7: Neurobiology of addiction behaviours

Question 1

What is dependence?

Answer 1

Strong desire to take a substance, with difficulty stopping, and persistent use despite evidence of harm

Developing a tolerance to a substance

Neglect of alternative hobbies

Going into a withdrawal state when going cold turkey

Question 2

Does addiction/dependence only apply to substances?

Answer 2

No

gambling, adrenaline junkies, games, social media

Question 3

What is incentive salience?

Answer 3

Process which attributes ‘want’ to a stimulus

i.e activates your reward pathway for doing something

Question 4

Which three parts of the brain are involved in incentive salience and the reward pathway?

Answer 4

VTA (ventral tegmental area)

Nucleus accumbens

Pre-frontal cortex

Question 5

Which neurotransmitter is released from the ventral tegmental area and the nucleus accumbens in incentive salience?

Answer 5

Dopamine

Question 6

What is the function of incentive salience?

Answer 6

‘Reward’ for behaviours which keep you alive / pass down your genes

so food, shelter, sex

Question 7

___ drugs affect the reward pathway.

Answer 7

Addictive

Question 8

Addictive drugs e.g nicotine, alcohol and opiates cause the release of which neurotransmitter in the brain?

Answer 8

Dopamine

Question 9

Which process do addictive drugs hijack by releasing dopamine in the brain?

Answer 9

Incentive salience

Question 10

Why do people who are addicted to certain drugs or behaviours begin to neglect other interests?

Answer 10

Incentive salience

other activities can’t compete with dopamine release

Question 11

Dopamine receptors are downregulated in response to repeated exposure to an addictive drug.

What process is this an example of?

Answer 11

Tolerance

Question 12

What is the only way to experience reward when you have tolerance to an addictive drug?

Answer 12

Take a higher dose of the drug

Question 13

How long does tolerance take to wear off when you’re abstinent from a drug?

What does this mean in the interim?

What does this predispose the patient to?

Answer 13

Significant period of time

Reward threshold is still raised, normal life seems boring by comparison

Relapse

Question 14

The feeling of reward experienced by initially taking a drug is an example of ___ reinforcement.

Answer 14

positive reinforcement

Question 15

Feeling crap unless you take a drug is an example of ___ reinforcement.

Answer 15

negative reinforcement

Question 16

Which part of the frontal lobe is responsible for executive function?

Answer 16

Pre-frontal cortex

Question 17

Which part of the brain regulates your decision making, memory and behaviour?

Answer 17

Frontal lobe

pre-frontal cortex

Question 18

When does the pre-frontal cortex finish developing?

Answer 18

20s

So emotions > executive function when you’re younger

Question 19

The younger you experiment with drugs, the (more / less) likely you are to be addicted to them.

Answer 19

more likely

Question 20

What is the proper name for the reward pathway?

Answer 20

Mesolimbic pathway

Question 21

The brain makes associations between visual and audio ___ and addictive drugs.

Answer 21

cues

Question 22

Which parts of the brain are responsible for memory and learning?

Answer 22

Hippocampus

Amygdala

Question 23

Which parts of the brain are responsible for reward?

Answer 23

Ventral tegmental area

Nucleus accumbens

Question 24

Which part of the brain regulates the signals coming from the reward pathway?

Answer 24

Pre-frontal cortex

Question 25

Which part of the brain is involved in motivation?

Answer 25

Orbito-frontal cortex

Question 26

Which neurotransmitter is released in response to stress?

Answer 26

Dopamine

Question 27

How does

a) acute
b) chronic

stress affect drug addiction?

Answer 27

a) Acute stress - dopamine release; cue to use drug
b) Chronic stress - chronic dopamine release; upregulation of dopamine receptors; threshold for reward increased; more likely to reach that by using drugs
i. e all bad