ADDICTION: Bio - Dopamine A01

Question 1

Dopamine A01 Names

Answer 1

Olds & Miller
Joutsa et al.
Boileau et al.
Volkow et al.
Volkow
Robinson & Berridge
Volkow
Bolla et al.
Wang et al.

Question 2

Olds & Miller

Answer 2

Addiction - Dopamine
Placed electrodes onto a particular region of a rat’s brain and stimulated it every time the rat went into a corner

• Rats kept returning to the corner so the conclusion was made that the rats experienced pleasure from the brain stimulation
• Brain area was labelled the ‘pleasure centre’ / ‘reward centre’
• Brain pleasure often prioritised over other behaviours (e.g. eating)

Question 3

What is dopamine?

Answer 3

Mesolimbic Pathway:

Ventral Tegmental Area
- Where dopamine is released after pleasurable experiences

Nucleus Accumbens (NAc)
- Where the sense of pleasure is perceived

The reward pathway has evolved in humans as an adaptive response to behaviours that are good for us (eating / sex - survival)
- Become maladaptive in the case of addiction

Research shows addictive substances and behaviours trigger the release of dopamine within the reward pathway in humans and animals

Question 4

Joutsa et al.

Answer 4

Addiction - Dopamine A01
Dopamine levels were increased in ppts given a gambling task whether it resulting in a win or a lose

Question 5

Boileau et al.

Answer 5

Addiction - Dopamine A01
Alcohol increases dopamine levels in the brain

Question 6

Dopamine: Tolerance & Withdrawal

Answer 6

Tolerance to the effects of drugs or addictive behaviours is experienced as dopamine receptors become less sensitive to the effects
Volkow et al

Question 7

Dopamine: Tolerance & Withdrawal - Volkow et al.

Answer 7

Decrease in D2 receptors & Dopamine release

• Addict will need to engage more in the substance / behaviour to experience the same sensation
• If the addict stops, they will experience unpleasant withdrawal symptoms
• The aim of engaging in addictive behaviour / substance is to avoid withdrawal symptoms rather than experiencing the initial pleasure

Question 8

Dopamine: Maintaining Addiction - The role of the frontal cortex

Answer 8

Volkow - Addiction is caused by changes in the frontal cortex caused by dopamine
- Frontal Cortex - Linked to higher cognitive functions (decision making/ memory)
- Addictions can change the brain circuits that decide what to pay attention to
- Brain attaches too much importance to the behaviour & associated cues

Question 9

Dopamine: Maintaining Addiction - Robinson & Berridge

Answer 9

Dopamine makes a person want to engage > making them like it

• Explains many addicts reporting that they no longer enjoy the experience but must satisfy the addiction cravings

Question 10

Dopamine: Maintaining Addiction - E.g. Cocaine Addicts

Answer 10

Volkow - Cocaine addicts have abnormalities in their frontal cortex

Bolla et al. - Cocaine addicts show impaired performance in tasks requiring the use of brain processes linked to the frontal cortex (decision making)

Wang et al. - Addicts show an increase in activity in their frontal cortex when exposed to drugs or associated cues