Lec 8 - Final

Question 1

Substance Addiction

• 3 reasons to take drugs for addicts
• 5 major symptoms (DR SCC)

Answer 1

Substance Addiction

• CDC = American’s Health Canada
• Drug Addiction
  
  • Compulsive substance use leading to significant impairment & distress
    
    • Not the same as physical dependence
  • Drugs taken to (a) feel good, (B) relieve stress, (c) Enhance performance, & (d) curiosity
• Symptoms
  
  • Cravings: strong urge to use drug
  • Lack of control: desire to control/cut down drug use
    
    • You take drugs; if you enjoy it and have no desire to cut it down, you are not considered addicted
  • Social problems: failure to complete major goals at home/work; leisure activities abandoned
    
    • Ex. you love Frisbee, since you are high, you don’t feel like playing Frisbee
  • Risky use: continued use despite known problems; drugs used in risky settings
  • Drug effects: Tolerance & withdrawal symptoms

Question 2

DA, wanting vs craving

• Standard view of DA
• Berridge & Robinson
  
  • lesioned rat brains results and sugar water
  • electrode on rats results and sugar water
  • Conclusion
• Updated view on DA
  
  • Lesioned vs electrode rats on work
  • Conlusion
  • Incentive salience
  • wanting vs motivated
• What this means about addicts

Answer 2

An aside on dopamine

• What is dopamine (DA)?
  
  • Organic chemical that plays important role in brain & body
  • In Brain, it acts as a neurotransmitter that is important for motivation & reward
  • Many addictive drugs increase DA
• What is a neurotransmitter?
  
  • A chemical released by neurons to send signals to other neurons

What is dopamine for? NOT for Liking

• Standard view: DA mediates the pleasure of reward (from good food, drugs, sex, music, etc)
• Berridge & Robinson
  
  • But: Lesioned rats with no brain DA, still liked sugar water
  • Put electrode in rats to increase DA; the rats liked sugar water the same
  • In humans, DA suppression does not reduce pleasure of cocaine

Dopamine is for “Wanting” - incentive salience

• Updated view: DA relates to “wanting” or craving; not liking
  
  • Lesioned rats with no brain DA are unmotivated; no longer worked for food
    
    • Worked for food: run on the wheel so that they can be rewarded by food
  • Electrode rats with lots of DA, 4X more willing to work for food
  • In humans, DA suppression reduces desire to consume more cocaine
• “wanting” not the same as desire to reach goal
  
  • Incentive salience: disconnected from goals, linked to reward cues, with cues becoming attention-grabbing
  • Ex. Sees a pic of friend who takes cocaine with him -> makes him want cocaine
• Addicts have a goal to quit drugs, yet “want” drugs

Question 3

DA as mechanism for reward-learning - How liking leads to wanting

• 3 stages of habituating to drugs
  
  • Base, cue reward

Answer 3

DA as mechanism for reward-learning - How liking leads to wanting

• 3 stages of habituating to drugs
  
  • A = first time taking drug
    
    • Baseline = neutral
    • Cue = sees drugs, but no expectations
    • Reward = I like that (DA spike)
  • B = expected drug is rewarding
    
    • Baseline = neutral
    • Cue = Since you expect the drug to be rewarding, DA is released (comes earlier) -> wanting
  • C = still expected drug is rewarding; but suddenly the wind blows, less cocaine present (prediction error)
    
    • Baseline = neutral
    • Cue = you expect the drug is rewarding, DA is released
    • Reward = since there is less cocaine,you expectation is not met -> DA levels drop
• DA increases first to reward
  
  • then to cue, with reward conditioning (aka classical conditioning)
• With no-reward, DA drops (negative prediction error)
• DA is especially high when cue-reward relationship is unpredictable
  
  • Ex. gambling

Question 4

• Incentive sensitization theory
  
  • initial
  • repeat use
  • Overtime

Answer 4

Addiction: “wanting” vs liking

• Incentive sensitization theory
• 
  
  • Initial try of drug: High liking, lots of pleasure; not much “wanting”
  • Repeated use: Habituate to pleasure, liking decreases so dosage increases to increase liking
  • Over time: Little liking felt, “wanting” dominates behaviour
    
    • DA becomes sensitized: “wanting” system is hyper-reactive to drug cues & settings
    • Sensitization might be permanent
      
      • Ex. IOW DA sensitization to the cues may be permanent
      • You are an alcoholic, you go to the same bar
      • When you pass the street of that same bar, seeing the street is a cue -> strong urge to drink
      • Another situation
      • You have drinking buddies; just seeing those ppl -> you have strong urge to drink
      • So, some recovering addicts have to cut off ppl from their lives as those ppl are cues to those cravings, and it may be permanent
      • Or cut off going to certain parts of the city

