drugs week 3

Question 1

explain simply how learning theory can explain addiction

Answer 1

• dominant approach
• drug and non-drug addictions
• behaviour in relation to reinforcement and punishment
• certain background factors may make sensation to reinforcement from substances more likely.

Question 2

explain the role of positive reinforcement in addiction (not biological)

Answer 2

• ‘liking’ stage
• reinforcement not always the case- smoking
• other reinforcement = social acceptance/bonding.
• contiguity : behaviour and effect linked in time
• ROA : how soon you feel the effect.

Question 3

how does ROA and positive reinforcement explain addiction

Answer 3

drugs that after faster routes of administration are more likely to be positive reinforced as the link between the behaviour and the effect is made - contiguity

Question 4

explain how addiction can be classically conditioned

Answer 4

cues in environment become associated with drug use
initial exposure: NS (environment)- US (drug) -UR (reaction to drug)
Subsequent: CS (environment) - CR (Response to drug).
Brain expect drug use, downregulates dopamine receptors, drug no taken = deficit = withdrawal state.

Question 5

explain positive reinforcement and addiction in terms of neural system

Answer 5

• drug release dopamine in mesolimbic and mesocortical DA systems ascending from VTA
• nuclease accumbens
  -induces human to seek drug
• cues associated with drug = drug seeking

Question 6

whats the role of nucleus accumbens in addiction

Answer 6

• many DA receptors in regards to reward system
• if certain drugs trigger this reward system more likely to have it.

Question 7

what type of drug is more easily conditioned to become addictive and why?

Answer 7

psychostimulants - directly release dopamine and work on the nucleus accumbens which is involved in the reward system.

Question 8

how does negative reinforcement play a role in addiction

Answer 8

• removes unpleasant stimuli
• reduce pain, psychological discomfort
• removal of withdrawal, goes from liking to wanting (psychological or physiological)
• contiguity: time between effect and behaviour
• caffeine and nicotine more negatively reinforced.

Question 9

explain pathway of addiction in terms of reinforcement

Answer 9

initial liking = positive reinforcement
withdrawal goes to more wanting = negative reinforcements

Question 10

what are some treatments that use reinforcement and classical conditioning to treat addiction

Answer 10

reinforcement: contingency management therapy
Cue exposure therapy: based on principle of extinction.

Question 11

what are some research that demonstrates the role of classical conditioning and cues on drug use

Answer 11

Robins (1975) : U.S. soldiers become depend on heroin in Vietnam rarely continued use when at home
Wickler (1948) : conditioned opoid withdrawal in group therapy drug-free Pps when they talked about the drug = sniffing, yawning..

Question 12

Conditioned place preference

Answer 12

• place = NS
• repeated use of drug = Environment = CS
• Spend more time in that environment even without drug
• CS elicit drug responses

Question 13

what study demonstrates Conditioned place preference

Answer 13

Siegal et al (1982) : when in environment that drug was originally taken to rats brain downregulates so rat is prepared for drug and does no overdose.
Ehrman et al (1992); opioid detoxed pps were given signalled or unsignalled doses of hydromorphone or placebo.
Levine (1974) : heroin users inject water instead provides mild high.

Question 14

How does genetics play a role in addiction?

Answer 14

twin studies: MZ and DZ twins, 50% variation in risk of becoming addicted.
expressed in protein structures which may alter drug action - amount of enzyme responsible for metabolism of certain drugs may be missing or reduced.

Question 15

what the issues of claiming that addiction runs in the family

Answer 15

• could be genetic but could also be psychosocial (trauma)
• why we need to look at precise genes.
• but could still be a genetic predisposition - individual could have both genetic vulnerability and bad environment.

Question 16

gateway hypothesis

Answer 16

• use of psychoactive drug presents increasing probability of further drug use.
• nicotine, alcohol, cannabis.

Question 17

mesolimbic vs mesocortical reward system

Answer 17

mesolimbic = start is ventral tegmental area and increase dopamine in nucleus accumbus, amygdala and hippocampus. Pleasure/rewards, seeking behaviours, addcition.
mesocortical = starts in ventral tegmental area and travels to cerebral cortex (mainly frontal lobe). Cognition, memory, attention, learning.
Dopamine more thougt now to be involved in memory and learning instead of just euphoria.

Question 18

what was the original dopamine hypothesis

Answer 18

• addictive drugs release dopamine but non- addictive psychoactive drugs do not.
• DA release in mesolimibc and mesocortical pathways is highly rewarding this become addictive.

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Question 19

reward prediction error.

Answer 19

• difference between received and predicted reward.
• if we keep receiving the expected reward (dopamine) habituation will occur.
• conditioned cues make us expect a reward, higher dopamine then expected as we have gotten use to it.

Question 20

what study demonstrates Reward prediction error

Answer 20

Konova et al (2023) : cocaine dependent users vs non, expected dopamine reward same for both, but signal weaker for cocaine dependent users.

Question 21

what evidence shows the role of DA in rewards

Answer 21

Olds and Milner (1954) : rats willingly self stimulate certain brain areas with electric impulses, perceived to be primary positive reinforcement. these brain areas were shown to be heavily made of DA neurons.

Question 22

what are the issues with the dopamine hypothesis

Answer 22

medication that alter DA function should be able to treat addiction
block dopamine = block reward from drugs that stimulate dopamine.
evidence against: blocking DA receptors in rats fails to reduce rewarding action of opiates
Leyton et al (2005) : depletion of DA before cocaine use in experimental users had no effect on euphoria experience by drug.

Question 23

due to research against the dopamine hypothesis what does current research suggest?

Answer 23

stimulants act on DA receptors
Dopamine must be the mediator.
correlation not a causation
other drugs can indirectly affect DA, don’t show same relationship.
dopamine has a role in misuse and may be involved in the motivation, other roles in addiction still unclear.

Question 24

Incentive sensitization theory, what is it?

Answer 24

Robinson and berridge, 1993: Drug wanting vs drug liking
wanting outlives withdrawal, negative reinforcement. cannot account for cravings.
drugs wanted more and more liking mat decrease.
dopamine system attribute incentive salience to stimuli associated with activation of the stimuli. Repeated use of drugs hypersensitises this system.

Question 25

what is the support for incentive sensitisation theory.

Answer 25

Lambert et al (2006) : reported a discrepancy between liking and wanting cocaine in long-term dependent users.
Ostafin et al (2010) : wanting vs liking in relation to alcohol= wanting predicted drinking better than liking, longer the drinking behaviour lower the liking.