1
Drugs and Addiction 2021
HC1: Course introduction
Basic questions:
How many Europeans have ever used illicit drugs? 25%
Dependence to which drug can NOT be treated by pharmacotherapy?
- Alcohol?
- Cocaïne? → yes.
- Heroin?
- Nicotine?
What is mephedrone? Synthetic stimulant drug (NPS).
What is the street price of 1 gram heroin? Heroin is not so popular as a drug. €50
How many XTC pills are you allowed to possess in NL? 1
Which drug do you consider most dangerous? Crystal meth, heroin, alcohol.
Defining characteristics of drug addiction:
- Tolerance = neuroadaptations induced by repeated drug use, resulting in a decrease
in the reinforcing properties of the drug.
- Craving = intense urge to consume drugs.
- Euphoria = pleasurable sensations induced by drug use.
- Problems with law enforcement
- Loss of control
- Desire to quit
- Withdrawal (symptoms) = intense and unpleasant symptoms occurring when drug
use is discontinued.
- Relapse = reinstatement of drug use after a period of abstinence.
Brief definition:
A substance-related psychiatric disorder characterized by
● A persistent loss of control
● Obsessive craving
● Chronic relapse
NB: Tolerance and withdrawal can occur, but relapse is not necessarily associated with
these phenomena.
Drug-centered views on addiction:
● Negative reinforcement theory.
● Positive reinforcement theory.
● Neuroadaptation theory.
Negative reinforcement theory (anhedonia)
PRO
+ Drugs can be used to alleviate pain and symptoms of anxiety and depression.
, 2
+ Drug use abolishes the withdrawal symptoms, thereby maintaining drug-taking
behavior.
CON
- Feelings of anhedonia do not necessarily explain drug use.
- Drug use can be continued in the absence of withdrawal symptoms.
- Alleviating withdrawal signs by means of pharmacotherapy does not prevent relapse.
- Relapse can occur long after withdrawal signs have dissipated.
Positive reinforcement theory (euphoria)
PRO
+ Drug of abuse induce euphoria and are therefore addictive.
+ Because of these euphoria-inducing effects drug-taking behavior is maintained.
CON
- NO clear relationship between the euphoria-producing effects of drugs and their
abuse potential (cf. tobacco).
- The long-term negative consequences of drug use (e.g. on health and well-being)
definitely outweigh the short-lasting euphoria, yet drug use is not discontinued in
addicts.
Neuro-adaptation model
Definition:
● Structural and functional adaptations in the brain induced by repeated drug use
underlie addictive behavior.
● The brain’s reward system becomes sensitized to drugs and drug-associated stimuli.
These stimuli lead to intense feelings of drug craving.
In addition:
● Continued drug use impairs prefrontal cortical function.
● Drug use becomes compulsive and inflexible.
The downward spiral of drug addiction:
, 3
Summary:
Drug addiction:
● is a multifaceted disorder.
● is a process, rather than a state.
● is considered as a disorder of the brain.
Ecstasy use in England, interesting video clip:
https://video.vice.com/nl/video/the-truth-about-ecstasy-high-society/57e1350cb8298923b2c1
d145
HC2: Neurobiology of addiction
Learning goals:
1. Understand how and why the brain responds to addictive/abuse drugs.
2. Analyze the steps that lead to addiction.
- Know why so many people use drugs.
- How these drugs affect the brain functionality.
- What are their specific mechanisms of action?
- Which are the short and long-term effects.
The 5 pillars to understand the neurobiology of addiction
Pillar 1. Everything we like leaves its fingerprints in the brain.
a. The limbic systems is about emotions
, 4
b.
i. Important for:
1. Emotional control and emotional memories.
2. Reward and reward memories.
c. Limbic system activation = REWARD!
d. Example: What would you do when you are starving?
As all begins… Limbic systems and pals
● How does the limbic system regulate motivated behavior and reward?
Drugs and Addiction 2021
HC1: Course introduction
Basic questions:
How many Europeans have ever used illicit drugs? 25%
Dependence to which drug can NOT be treated by pharmacotherapy?
- Alcohol?
- Cocaïne? → yes.
- Heroin?
- Nicotine?
What is mephedrone? Synthetic stimulant drug (NPS).
What is the street price of 1 gram heroin? Heroin is not so popular as a drug. €50
How many XTC pills are you allowed to possess in NL? 1
Which drug do you consider most dangerous? Crystal meth, heroin, alcohol.
Defining characteristics of drug addiction:
- Tolerance = neuroadaptations induced by repeated drug use, resulting in a decrease
in the reinforcing properties of the drug.
- Craving = intense urge to consume drugs.
- Euphoria = pleasurable sensations induced by drug use.
- Problems with law enforcement
- Loss of control
- Desire to quit
- Withdrawal (symptoms) = intense and unpleasant symptoms occurring when drug
use is discontinued.
- Relapse = reinstatement of drug use after a period of abstinence.
Brief definition:
A substance-related psychiatric disorder characterized by
● A persistent loss of control
● Obsessive craving
● Chronic relapse
NB: Tolerance and withdrawal can occur, but relapse is not necessarily associated with
these phenomena.
Drug-centered views on addiction:
● Negative reinforcement theory.
● Positive reinforcement theory.
● Neuroadaptation theory.
Negative reinforcement theory (anhedonia)
PRO
+ Drugs can be used to alleviate pain and symptoms of anxiety and depression.
, 2
+ Drug use abolishes the withdrawal symptoms, thereby maintaining drug-taking
behavior.
CON
- Feelings of anhedonia do not necessarily explain drug use.
- Drug use can be continued in the absence of withdrawal symptoms.
- Alleviating withdrawal signs by means of pharmacotherapy does not prevent relapse.
- Relapse can occur long after withdrawal signs have dissipated.
Positive reinforcement theory (euphoria)
PRO
+ Drug of abuse induce euphoria and are therefore addictive.
+ Because of these euphoria-inducing effects drug-taking behavior is maintained.
CON
- NO clear relationship between the euphoria-producing effects of drugs and their
abuse potential (cf. tobacco).
- The long-term negative consequences of drug use (e.g. on health and well-being)
definitely outweigh the short-lasting euphoria, yet drug use is not discontinued in
addicts.
Neuro-adaptation model
Definition:
● Structural and functional adaptations in the brain induced by repeated drug use
underlie addictive behavior.
● The brain’s reward system becomes sensitized to drugs and drug-associated stimuli.
These stimuli lead to intense feelings of drug craving.
In addition:
● Continued drug use impairs prefrontal cortical function.
● Drug use becomes compulsive and inflexible.
The downward spiral of drug addiction:
, 3
Summary:
Drug addiction:
● is a multifaceted disorder.
● is a process, rather than a state.
● is considered as a disorder of the brain.
Ecstasy use in England, interesting video clip:
https://video.vice.com/nl/video/the-truth-about-ecstasy-high-society/57e1350cb8298923b2c1
d145
HC2: Neurobiology of addiction
Learning goals:
1. Understand how and why the brain responds to addictive/abuse drugs.
2. Analyze the steps that lead to addiction.
- Know why so many people use drugs.
- How these drugs affect the brain functionality.
- What are their specific mechanisms of action?
- Which are the short and long-term effects.
The 5 pillars to understand the neurobiology of addiction
Pillar 1. Everything we like leaves its fingerprints in the brain.
a. The limbic systems is about emotions
, 4
b.
i. Important for:
1. Emotional control and emotional memories.
2. Reward and reward memories.
c. Limbic system activation = REWARD!
d. Example: What would you do when you are starving?
As all begins… Limbic systems and pals
● How does the limbic system regulate motivated behavior and reward?
