Addiction- brain chem explanation for nicotine addiction

Question 1

What are the two parts of the neurochemistry explanation

Answer 1

Smoking initiation- genes and dopamine function

Smoking maintenance- increased dopamine activity

Question 2

What gene is involved with smoking addiction

Answer 2

A1DRD2 candidate gene

Question 3

What does the A1DRD2 candidate gene cause/do

Answer 3

Seems to code for defective and insufficient dopamine receptors in the brain’s reward circuitry, which means they can not produce pleasure naturally

Question 4

Is nicotine a stimulant or depressant

Answer 4

Stimulant

Question 5

What does a stimulant drug do

Answer 5

It increases the production and activity of dopamine in the brain.

Question 6

Why do stimulants lead to repetitive behaviour

Answer 6

Because we find the dopamine release rewarding

Question 7

What does nicotine stimulate

Answer 7

Specific acetylcholine (nicotinic acetylcholine receptors - NAcR) receptors

Question 8

What does the stimulation of NAcRs cause

Answer 8

Increased alertness, memory function and learning

Question 9

What is the ventral tegmental area

Answer 9

A critical area in the brain’s reward circuitry which is highly populated with NAcR.

Question 9

What does the stimulation of NAcRs do to dopamine

Answer 9

Causes a rise in dopamine activity in the ventral tegmental area (VTA):

Question 10

What gives nicotine a rewarding sensation

Answer 10

A rise of DA in the VTA

Question 11

What causes VTA activity

Answer 11

Nicotine

Question 12

Where is VTA activity (causes by nicotine) projected onto

Answer 12

The nucleus accumbens

Question 13

What is the nucleus accumbens

Answer 13

A producer of DA

Question 14

Where is the nucleus accumbens located

Answer 14

Deep in the mesolimbic pathway

Question 15

What is the primary reward centre in the brain

Answer 15

The nucleus accumbens

Question 16

What does increased activity in the nucleus accumbens lead to

Answer 16

DA rise

Question 17

What happens when smokers encounter a DA rise

Answer 17

Causes them to evaluate ‘smoking’ as very pleasurable, compelling further use.

Question 18

What does nicotine also stimulate besides DA

Answer 18

Endorphins

Question 19

What do endorphins do to GABA

Answer 19

Reduce its activity

Question 20

What does a decrease in GABA correlate with

Answer 20

A rise is DA

Question 21

What does more and more DA do to smokers

Answer 21

Forces them to engage with further use

Question 22

Who proposed the nicotine regulation model

Answer 22

Shachter

Question 23

With long term use, what does the NRM suggest

Answer 23

That the smokers ‘reward system’ becomes temporarily less active/sensitive (downregulation)

Question 24

What causes anxiety, sadness and lethargy in down regulation

Answer 24

Specific acetylcholine receptors become unavailable and inactive.

Question 25

How to smokers avoid the negative side effects

Answer 25

Smoke more to maintain a certain level of nicotine in their bodies

Question 26

What is smoking more to avoid unpleasant side effects and example of

Answer 26

Negative reinforcement

Question 26

Where does down regulation occur

Answer 26

Mesolimbic pathway

Question 26

With the down regulation in the mesolimbic pathway what is needed for the same initial ‘kick’

Answer 26

An increased amount of nicotine

Question 27

Why do LT smokers need more nicotine for the same initial ‘kick’

Answer 27

Receptors have been ground down

Question 28

What happens to the nicotinic receptors when an individual is smoking

Answer 28

They are desensitised
Cravings and withdrawal symptoms are held off

Question 29

What happens when smokers go without nicotine for a long period of time

Answer 29

Nicotine disappears from the body.
This allows more nicotine receptors to become functional again (upregulation).

Question 30

What is up regulation

Answer 30

Allowing more nicotine receptors to become functional again (upregulation).

Question 31

Evaluation, evidence
Paterson et al

Answer 31

P- Paterson et al. (2002) found support for the role of nicotine and dopamine through research with epilepsy drug (Gamma-vinyl GABA).

E-This drug reduces the surge of dopamine in the nucleus accumbens that occurs after nicotine. This effectively reduces the addictive properties of nicotine, without major side effects.

L- This suggests that nicotine is does activate DA and stopping this can help with cessation

Question 32

Evaluation, practical applications

Answer 32

P- The bio chem explanation as led to some useful practical applications

E-Delivering therapeutic doses of nicotine (without the undesirable parts of tobacco) in the early stages of stopping smoking.

E- This release of nicotine is absorbed much more slowly and steadily than in tobacco.

L- This implies the brain chem account of smoking addiction has the potential to help the 19% of smokers in the UK to ditch the habit.

Question 33

Evaluation, beta bias

Answer 33

P- However the explanation seems to suffer a beta bias

E-Nerin and Jane (2007) argue the onset of smoking addiction is significantly different between the sexes - i.e., women typically start smoking much later than men.

E- The biological reasoning for this is ignored.

L- This could imply the explanation suffers from an implicit gender bias

Question 34

Evaluation, neglects role of nurture

Answer 34

P-Neglects to consider the role of nurture.

E- Perhaps the rewarding qualities of nicotine are also gained through the environment - for example the peer acceptance and approval that have been shown to be positively reinforcing.

E- Research has shown that nicotine activates dopamine - but studies have also shown peer approval activates dopamine as well.

L- This could imply that the explanation could be more comprehensive if it takes into account nurturing influences of nicotine addiction

Question 35

Evaluation, scientific

Answer 35

P- Explanation can be praised for being scientific

E-The dopamine account uses both empirical and falsifiable methods to help identify the biochemical action of nicotine.

E- For instance, dopamine and NAcR can be objectively measured through cerebrospinal fluid (CSF), sophisticated PET scans as well as carefully examining urine for waste products.

L- This implies that the DA account for nicotine addiction is more trustworthy and reliable.