One candidate gene for smoking is the A1DRD2 variation
• Seems to cause defective & insufficient dopamine receptors in the brain’s reward circuitry, meaning individuals can’t produce pleasure naturally & may engage in smoking behaviours to raise dopamine to optimal levels

Question 2

How is Smoking maintained - IN SHORT (2 points)

Answer 2

• As nicotine is a stimulant it increases the production & activity of dopamine in the brain
• We tend to find this very rewarding, which leads to repetition of the behaviour

Question 3

How is Smoking maintained according to dopamine activity (5 points)

Answer 3

1 - Nicotine stimulates specific receptors - acetylcholine receptors (NaCR)

2 - This causes rise in dopamine activity in the VTA : critical area in the brain’s reward circuitry highly populated with NaCR = rewarding sensation

3 - VTA activity caused by nicotine is then projected to the nucleas accumbens = producer of dopamine located deep in the mesolimbic dopamine pathway

4 - Nucleas accumbens = priamry reward centre in the brain, and as dopamine use rises, users evaluate it as very pleasurable - compelling more use

5 - (ADDITIONAL HIT) At the same time, the nucleas accumbens encouraged to release more dopamine as nicotine stimulates endorphins that reduce GABA - correlated with further rises in dopamine

Question 4

How do Smokers relapse according to the process of downregulation (4 points)

Answer 4

• Nicotine triggers dopamine firing in the mesolimbic pathway = a reward or a ‘kick’
• With LT use, the Nicotine Regulation Model suggests the smokers ‘reward system’ becomes less active (downregulation) i.e. specific acetylcholine receptors become inacitve = anxiety
• To avoid this, smokers continue to maintain certain level of nicotine in their bodies to avoid unpleasant side effects
• As a result of this, an increased amount of nicotine is needed to achieve the same initial ‘kick’

Question 5

(Strength) Outline Paterson et al’s (2002) study (3 points)

Answer 5

• Researched the use of Gamma-vinyl GABA, which **redueces the surge of dopamine in the nucleas accumbens
• Effectively reduces addictive properties of nicotine, without major side effects
• Illustrates the involvement of dopamine with smoking addiction

Question 6

(Strength) What is the Practical Application of the biochemical explanation? (2 points)

Answer 6

• Delivering therapeutic doses of nicotine in the early stages of smoking
• The use of inhalers has been shown to keep 28% of the treatment group off smoking for 12 months

Question 7

(Weakness) Outline Nerin & Jane’s (2007) study (3 points)

Answer 7

• Showed ‘Beta bias’
• Argued onset of smoking addiction has significantly different between sexes i.e. women typically start smoking much later
• The biological reasoning for this is ignored

Question 8

(Weakness) Explain how the account neglects the role of NURTURE (2 points)

Answer 8

• Peer approval for smoking can create reinforcement (that activates dopamine) - little to do with the biological action of nicotine
• Perhaps nicotine & peer approval collectively account for rises in dopamine