Explanations for Nicotine Addiction
THE DOPAMINE EXPLANATION
It is thought that smoking/ingestion of nicotine can produce dopamine activity to spike, especially
through the ‘reward system’ pathways of the brain.
The Ventral Tegmental Area (VTA) is an area of the brain filled with dopamine-specialist neurons. This
area is associated with feelings of euphoria and can be triggered through smoking cigarettes,
producing a feeling of pleasure.
The explanation is that repeated usage of this system can lead to desensitisation, which then leads to
greater doses of drugs and eventually addiction
THE ROLE OF DOPAMINE
1. Nicotine stimulates specific acetylcholine (nicotinic acetylcholine receptors - NAcR) receptors
which increase alertness, memory function and learning.
2. This action causes a rise in dopamine activity in the ventral tegmental area (VTA): a critical
area in the brain's reward circuitry which is highly populated with NAcR. This is seen to
underline rewarding sensations linked to smoking.
3. The VTA activity caused by nicotine is then projected to the nucleus accumbens, a producer
of dopamine that is located deep in the mesolimbic dopamine pathway.
4. The nucleus accumbens is the primary reward centre in the brain and with increased activity
dopamine rises causing users to evaluate ‘smoking’ as very pleasurable, compelling further
use.
5. Furthermore, the nucleus accumbens is encouraged to release more dopamine as nicotine
also stimulates endorphins that reduce GABA activity in the nucleus accumbens. A decrease
in GABA function correlates with further rises in dopamine (as GABA usually suppresses
dopamine). More dopamine forces smokers to engage with further use.
NICOTINE REGULATION MODEL
Another part of the biological approach is the Nicotine Regulation Model.
After a period without a cigarette, for example while the smoker sleeps, the downregulated nicotine
acetylcholine receptors become upregulated.
They start to work again making the brain far more sensitive to the effects of acetylcholine in the
synapse.
This produces feelings of anxiety, agitation and restlessness. Dopamine levels will also have
dropped. These feelings are unpleasant.
The smoker can very quickly remove these unpleasant symptoms by smoking a cigarette, releasing
nicotine into the synaptic cleft and shutting down the nicotine acetylcholine receptors!
Most smokers will tell you that the first cigarette of the day is the most pleasurable. It will of course,
also result in the release of dopamine.
Sensitive receptors lead to more pleasure.
EVALUATIONS OF THE BIOLOGICAL EXPLANATION
Not everyone becomes addicted to smoking when they try it, so there must be other factors involved
that mediate the chances of repeating the behaviour and becoming addicted. Therefore, it could be
argued that there is low explanatory power with this explanation.
The counter to this argument is that there is an explanation that genetic vulnerabilities expose
individuals to higher feelings of pleasure in these substances, increasing the chances of them
becoming addicted.
Biologically reductionist, as it ignores social, psychological and cultural factors, means it is
theoretically parochial (narrow-minded).
Deterministic - its socially sensitive, suggests people have a predisposition for nicotine addiction
THE DOPAMINE EXPLANATION
It is thought that smoking/ingestion of nicotine can produce dopamine activity to spike, especially
through the ‘reward system’ pathways of the brain.
The Ventral Tegmental Area (VTA) is an area of the brain filled with dopamine-specialist neurons. This
area is associated with feelings of euphoria and can be triggered through smoking cigarettes,
producing a feeling of pleasure.
The explanation is that repeated usage of this system can lead to desensitisation, which then leads to
greater doses of drugs and eventually addiction
THE ROLE OF DOPAMINE
1. Nicotine stimulates specific acetylcholine (nicotinic acetylcholine receptors - NAcR) receptors
which increase alertness, memory function and learning.
2. This action causes a rise in dopamine activity in the ventral tegmental area (VTA): a critical
area in the brain's reward circuitry which is highly populated with NAcR. This is seen to
underline rewarding sensations linked to smoking.
3. The VTA activity caused by nicotine is then projected to the nucleus accumbens, a producer
of dopamine that is located deep in the mesolimbic dopamine pathway.
4. The nucleus accumbens is the primary reward centre in the brain and with increased activity
dopamine rises causing users to evaluate ‘smoking’ as very pleasurable, compelling further
use.
5. Furthermore, the nucleus accumbens is encouraged to release more dopamine as nicotine
also stimulates endorphins that reduce GABA activity in the nucleus accumbens. A decrease
in GABA function correlates with further rises in dopamine (as GABA usually suppresses
dopamine). More dopamine forces smokers to engage with further use.
NICOTINE REGULATION MODEL
Another part of the biological approach is the Nicotine Regulation Model.
After a period without a cigarette, for example while the smoker sleeps, the downregulated nicotine
acetylcholine receptors become upregulated.
They start to work again making the brain far more sensitive to the effects of acetylcholine in the
synapse.
This produces feelings of anxiety, agitation and restlessness. Dopamine levels will also have
dropped. These feelings are unpleasant.
The smoker can very quickly remove these unpleasant symptoms by smoking a cigarette, releasing
nicotine into the synaptic cleft and shutting down the nicotine acetylcholine receptors!
Most smokers will tell you that the first cigarette of the day is the most pleasurable. It will of course,
also result in the release of dopamine.
Sensitive receptors lead to more pleasure.
EVALUATIONS OF THE BIOLOGICAL EXPLANATION
Not everyone becomes addicted to smoking when they try it, so there must be other factors involved
that mediate the chances of repeating the behaviour and becoming addicted. Therefore, it could be
argued that there is low explanatory power with this explanation.
The counter to this argument is that there is an explanation that genetic vulnerabilities expose
individuals to higher feelings of pleasure in these substances, increasing the chances of them
becoming addicted.
Biologically reductionist, as it ignores social, psychological and cultural factors, means it is
theoretically parochial (narrow-minded).
Deterministic - its socially sensitive, suggests people have a predisposition for nicotine addiction
