What are the two theories of explaining addiction???
- brain chemistry and dopamine
- learning theory and cue reactivity
In the brain chemistry, explanation what does the A1DRD2 gene do??
Some people inherit a faulty A1DRD2 candidate gene, which means they can not produce pleasure naturally, so smoke to raise dopamine activity and receive pleasure.
Explain the course of how nicotine causes addiction through dopamine levels??
Brain chemistry theory
- The nucleus accumbens is a primary reward centre in the brain and with increased activity dopamine rises causing users to evaluate ‘smoking’ as very pleasurable, compelling further use
- Nicotine stimulates specific acetylcholine (nicotinic acetylcholine receptors - NAcR) receptors which increases alertness, memory function and learning
- At the same time, the nucleus accumbens is encouraged to release more dopamine as nicotine also stimulates endorphins that reduce GABA activity. A decrease in GABA correlates with further rises is dopamine (as GABA usually suppresses dopamine). More and more dopamine forces smokers to engage with further use
- This action causes a rise in dopamine activity in the ventral tegmental area (VTA): a critical area in the brains reward circuitry which is highly populated with NAcR. This gives nicotine a rewarding sensation
- 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
This can then cause downregulation? What is this?
Brain chemistry theory
As nicotine triggers the firing of dopamine in the mesolimbic dopamine pathway, and this acts like a reward or a ‘kick’ to the smoker. As a reward the smoker wants this again, but tolerance develops.
With LT use, the Nicotine Regulation Model (Shachter, 1977) suggests that the smokers ‘reward system’ becomes less active/sensitive (downregulation) i.e specific acetylcholine receptors become unavailable and inactive. This can create anxiety, lethargy and sadness. To avoid this, smokers continue to smoke more to maintain a certain level of nicotine in their bodies to avoid these unpleasant side effects (negative reinforcement).
Hence, with the downregulation (tolerance) in the mesolimbic pathway, an increased amount of nicotine is needed to achieve the same initial ‘kick’ as the rewarding receptors have been ground down
This is also causes up regulation. What is this?
Brain chemistry theory
What are the positive evaluations of the brain chemistry theory??
- The biochemical explanation of nicotine addiction can be praised for having research to support the theory. Paterson et al (2002) found support for the role of nicotine and dopamine through research with an epilepsy drug (Gamma-vinyl GABA). 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.
Therefore the biochemical explanation can be seen as a valid explanation for addiction as the reduction of dopamine reduced the addiction, suggesting it is an important influence in why people get addicted to nicotine. - There are practical applications that stem from the biochemistry explanation. Nicotine Replacement Therapy is a drug treatments for addiction. It is an agonist drug which acts as a REPLACEMENT for the addictive drug and produces a similar effect to nicotine itself. Nicotine replacement therapy, such as nicotine patches treat smoking addiction but giving the brain a similar reward to smoking but in a controlled way.
By helping people manage their addiction to smoking it will reduce strain on the NHS by reducing smoking related illnesses.
What are the negative evaluations of the brain chemistry theory??
- An issue with the biochemical explanation for nicotine addiction is that it could be considered biologically reductionist. This is due to the explanation suggesting that addiction is caused by nicotine acting in a rewarding way by stimulating the VTA increasing dopamine activity. By taking a reductionist view it may mean that other explanations, such as the learning explanation are missed, limiting the explanation. However, being biologically reductionist can aid research as it is the lowest level of explanation and supports parisonmy, where science favours the simplest explanation. This suggests that the biochemical explanation can be researched in a more scientific way.
- Another issue with the biochemical explanation is it may suffer from beta bias. This is when research tends to minimise or ignore differences between men and women and assume they behave the same.
Frequently, psychological research is beta-biased in that it assumes that insights derived from the study of men will apply equally well to women. Research into nicotine addiction is often conducted on men and assume that females are affected biologically in the same but this may not be the case.
Therefore we have to view research in this area with caution when explaining both men and women in relation to nicotine addiction.
What does the learning theory assume??
Acquired habits which are learned
Things that can be unlearned
Learning can take place in one of three ways:
Observational SLT processes
Classical conditioning
Operant conditioning
What are the 3 ways of a nicotine addiction through the learning theory??
- SLT
- operant conditioning
- cue reactivity
Explain smoking imitation through slt???
Learn through observation
Initiation of behaviour
E.g. parents / friends
Vicarious reinforcement
Brynner (1969) 🡪 media creates images of smoking as being attractive and tough (SLT)
Explain smoking maintenance through operant conditioning??
Basic Understanding ?
Consequences to actions-positive and negative
Behaviour likely to be repeated if rewarded
Link this understanding to addiction…
2 forms:
Positive reinforcement – increases likelihood of behaviour
e.g. Pleasure / relax / attention of friends
Negative reinforcement – remove something bad
e.g. withdrawal symptom
Explain smoking maintenance through cue reactivity??
Basics of classical conditioning….
Learning through association
Effects of smoking (pleasure) = Primary reinforcer (not learned 🡪 dopamine)
Stimuli present at same time become associated with the pleasure = secondary reinforcer 🡪 become rewarding in their own right.
Where/when might you be most likely to see people smoking?
Pub
With friends
Night out
These situations over time become associated to be secondary reinforcers
These also act as cues 🡪 their presence produces a similar physiological and psychological response to nicotine itself (cue reactivity)
What are the positive evaluations of the learning theory???
- The learning explanation of nicotine addiction can be praised for having research to support the theory.Harakeh (2007) took data on 428 families with two adolescent children between the ages of 13 and 17 years. The data was collected through surveys and was part of a bigger health investigation. They found non-smoking adolescents with older siblings that smoked and those with a smoking best friend were more likely to have started smoking 1 year later. However, older adolescents were not affected by smoking of their younger siblings.
Therefore the learning explanation can be seen as a valid explanation for addiction as the participants were affected by watching an older sibling smoke, suggesting it is an important influence in why people get addicted to nicotine. - One key strength os the learning explanation for nicotine addiction is there are great practical applications such as cue exposure therapy. Addictive behaviours are aroused in the presence of various stimuli, or cues. For instance, smoking is often associated with drinking, so alcohol becomes a ‘cue’ that stimulates smoking. Cue exposure involves presenting the cue to the individual and helping them control their reaction to it i.e. to develop coping strategies. In this way the response of ‘smoking’ in the presence of alcohol fades away or extinguishes, This is thought to be more effective than simply trying to avoid the cues, for example never drinking.
What are the negative evaluations of the learning theory???
- There is however, research to refute the learning explanation for nicotine addiction. Robinson & Berridge (1993) argue that many people try drug taking yet do not become addicted despite the rewarding experiences on offer. This suggests other factors must also be at work, that allow some yet not others to become full blown addicts.
This reduces the validity of the learning explanation as it must be more complicated than the learning theory suggests. - An issue with the learning explanation for nicotine addiction is that it could be considered environmentally reductionist. This is due to the explanation suggesting that nicotine addiction is caused by being reinforced by smoking such as feeling calm. By taking a reductionist view it may mean that other explanations, such as biochemical explanation are missed, limiting the explanation. However, being environmentally reductionist can aid research as it is the middle level of explanation and supports studying behaviour in a scientific way.
