Drug Addiction and Relapse

Question 1

What is the Incentive Salience Theory?

Answer 1

• addiction is due to excessive wanting
• dopamine is the central neurotransmitter of addiction
• wanting is mediated by DA
• drug addicts come to want cues associated with drugs (not the drugs themselves)
• example = a lighter can elicit DA release in smoking addicts

Question 2

What is the physical dependence theory?

Answer 2

• addiction due to increased stress relief
• drug users whose intake has reached a level sufficient to induce physical dependence are driven by their withdrawal symptoms
• MP increases DA binding
• withdrawal increases stress (negative reinforcement)
• drives people to take more drugs to compensate

Question 3

What is the positive incentive theory?

Answer 3

• addiction is due to people seeking drugs out for their positive effects
• this could be due to drugs being highly rewarding, or goal directed seeking driving addiction which creates habits
• people are willing to endure danger to get rewards
• implicates DA release in dorsal striatum
• handles goal directed actions vs. habit balance

Question 4

What is conditioned place preference in rats

Answer 4

in a light-dark box chamber, rats naturally prefer the dark side
by pairing the light side with a drug, they prefer the light side
- this conditioned their preference

Question 5

what is drug self administration in rats

Answer 5

rats will press a lever to get drugs delivered intravenously (IV)
immediately becomes available in the blood
alternatively, they press a lever for drugs microinjected into the brain directly

Question 6

What evidence is there for NAC (nucleus accumbens) role in addiction?

Answer 6

the VTA –> NAC implicated in addiction (reward)
- lab animals will self-administer drugs into NAC (this elevates dopamine levels)
- lesions to NAC/VTA block self-administration of drugs

Question 7

What are the three types of relapse?

Answer 7

Cue-induced relapse, context-induced relapse, and stress-induced relapse

Question 8

What is cue-induced relapse?

Answer 8

cues (CSs) associated with drug taking will elicit strong DA release and craving
the cues are specific to the action

Question 9

What is context-induced relapse?

Answer 9

drug taking can easily relapse if it occurred at the person’s home
returning home will increase craving, tempting someone to relapse

Question 10

What is stress-induced relapse?

Answer 10

stress can exacerbate symptoms of withdrawal
stress increases CRF and dopamine
Makes it more tempting to relapse