Addiction

Question 1

Which circuit is known as the reward circuit?

Answer 1

Mesolimbic-dopamine circuit = final common pathway of reward

Question 2

Name the three methods for receiving chemical reward?

Answer 2

1) natural highs e.g. sex, marathon
2) Behaviour-induced highs e.g. gambling
3) Substance-induced highs e.g. cocaine

Question 3

Name the brain’s three natural highs and the illegal drug they are similar to.

Answer 3

1) endorphins (heroin)
2) anandamide (cannabis)
3) dopamine (cocaine)

Question 4

Where is dopamine released?

Answer 4

Nucleus accumbens (NAc)

Question 5

Psychotropic drugs can…

Answer 5

causeM-DA pathway to release dopamine more explosively + pleasurably than naturally

Question 6

Psychotropic drugs

Answer 6

Any drug capable of affecting the mind, emotions, and behaviour

Question 7

Name the stages that occur when you first try a psychotropic drug.

Answer 7

1) DA released
2) pleasure experience
3) amygdala learns that this is a rewarding experience = conditioned

Question 8

Name the stages that occur when after repeated tries of a psychotropic drug.

Answer 8

1) drug cues that predict pleasure cause pleasure (DA release) –> reward circuit has learnt to anticipate reward –> anticipation becomes pleasurable
2) anticipation send signals to VTA to expect reward/relief from withdrawal
3) DA release triggered
4) impulse to take drug transformed into action of finding drug

Question 9

Describe the mechanism for impulse resistance.

Answer 9

1) drug anticipation occurs
2) signals an impulsive choice to VTA
3) produces output to engage behaviour
4) Orbitofrontal cortex signals signals drug-induced cravings + support ‘vote’ for drugs
5) dorsolateral prefrontal cortex interprets signals + decides whether to take action
6) reflective reward is activated and can prevent impulse decisions
7) outcome can go either way

Question 10

VTA

Answer 10

ventral tegmental area

Question 11

Genetics

Answer 11

risk of becoming a substance abuser depends on no. of receptors

Question 12

Few receptors

Answer 12

~ taking substance doesn’t have much effect at first
~ drug becomes more rewarding as dose increases
~ own internal reward system not working as well = predisposed to keep doing drugs

Question 13

Many receptors

Answer 13

substance will be aversive/unpleasant so will not want to try again

Question 14

Low initial response

Answer 14

more likely to abuse substance

Question 15

High initial response

Answer 15

less likely to abuse substance