Substance Abuse and Addiction

What are Psychoactive Drugs to a Pharmacologist?

Either a chemical not naturally found in the body or a body chemical administered in a larger dose than normal to the body, administered with the intent of producing a change in behaviour

What are Psychoactive Drugs to Le Dain Commission?

Any substance, natural or synthesized, that by its chemical nature alters structure or function of the body or mind in the living organism.

What are Psychoactive Drugs to the Canadian Parliamentary Special Committee on Non-Medical Use of Drugs?

A substance that, when ingested, alters mental processes such as cognition or affect

What is an Addiction?

A bio-psycho-social phenomenon; a multi-faceted process of drug dependency

What is Physical Dependency?

A physiological state of cellular adaptation that occurs when the body becomes so accustomed to a drug that it can only function normally when the drug is present

What is Psychological Dependency?

May range from a mild wish to a compelling emotional need for periodic or continuous use of a drug, such as an individual believing they cannot manage without a substance, and may escalate to feelings of loss or desperation if the drug is unattainable

Continuum of Use

Non-Use, Experimental Use, Occasional Use, Regular Use, Harmful Involvement, Substance Use Disorder

10 Types of Substance-Related Disorders according to the DSM-5

1. Alcohol, 2. Caffeine, 3. Cannabis, 4. Hallucinogens, 5. Inhalants, 6. Opioid, 7. Sedatives (Hypnotics or Anxiolytics), 8. Stimulants, 9. Tobacco, 10. Other or unknown

The 10 Types of Substance-Related Disorders fall into 4 Main Categories

Impaired Control, Social Impairment, Risky Use, Pharmacological Indicators (tolerance and withdrawal)

A problematic pattern of alcohol use leading to clinically significant impairment or distress as manifested by at least 2 of the following, occuring within a 12 month period

1. Alcohol is often taken in larger amounts or over a longer period than was intended. 2. There is a persistent desire or unsuccessful efforts to cut down or control alcohol use. 3. A great deal of time is spent in activities necessary to obtain alcohol, use alcohol or recover from its effects. 4. Cravings, or a strong desire or urge to use alcohol 5. Recurrent alcohol use resulting in a failure to fulfill major role obligations at work, school or at home 6. Continued alcohol use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effect of alcohol 7. Important social, occupational or recreational activities are given up or reduced because of alcohol use. 8. Recurrent alcohol use in situations in which it is physically hazardous. 9. Alcohol use is continued despite knowledge of having a persistent or recurrent physically or psychologically problem that is likely to have been caused or exacerbated by alcohol. 10. Tolerance, as defined by either of the following: a need for markedly increased amounts of alcohol to achieve intoxication or desired effects; a markedly diminished effect with continued use of the same amount of alcohol. 11. Withdrawal, as manifested by either of the following: The characteristic withdrawal syndrome for alcohol; Alcohol (or closely related substance, such as a benzodiazepine) is taken to relieve or avoid withdrawal symptoms.

Neurophysiology & Brain Development

1. Neurons communicate through chemical messengers called neurotransmitters 2. Neurotransmitters cross tiny gaps known as synaptic clefts 3. Brain development continues into the mid-20s, especially in the frontal lobes 4.Adolescents are more vulnerable to substance-related brain changes because their brains are still developing 5. Substance use during development can alter normal brain maturation.

Dopamine activity in the mesolimbic dopamine system and nucleus accumbens is central to what?

To reward and addiction

Repeated drug use causes long-lasting changes in brain circuits related to what do these brain changes contribute to?

Pleasure, Motivation, Memory, Judgment, Self-control.

These brain changes contribute to the development and persistence of addiction

Which Neurotransmitters are Important?

Dopamine, Endocannabinoids, Endorphins, GABA, Glutamate, Norepinephrine, Serotonin, Acetylcholine

Importance of Dopamine

Produces feelings of pleasure, reward, motivation, and euphoria. Most addictive substances increase dopamine activity.

Importance of Endocannabinoids?

Help regulate mood, sleep, appetite, pain, and memory. Cannabis affects this system through THC.

Importance of Endorphins

The body’s natural pain-relieving chemicals. Opioids mimic endorphins, reducing pain and increasing feelings of euphoria

Importance of GABA

The brain’s main inhibitory neurotransmitter. It helps reduce anxiety and slow brain activity

Importance of Glutamate

The brain’s primary excitatory neurotransmitter. It plays a major role in learning and memory.

Importance of Norepinephrine

Involved in alertness, stress responses, and the fight-or-flight reaction.

Importance of Serotonin

Regulates mood, sleep, appetite, impulse control, and emotional well-being

Importance of Acetylcholine

Important for memory, learning, attention, and muscle movement.

What is the study of Pharmacodynamics?

What drugs do to the body

What are 2 important concepts of Pharmacodynamics?

Tolerance, Withdrawal

Tolerance

Over time, a person needs more of a drug to achieve the same effect because the body adapts

Withdrawal

Physical and psychological symptoms that occur when drug use stops after dependence has developed

Pharmacodynamics

What drugs do to the body

2 Important concepts of Pharmacodynamics

Tolerance, Withdrawal

Tolerance

Over time, a person needs more of a drug to achieve the same effect because the body adapts

Withdrawal

Physical and psychological symptoms that occur when drug use stops after dependence has developed

Pharmacokinetics

What the body does to a drug

3 Critical Steps of Pharmacokinetics

1. Administration (how the drug enters the body) 2. Distribution (how it travels through the bloodstream) 3. Metabolism and elimination (how it is broken down and removed)

Routes of Administration

Distribution

Psychoactive drugs must cross into the brain to produce effects; Drugs that are highly lipid (fat) soluble enter the brain more easily

Metabolism

Liver metabolizes drugs. It is the body's primary detoxification organ. 

Elimination

Kidneys eliminate most drugs through: urine, feces, lungs/breath (some substances), sweat, saliva, breast milk

Half-Life

How drugs are often metabolized, the time required for the concentration of a drug in the blood to decrease by 50%, understanding a drug’s half-life helps determine dosage and duration of effects

What is the Drug Wheel?

It’s a classification model that groups different types of drugs based on the effect they have on the body and has 7 different categories.

7 Categories of the Drug Wheel

Empathogens, Stimulants,