Question 5

pleasurable things can be addictive

• Apply 3 stages of habituating to social media use
  
  • Base
  • Cue
  • Reward

Answer 5

pleasurable things can be addictive
including social media

• Social media is liked
  
  • Social needs
  • Needs to be monitored & monitor others
• Liking begets wanting
• Might help us understand other “addictions”
  
  • Food
  • Gambling
  • Gaming
  • Marijuana
• A: Unexpected Reward
  
  • Baseline = neutral
  • Cue = neutral
  • Reward = got a buzz, like on FB -> DA spike
• B: Expected Reward
  
  • Baseline = neutral
  • Cue = buzz -> expect smth nice/ a reward -> DA spike
  • Reward = msg from romantic partner
• C: -ve prediction error type 1
  
  • Baseline = neutral
  • Cue = buzz -> expect smth nice/ a reward -> DA spike
  • No Reward = calendar reminder/spam email -> DA drop
• D: -ve prediction error type 2
  
  • Baseline = neutral
  • anticipate = expect a buzz/thought you felt smth -> DA spike
  • No Reward = no notifications from phone

Question 6

• Delay discounting
• Addicts on DD
• DD if rewarded w/ drug (control vs addicts)
• DD if rewarded w/ money (control vs addicts)

Answer 6

Addiction: View from economics
Now vs later

• Remember Delay discounting?
  
  • Value of delayed rewards (Later) is reduced compared to value of immediate reward (now)
  • Addicts: (addiction is a form of delay discounting)
    
    • Wanting now (drugs) vs. pleasure later (sobriety)

Delay discounting & addiction

• Do addicts discount future value more than non-addicts?
  
  • Yes!
• Who discounts more? (graph)
  
  • Opioid-dependent vs. non-dependent
    
    • Discounting rates depend on type of reward;
    • more discounting for drug itself (see bottom graph)
  • Also seen w/
    
    • Heavy vs. light drinkers
    • Problem (alcoholics) vs light drinkers
    • Problem vs. non-problem gamblers
    • Smokers vs non-smokers
• • Y-axis: value of smth currently
• X-axis: delay in months
• Top graph
  
  • Control group money situation discount: want $40 today instead of $100 in 1 yr
  • Heroin addicts & money: want $10 today instead of $100 in 1 year
• Bottom graph
  
  • Heroin addicts & money: want $10 today instead of $100 in 1 year
  • Heroin addicts & drug: want .1g cocaine instead of 10g in a year

Question 7

Rat Park

• Drug addiction: rats in park vs cage
• Which trait increases likelihood of addicion?

Answer 7

Who becomes addicted I?
Those who live meaningless lives

• Rats that lived “meaningful lives” rarely took or abused drugs
  
  • Bored, scared, lonely, sad rats, in contrast, drug themselves to death
  • Humans, too, will shock themselves when bored
• Addiction less product of drug, more product of person
  
  • If not drugs, meaninglessness could lead to other addictions

Who becomes addicted II?
Sensation seekers

• Sensation seeking (Zuckerman)
  
  • Trait associated for search of experiences and feelings that are varied, novel, complex, and intense
  • Risk might be ignored, tolerated, or considered to add to experience
• Sensation seekers more likely:
  
  • Extreme sports (e.g., bungee)
  • Gamble
  • Consume and abuse drugs

Question 8

AA and legalize drugs

• AA effectiveness and motivation
• Portugal

Answer 8

Treating addiction
Alcoholics Anonymous

Does AA work?

• Not really (among randomized experiments)
  
  • Effects on abstinence
  • Looked at those in AA vs not in AA
• AA meetings, randomized experiments
  
  • Those who are randomly assigned to AA meeting drank more (-ve correlation)
  • AA vs no treatment or alternative treatment
• AA meetings, non-randomized experiments
  
  • Significant: those who attend AA -> less OH
  • AA vs not attend AA
  • AA more vs attended less
  • AA vs meds
• AA residential programs (stay for a wk), randomized -> sig
• ‘’ non-randomized -> non-sig
• Note: Randomized trials are not ideal for drug treatment b/c
  
  • Addicts are FORCED to go to rehab when might not want to quit
  • Ex. court mandate
• Yes! (in correlational studies)
  
  • Relationship between AA attendance & abstinence
  • Dose-response relationship; more AA, higher rates of abstinence
  • More AA at time 1 (more attendance in AA at time 1) relates to more abstinence at time 2
  • But: this relationship might not be specific! People who go to AA might be more motivated than people not going to AA
  • Correlation ≠ causation

A better solution?
Legalize all drugs!

• Portugal: decriminalized drugs
• Used to have most opioid use in EU
• Decriminalized drugs
• Now, lowest opiod use in EU
• IOW: fewer overdoses, fewer actual users, lower rates of HIV from needles
• Coupled with messaged about harm reduction not prevention