Discussion-Addiction

Question 1

What is drug use

Answer 1

Drug taking in any form
Does not imply problematic behavior
Drug use is not the same as drug abuse

Question 2

What is a drug

Answer 2

A substance that is used primarily to bring about a change in some existing process or state, be it psychological, physiological or biochemical
Food effects studied by nutritionists
Drug effects are studied by pharmacologists

Question 3

How are drugs classified

Answer 3

They are usually by behavioral or pharmacological effect
Stimulants
Depressants
Analgesics
Hallucinogens
Psychotherapeutics

Question 4

What are the top 5 drugs being abused

Answer 4

Marijuana 
Prescription pain relievers
Prescription tranquilizers
Cocaine
Prescription stimulants

Question 5

How is drug abuse and addiction defined

Answer 5

Clinically
-DSM-IV:
-Substance Abuse
-Substance Dependence
-DSM-V:
-Substance abuse disorders
Pharmacologically
-Compensatory mechanisms/adaptations

Question 6

Changes in the DSM-V

Answer 6

Combined substance dependence and abuse:
-Substance Use Disorders
Defined by level of severity:
-Mild (2-3 Criteria Met)
-Moderate (4-5 Criteria Met)
-Severe (6+ Criteria Met)
Distinct Terms for Specific Substances:
-Ex: Cannabis Use Disorder
-Excludes Caffeine
Drug Craving added to criteria
Behavioral Addictions:
-Gambling Disorder
-Number of criteria that must be met is different
Exclusion of legal problems

Question 7

Moral Model About Addiction being a brain disease

Answer 7

Addicts are people who CHOOSE drugs over work, family, and society due to their bad morals or weaknesses

Question 8

Medical Model About Addiction being a brain disease

Answer 8

Addicts suffer from a chronic brain disease, which can lead to difficulty in stopping use

Question 9

Studying drug use with animal models

Answer 9

Study causal effects
Ethical Limitations
Access to Additional Tools
There are many animal models, that isolate different behaviors associated with addiction
-Drug-taking
-Motivation for drug
-Resistance to punishment
-Craving and Relapse

Question 10

Common Animal Models

Answer 10

Conditioned Place Preference (CPP)
Conditioned Place Aversion (CPA)
Self-Administration

Question 11

Conditioned Place Preference/Aversion

Answer 11

Saline injection paired with one side
Drug injection paired on other side
On test day (drug free), where does animal spend time?
-

Question 12

Drug Self Administration

Answer 12

Animal performs an action (operant behavior) to receive a reward (drug infusion/sucrose pellet)
Can vary requirements for reward
-Fixed Ratio (FR) Schedules
-Drug-Taking
–Rate of Response
Ex: FR1-one response equals one reward
FR5-five responses equals one reward
-Progressive-Ratio (PR) Schedules (Drug-Seeking)
Motivation:
-Break Point
–Each subsequent reward requires an exponentially higher level of responses
-Can add punishment component
-Resistance to Punishment
–Foot Shock
–Each response results in a reward but is also paired with foot shock

Question 13

Is Self Administration Addiction

Answer 13

Not entirely due to unnatural circumstances
Usually single housed with minimal enrichment
No social interactions, toys, or stimulation
Self-administration sessions are the most interesting part of their day
Nothing in chambers to interact with except for the levers/nose ports
The animal can sleep or administer drugs

Question 14

Drug-Taking

Answer 14

Self-administration of drug of their own volition

Question 15

Drug-Seeking

Answer 15

Compulsively seeking drugs even when they are not available

Question 16

Resistance to Punishment

Answer 16

Responding even when drugs are paired with painful stimuli

Question 17

Increased drug motivation

Answer 17

Exerting more effort to obtain drug over time

Question 18

Relapse

Answer 18

Taste of drug or seeing cues can trigger relapse

Question 19

Role of Dopamine in Addiction

Answer 19

DA signaling from Ventral Tegmental Area (VTA) to Nucleus Accumbens (NAc) implicated in the rewarding effects of many rewards
Addictive drugs increase dopamine transmission from VTA to NAc

Question 20

How doe Dopamine promote drug-taking

Answer 20

Dopamine release is believed to be associated with pleasure. Many drugs enhance dopamine release and are therefore believed to be pleasurable.
Positive Reinforcement
During the negative state of withdrawal, dopamine release via drug taking relieves withdrawal symptoms
Negative Reinforcement

Question 21

Allostatic Model-Withdrawal Avoidance

Answer 21

Cessation of Drug use—Low DA levels—Low mood—Desire to boost mood/dopamine with drugs—Drug use and relapse

Support
-Withdrawal associated with low dopamine levels
-Many drugs increase mood and release dopamine
-Drug cues elicit negative mood, which can be alleviated by drug taking
Issues
-Relapse probability does not decrease after withdrawal has passed
-Drug cues enhances DA levels. They do not decrease them

Question 22

Anhedonia Theory

Support for it

Answer 22

Dopamine mediates the hedonic impact of rewards. Addicts just have unusually low levels of dopamine and use drug to increase them and the hedonic impact of rewards
Support:
-Addictive drugs produce euphoria
-Dopamine release enhanced by nearly all drugs of abuse
Issues:
-Dopamine is released before drug administration
-Dopamine is released in aversive situations
-Dopamine lesions/antagonists do not reliably block drug-induced euphoria
-Dopamine agonists do not reliably enhance hedonic reactions

Question 23

Affective reactions to various stimuli that can be objectively measured

Answer 23

Liking reactions to sweet taste
Disgust reactions to bitter taste
Appetitive eating behavior
Defensive fearful behavior

Question 24

Does dopamine cause pleasure

Answer 24

Liking reactions are not abolished after dopamine lesions or altered with amphetamine administration

Question 25

Incentive Sensitization

Answer 25

Drugs produce pleasure, but it isn’t driving addiction
-Drugs and drug cues releasing dopamine cause excessive “wanting” (craving, desire)
-Drug cues are powerful
-Drugs and drug cues gain incentive salience
-Wanted can be separated from liking
Drugs cause excessive wanting by:
-Promoting sensitization of dopamine system
-Cue-drug associations can be learned
-Gain incentive salience themselves
-This causes uncontrollable wanting of drugs not necessarily liking
This explains why relapsing is so common and can happen decades later
-Modifications to dopamine system result in long lasting changes. It is sensitized. May not like drug, but want it.

Question 26

Psychomotor Sensitization

Answer 26

Direct test of capacity of drugs to produce incrementally increasing behavioral changes. Indirectly models the addictive process.
Associated with motivational sensitization

Question 27

Incentive Sensitization

Support and issues

Answer 27

Support:
-Craving happens before withdrawal
-Craving induced by drug use itself
-Even drugs with small withdrawal are highly addictive
>Amphetamines, cocaine
-Nicotine is highly addictive, not very euphoric
-Dopamine depletion does not affect liking
Issues:
-Chronic drug use is sometimes associated with low dopamine levels
-Not clear why sensitization causes excessive wanting of drugs and not all things

Question 28

Why are sex differences important

Answer 28

Historically the therapies that have been developed from male data
There are sex differences:
-Drug taking
-Drug effects
-Motivation
Important to develop therapies based on differences