Lecture 1: Concepts in drugs of abuse

Question 1

What are the 5 types of psychoactive drugs?

Answer 1

1. CNS stimulants
2. Hallucinogens
3. CNS Depressants
4. Analgesics
5. psychotherapeutics

Question 2

What are four examples of analgesic drugs?

Answer 2

these are painkillers

1. morphine
2. codeine
3. heroine
4. methadone

Question 3

what are four examples of CNS depressant drugs?

Answer 3

1. barbituates
2. alcohol
3. sedatives
4. inhalants

Question 4

What are four examples of CNS stimulant drugs?

Answer 4

1. amphetamines
2. Cocaine
3. nicotine
4. caffeine

Question 5

What is the definition of drug abuse?

Answer 5

use of a substance in a manner, amount or situations such as the drug use causes problems, or greatly increases the chance of problems occurring… i.e. problems in the realm of legal, occupational or relationship problems

Question 6

What are the three C’s to addiction?

Answer 6

Consequences –> even though drug use has negative consequences, the person still uses it
Control (loss) –> inability to stop or use less, even if the user wants to
Compulsive –> always seeking and needing the drug and the abuse

Question 7

What are the two things that are measurable in an addiction to see how addictive a drug is or a person is?

Answer 7

Tolerance and dependence are the two components of an addiction that classify it as an addiction

Question 8

How are tolerance and dependence related? What factor links tolerance and dependence together?

Answer 8

Tolerance –> you can take more of the drug without feeling an effect or… you need more the drug to get the SAME effect
Dependence –> physically or psychologically unwell when you’re not taking the drug. Functioning is impaired without drugs

Tolerance can cause dependence and dependence can cause tolerance but what happens in between is adaptation
Adaptation is the changes in NT pathways and other physiological pathways to maintain homeostasis… when you take drugs too often or if the drug causes rapid changes, your body picks a new homeostasis which involves the drug and without it,your body feels as if it is not balanced and not healthy so it requires you to take the drug more.

Question 9

What are three types of tolerance?

Answer 9

1. Drug diposition/metabolic tolerance
2. behavioural tolerance
3. pharmacodynamic tolerance

Question 10

What is drug diposition/metabolic tolerance?

Answer 10

Chronic use of some drugs resulting in increased metabolism and excretion
- this is due to the increased activity or level of enzymes in the liver that are made more in order to detoxify the body of the drug (i.e. CYP2E1 and catalase upregulation in chronic alcoholics

Question 11

What is behavioural tolerance?

Answer 11

when you learn to compensate for impairment due to drugs

i.e. masking impairment and high functioning alcoholics

Question 12

what is pharmacodynamic tolerance?

Answer 12

it is the sensitivity of neurons to the drug changes

• this is usually presented in changes in receptors for NT’s or transporters for NT’s
• this is responsible for many withdrawal effects
• You can develop tolerance without becoming dependent in some drugs like antihistamines..etc..

Question 13

What is dependence?

Answer 13

state that occurs after using a drug so frequently and consistently that it is difficult for a person to function without the drug

can be presented as physical, psychological or both

Question 14

What are two types of dependence?

Answer 14

1. physical dependence

2. psychological dependence

Question 15

what is physical dependence?

Answer 15

when the drug physically alters the brain (i.e. when you’re taking antidepressants, the brain will upregulate excitatory pathways to compensate due to pharmacodynamic tolerance)

when drug use stops, the changes that occured in the brain can result in withdrawl symptoms such as seizures when you come off antidepressants

withdrawal symptoms result in the opposite effect of the drug causes

i.e. stimulant drugs result in lethargy when coming off of them
and heroine causes diarrhea (because it causes constipation when you’re on it)

Question 16

What is psychological dependence?

Answer 16

drugs that are reinforcing (stimulates the reward pathway when the act of taking them occurs)

this manifests as a compulsion or perceived need for use

development of psychological dependence is also linked to changes in the brain in response to drug use (physical changes)

this is accepted to be the real force behind drug abuse rather than physical dependence

Question 17

What are some examples of psychological symptoms that result from absence of drug?

Answer 17

craving, anxiety, panic, obsession with the drug, relapse

Question 18

what are some examples of physical symptoms that result from absence of drugs?

Answer 18

illness,physical symptoms

withdrawal symptoms

Question 19

What is an example of drug abuse not resulting in tolerance or dependence?

Answer 19

binge drinking

is defined as drinking five or more drinks or male and four or more for female in one sitting per month

leads to increased risk of harm

and occurs so infrequently that CNS and liver do not adapt

Question 20

What are some accute effects of drug abuse?

Answer 20

these effects happen immediately or soon after drug is taken

• high and euphoria
• arises from rapid rise in dopamine levels in the nucleaus accumbens which is part of the reward pathway
• all drugs increase dopamine levels but in different ways
  (i. e. prevent DA from being removed from the synaptic cleft)

Question 21

What are some chronic effects of drug abuse?

Answer 21

these are long term effects
- sturcutre and function of the brain changes (neuroplasticity)
these changes over time cause addiction/dependence/ and tolerance
communications between parts of the Nucleaus accumbens and reward pathway is altered (ie. communication with the prefrontal cortex and the reward pathway is altered causing poor judgements and decisions)