DRUG ABUSE AND ADDICTION

Question 1

three factors required for addiction

Answer 1

1. habitual drug use that persists in spite of the adverse effects on social life and health. relapse often.
2. drug seeking behaviour (thinking about drug and acquiring drug)
3. physical dependence - suffer from withdrawal symptoms that motivate them to return to using

Question 2

define withdrawal

Answer 2

bodies reaction to elimination of drug from system after repeated drug exposure

Question 3

two factors that influence development of addiction

Answer 3

1. route of administration (IV more potent) fast onset shorter duration likely to produce addiction
2. genetic variation (polymorphisms that increase/decrease activity of proteins) influence responses to drugs

Question 4

Common alcohol polymorphism

Answer 4

alcoholics tend too have higher tolerance because they metabolize EtOH quicker

Question 5

Two theories of drug addiction

Answer 5

1. Physical Dependence Model - desire to curtail withdrawal symptoms
2. Postive reward model - driven by pleasurable feelings

Question 6

problem with physical dependence model

Answer 6

1. relapse often occurs after withdrawal symptoms have passed.
   2, additionally some dont have severe withdrawal symptoms.
2. detoxified users still remain addicted
3. treatments used to curb withdrawal are not 100% effective

Question 7

problems with positive reward model

Answer 7

1. habitual use continues even if rush is gone and not as good as past
2. drugs like nicotine dont give as much of a euphoric rush but are still addictive

Question 8

reward circuit

Answer 8

interconnected brain regions responsible for acute rewarding/reinforcing effects of abused drugs

Question 9

Natural rewards also increase DA levels like drugs of abuse. what is the difference

Answer 9

magnitude of DA release by drugs of abuse is 10x greater than natural

Question 10

What do drugs of abuse do

Answer 10

trick brain into thinking this is important and causes brain o start forming associations with cues associated with drug taking.

Question 11

drug reward

Answer 11

positive drug associated experiences like subjective high, euphoria, pleasurable sensations

Question 12

two components of reward

Answer 12

liking (pleasurable, hedonic effects)

wanting = craving, willingness to work for the reward

Question 13

what is dopamine not

Answer 13

not involved in making you like the good things but helps you get the good things (wanting)

Question 14

so what is the function of DA in reward?

Answer 14

DA neurons turn on when something important happens like an unexpected reward (e.g. drug use) and facilitates learning about reward related cues and may increase the likelihood of doing those actions/approaching stimuli that led to rewards again

Question 15

Self administration assay (FR)

Answer 15

lever pressing to administer drug in rats on a fixed ratio

Question 16

What do the dose response curve show in FR schedules

Answer 16

Inverted U shape, golden zone to take drugs.

higher doses p satisfaction and/or aversive reactions lead to decreased lever pressing

Question 17

Describe the PR drug reinforcement assay

Answer 17

# of presses to get each dose increases after delivery per dose 
measures the breakpoint (number of presses where rats give up because its too much work)
- measures motivation of rats to obtain drug

Question 18

Why do we think DA is involved in drug reinforcement. what happens if you deplete DA

Answer 18

in NAc if you deplete DA, it abolishes learning to self-administer drugs can conclude that DA is critical for MOTIVATING self administration

Question 19

describe conditioned place preference test

Answer 19

one side - given nothing
one side - given drug
area where rat spends more time is reflective of whether the drug is rewarding

Question 20

what does blocking DA receptors do for place preference

Answer 20

abolishes place preference for ALL Drugs of abuse

Question 21

pairing drugs of abuse with cues causes what and is mediated by what

Answer 21

learning and induce approach behaviour, linked to DA transmissions in the NAc and interactions with amygdala

Question 22

Describe preference test

Answer 22

look at slide 13 if need help

Question 23

What does repeated exposure to all addictive drugs do

Answer 23

sensitize DA transmission, increased motivation to seek drugs in response to cues

Question 24

describes three steps of the model of drug relapse and DA

Answer 24

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Question 25

Which areas are more responsive to triggers (3) in the DA system

Answer 25

prefrontal cortex
amygdala
NAc
related to increased drug craving

Question 26

4 roles of DA in addiction

Answer 26

1. addictive drugs increase mesolimbic DA levels
2. tricks brain into thinking something important is going on and to make associations
3. these cues increase DA
4. prolonged drug use hypersensitizes the DA system

Question 27

Incentive-sensitization hypothesis

Answer 27

cues associated with drug taking take control over behaviour. DA system and learning about drug related cues become sensitized even after tolerance to hedonic effects develops.

Question 28

3 neuroadaptation with repeated drug use

Answer 28

1. DA sensitization
2. Down regulation of reward circuitry
3. gradual recruitement of the anti-reward system

Question 29

drug taking theory by knob

Answer 29

Initially people take drugs because they make you feel nice. And intake might increase in the beginning.
Then they go through abstinence which causes no negative effects but then they start craving and this is when you make the transition. It moves from impulsive taking to compulsive taking and then you want to get rid of the withdrawal feelings that are bad.
They just want to feel better mentally (dysphoric mood) so in other words the emotional withdrawal persists and this is why people take drugs.

Question 30

In drug addicts, the grey matter volume of the PFC is

Answer 30

reduced, function is impaired

Question 31

chronic drug users have fewer ______ in striatum

Answer 31

D2 receptors

low d2 is associated with low PFC neural activity and serve to put a brake on certain actions.