Addiction: Explanations for nicotine addiction Flashcards
Explanations for nicotine addiction: brain neurochemistry, including the role of dopamine, and learning theory as applied to smoking behaviour, including reference to cue reactivity.
What is the neurotransmitter for nicotine?
ACh
ACh plays a key role in all nervous system activity, which means there are ACh receptors on the surfaces of many ______ in the _________.
Neurons
Central nervous system
What is the specific receptor for nicotine?
nAChR
nACHR receptors are activated by ____/______.
ACh/nicotine
When nAChRs are activated by nicotine molecules, the neuron transmits _______.
Dopamine
nAChRs are activated by nicotine molecules and transmits dopamine. This is immediately followed by shutdown- where they cannot respond to _______.
Neurotransmitters.
When nAChRs cannot respond to neurotransmitters, they are said to be ________.
Desensitised.
What is the result of nAChRs becoming desensitised?
- Leads to a downregulation
- A reduction in the number of active neurons because fewer of them are available.
Where are nAChRs found?
Ventral Tegmental Area (in the brain)
What happens when nAChRs are stimulated by nicotine?
- Neurons transmit dopamine along the mesolimbic pathway to the nucleus accumbens (NA).
- This triggers the release of more dopamine from the NA to the frontal cortex.
- Dopamine is also transmitted along the mesocortical pathway to the frontal cortex
What are the two pathways that are a part of the brain’s dopamine reward system?
- Mesolimbic
- Mesocortical
Give 3 impacts of the brain’s dopamine reward system being activated (via nicotine):
- Mild euphoria
- Increased alertness
- Reduction of anxiety
Explain how withdrawl occurs?
- A person does not use nicotine for a prolonged period of time- no nicotine in their system/body
- nAChRs become functional again, so dopamine neurons resensitise and become more available.
- nAChRs become overstimulated by ACh (because there is no nicotine to bind to them), which increases their sensitivity.
Why do smokers often say that their first cigarette of the day is the best?
- Withdrawl starts to occur
- nAChRs become functional, sop dopamine receptors resensitise and become more available
- nAChRs become overstimulated by ACh, which increases their sensitivity
- The first cigarette of the day reactivates the dopamine reward system, alongside the increased nAChR sensitivity.
Explain dependence and tolerance in terms of nicotine addiction:
- The smoker avoids unpleasant physiological and psychological withdrawl states by having another cigarette.
- This creates a constant cycle of daytime downregulation and nighttime upregulation, creating long-term desensitisation of nAChRs.
- Continuous exposure to nAChRs causes permanent changes to brain neurochemistry- a decrease in the number of active receptors.
- A tolerance develops as a smoker has to smoke more to get the same effects.
Name the 4 evaluation points for nicotine addiction via brain neurochemistry:
- Research support (S)
- Real world application (S)
- Withdrawl symptoms (L)
- Determinism (L)
Explain research support (S) as an evaluation point for nicotine addiction via brain neurochemistry:
- Support from human research
- McEvoy studied schizophrenics who were taking a dopamine antagonist drug (reduces dopamine transmission).
- The schizophrenics showed a significant increase in smoking.
- This was because they used smoking as a form of self-medication, they used nicotine as a way to make up for the dopamine loss.
- Supports the view that dopamine has a key role in the neurochemistry of nicotine addiction.
Explain real world application (S) as an evaluation point for nicotine addiction via brain neurochemistry:
- Neurochemistry leads to new treatments e.g. nicotine replacement therapy (NRT)
- NRTs deliver a controlled dose of nicotine
- This nicotine binds to nAChRs and mimics the effects of nicotine from cigarettes, inducing dopamine release
- Allows for cravings to be satisifed in a way where dosage is cleaner and can be reduced
Explain determinism (L) as an evaluation point for nicotine addiction via brain neurochemistry:
- The neurochemical explanation does not fully explain withdrawl.
- The theory states that withdrawl symptoms mainly depend upon the amount of nicotine in the body (e.g. levels of nicotine within the blood)
- Gilbert states that these factors are not strongly correlated. He argues that withdrawl depends more on environment and personality
- E.g. people with neuroticism generally experience worse withdrawl symptoms than people who are emotionally stable
Explain determinism (L) as an evaluation point for nicotine addiction via brain neurochemistry:
- The neurochemical explanation is biologically deterministic
- Suggests that we become addicted to nicotine because of chemical events involving the dopamine reward system that is beyond our control, including withdrawl.
- So nicotine addiction is inevitable for someone who starts smoking.
