Addiction- Biological explanations

Question 1

What are the 2 biological explanations for addiction?

Answer 1

1) The role of dopamine
2) Addiction genes

Question 2

What is my first choice for the biological explanations for addiction?

Answer 2

The role of dopamine

Question 3

What are the 3 aspects to the role of dopamine?

Answer 3

1- The mesolimbic pathway
2- Tolerance and withdrawal
3- Maintaining addiction

Question 4

Key points about the mesolimbic pathway

Answer 4

The reward pathway
- whenever we engage in addictive behaviours the pathway is activated
- creates a pleasurable feeling which reinforces the behaviour
- drugs also reward centres to activate
- pleasurable feedback is at the very heart of addiction

Question 5

The mesolimbic pathway
NACs and VTAs

Answer 5

The nucleus accumbens travel from the VTA to NAC where a jolt of pleasure is felt
Ventral Tegmental Area
- dopamine is released from here

Question 6

Research support for the mesolimbic pathway
Joutsa et al and Boileau

Answer 6

J- D levels were increased in Ps who were given a gambling task, regardless of whether the outcome was a win or not
B- alcohol increased D levels in the brain

Question 7

What does research from Joutsa and Boileau suggest about the mesolimbic pathway?

Answer 7

Addictive substances and behaviours trigger the release of dopamine in the mesolimbic system

Question 8

2- How is tolerance created

Answer 8

The brain adapts in response to experience and will strive to reach equilibrium, balance//stability
- if a drug is consumed regularly, it will alter the function of the brain as we upset the balance
- the brain will adapt to minimise the effect of the drug and restore normal function
- a higher and higher dose will be needed to achieve the same effect

Question 9

2- How is withdrawal created?

Answer 9

If a drug is used regularly, the brain compensates and adapts to maintain balance whilst the drug is present undergoing a process of neuroadaptation
- when the drug is no longer being taken, the brain becomes out of balance
- it can take neuroadaptation a long time to adapt to the absence of a drug
- causes the symptoms of withdrawal

Question 10

Why do people take drugs when experiencing withdrawal?

Answer 10

The unpleasant side effects
- now no longer being taken for its pleasurable effects, but rather to avoid the withdrawal symptoms

Question 11

Tolerance and nuerotransmitters

Answer 11

Tolerance works at the level of NTs with D2 receptors
- different receptors are compatible with different NTs
- D2 receptors are a specific type of NT that dopamine attaches itself to

Question 12

What did Volkow et al find in relation to tolerance and withdrawal?

Answer 12

Found that in users of cocaine, there was a reduction in both the number of d2 receptors in the brain, as well as a reduction in the release of dopamine
- brain removes D2 receptors so that less dopamine can bind to it

Question 13

3- Maintaining addiction
What are the responsibilities of the frontal cortex?

Answer 13

• impulse control
• problem solving
• motivation
• social behaviour
• judgement
• decision making
  These all help to maintain addiction

Question 14

How does the frontal cortex help to maintain addiction?

Answer 14

Human brains are complex, and a simple pleasure response is not enough to explain all of the characteristics of addiction
evidence- the fact that when the drug is no longer being taken, and the negative effects of withdrawal and tolerance have disappeared, relapse can still occur

Question 15

How does Volkow et al’s research support the argument on the maintenance of addiction?

Answer 15

Cocaine addicts show abnormalities in their frontal cortex

Question 16

How does Wang et al’s research support the argument on the maintenance of addiction?

Answer 16

Addicts show an increase in activity in their frontal cortex when exposed again to the drugs or cues associated with them