Addiction - Biological - Dopamine

Question 1

What are the four stages of addiction?

Answer 1

Initiation, Tolerance, Maintenance and Relapse

Question 2

How does dopamine link to Initiation

Answer 2

Addictive behaviours activate the mesolimbic pathway in the brain (known as the reward pathway)
The addictive behaviour triggers the release of dopamine in the ventral tegmental area of the brain leading to a sense of pleasure in the nucleus accumbens.

Humans have evolved to feel pleasure when we engage in adaptive behaviour like eating and drinking as we need it to live! However, some non-adaptive behaviours also release huge amounts of dopamine making an individual want to repeat the behaviour which leads to a maladaptive reward pathway system.

Question 3

How does dopamine link to Tolerance

Answer 3

Tolerance refers to how repeated exposure to something results in reduced sensitivity to the dopamine release as the dopamine receptors become gradually less sensitive to the effects of the substance / behaviour – this means more of the behaviour is needed to feel the same pleasurable effects in the mesolimbic system.

Volkow (1997) found those with a cocaine addiction had a decrease in D2 receptors and dopamine release than those without a cocaine addiction

Question 4

How does dopamine link to Maintenance

Answer 4

Volkow suggests that although the dopamine reward pathway is what causes an addiction to begin. An addiction is maintained because of changes in the frontal cortex.
Meaning the addictive behaviours changes the brain circuits that decide what the individual should pay attention to causing the addictive behaviour to become the focus of the individual’s life.

This explains why many addictions don’t even enjoy the addiction but engage anyway, as they get dopamine from craving the addictive behaviour rather than engaging with it

Question 5

How does dopamine link to Relapse

Answer 5

This change in brain circuits can also be used to explain why addicts relapse,

The brain-circuit changes lead to lasting memories of the addiction – so when the individual gives up they may still be exposed to environmental reminders such as being in a pub / club which will release dopamine at the thought of drinking for instance. This bit of dopamine causes the addict to crave more dopamine causing them to return to addiction.

Question 6

Name one strengths of the dopamine explanation of Addiction

Answer 6

Strength 1:
supporting research: Boileau et al (2003) 6 participants underwent a PET scan before and after an oral dose of alcohol where he found that alcohol led to dopamine increases in the brain.

Counterargument: The study lacks population validity as the study only uses 6 participants making it ungeneralizable to an overall population.

Question 7

Name one strengths of the dopamine explanation of Addiction

Answer 7

Strength 2:
application to method of modification – If addiction is truly caused by the role of dopamine that is produced when addictions engage in their addiction, we can infer that reducing this dopamine release can be used to prevent addiction. Varenicline is a drug used in individuals with a smoking / nicotine addiction. It works by binding onto the nicotine receptors which serves two functions.

1) Tricks the brain into thinking it has had nicotine leading to small dopamine release, this reduces craving symptoms.
2) Reduces the effect of nicotine if consumed as the nicotine receptors are being blocked.

Question 8

Name one weakness of the dopamine explanation of Addiction

Answer 8

Weakness 1
Opposing evidence in Yoder et al who compared dopamine activity in 24 social drinkers and 21 alcoholics, participants were given an oral alcohol infusion and then were PET scanned, results found an increase in dopamine activity in alcoholics but not social drinkers suggesting that alcohol itself is not directly linked to dopamine increase but rather addicts have different reward pathways than non-addicts.

Question 9

Name one weakness of the dopamine explanation of Addiction

Answer 9

Weakness 2
Reductionist – it is reductionist to blame addiction solely on the role of dopamine when dopamine is very complex and plays a role in many other behaviours such as schizophrenia and helping us to avoid aversive stimuli (unpleasant situations). Dopamine has been referred to as the ‘Kim Kardashian of neurotransmitters’: It has become fashionable to blame dopamine for causing a range of problems.
Brain systems are extremely complicated so although it appears that dopamine plays some role in addiction, it is not the only explanation.