- However it may not be inevitable for everyone as some people start to smoke but do not become addicted, e.g. due to their personality.
What are the two main explanations for nicotine addiction?
- Neurochemical
- Learning theory
The learning theory uses a _______ approach.
Behaviourist
For the learning theory explanation of nicotine addiction, it can be explained through _______ and _______ __________.
Classical and operant conditioning.
How does positive reinforcement maintains nicotine addiction- mention the neurochemical cause of this:
- If the consequences of a behaviour are positive e.g. feeling pleasure then the behaviour is more likely to occur again.
- This pleasure occurs because of its effects on the dopamine reward system, where dopamine release is stimulated in the nucleus accumbens, producing a feeling of mild euphoria, which the smoker finds pleasurable and positively reinforces their behaviour.
How does negative reinforcement maintain nicotine addiction - mention the neurochemical cause of this:
- Absence of nicotine leads to acute withdrawl, with significantly unpleasant symptoms like sleep disturbances, aggression and anxiety.
- These wide-ranging withdrawl symptoms make it hard for the smoker to abstain from nicotine for so long, and so they reduce/stop these effects by smoking again.
- Smoking a cigarette is negatively reinforcing nicotine addiction because it stops unpleasant stimulus
The pleasurable effect of smoking is known as the ______ reinforcer.
Primary
Why is pleasure gained from smoking a primary reinforcer?
- It is intrinsically rewarding due to its effects on the dopamine reward system- so an individual is more likely to smoke again.
- Any other stimuli that are present at the time become associated with this pleasurable effect
- Tbe other stimuli are secondary reinforcers/cues because they take on the properties of the primary reinforcer and become rewarding.
What is the primary reinforcer with a nicotine addiction?
Cigarette (nicotine source)
What are the secondary reinforcers/cues with a nicotine addiction?
Other stimuli associated with the cigarette:
- Lighters
- Environment e.g. pub
- Smell of smoke
What is cue reactivity?
Cravings and arousal that is triggered when they encounter cues related to the pleasurable effects of smoking (for nicotine addicts specifically)
Secondary reinforcer stimuli acts as cues because their presence produces a similar physiological and psychological response to _______ itself.
Nicotine
What are the 3 main elements of cue reactivity?
1) Subjective desire/craving for cigarette, which is self-reported
2) Physiological signs of reactivity, including autonomic responses like increased heart rate
3) Objective behavioural indicators such as how many ‘draws’ are taken on a cigarette and how strongly.
Name the 4 evaluation points for nicotine addiction via learning theory:
1) Research support (S)
2) Strength for cue reactivity (S)
3) Real-world application (S)
4) Animal research (S/L)
Explain research support (S) as an explanation point for nicotine addiction via learning theory:
- Animal studies support the theory
- Levin et al found that rats that were given the opportunities to lick two water spouts, one infused with nicotine, chose to lick the nicotine infused water spout significantly more- with the number of licks increasing substantially each session.
- Suggests the effects of nicotine positively reinforcing self-administration in rats, implying there is a similar mechanism in humans.
Explain strength for cue reactivity (S) as an explanation point for nicotine addiction via learning theory:
- Supported by research with humans for the effects of cues.
- Carter and Tiffany conducted a meta-analysis of 41 studies into cue reactivity.
- Addicts and non-addicts were shown images with smoking-related cues (e.g. lighters, ashtray).
- The addicts were found to act more strongly to cues- showing both physiological and psychological arousal.
- Suggests that dependent smokers (addicts) learn secondary associations between smoking-related stimuli and the pleasurable effects of smoking.
Explain real world application (S) as an explanation point for nicotine addiction via learning theory:
- There are nicotine treatment programmes based on classical conditioning principles.
- Aversion therapy uses counterconditioning to treat nicotine addiction by associating the pleasant effects of smoking with an aversive stimulus (e.g. painful shock)
- A study done by Smith et al found that when participants shocked themselves after engaging with any smoking-related behaviour , 52% of the patients were no longer smoking- compared to 20% of people that successfully stop smoking without therapy.
- Therefore treatments based on the learning theory can save NHS resources, improve health and save lives.
Explain animal research (S/L) as an explanation point for nicotine addiction via learning theory:
- It is reasonable to use non-human animals to study addiction in humans.
- The conditioning mechanisms involved in nicotine addiction are the same in humans and mammals.
- However animal-human comparisons are flawed as human mechanisms involved in nicotine addiction are more complex.
- E.g. cognitive factors influence learning processes in human addiction, meaning that humans think about reinforcers in a different way than other mammals do e.g. rats.
