Class 9: Substance Use Disorders Flashcards
Define Drugs.
Chemical compounds that when administered produce a physiological change in the body.
Which type of drugs are most relevant in the context of substance abuse and addiction?
Psychoactive drugs which alter mood thought or behaviour.
How do most psychoactive drugs exert their effects?
By influencing chemical signaling in the synapse.
What are the three different categories of psychoactive drugs?
- CNS Depressants
- CNS Stimulants
- Hallucinogens
What do CNS Depressants do?
General suppression and relaxation (including suppressing mental function)
What do CNS Depressents do at low doses vs at high doses?
Low Dose: Calming
High Dose: Intoxication leading to sedation, coma or death
What do CNS Stimulants do?
Stimulate arousal giving a rapid but temporary boost of energy or clarity.
What do Hallucinogens do?
Alter perceptual experience; disturbing reality or cause hallucinations.
Name 3 Examples of CNS Depressants.
- Alcohol
- Opiates (Morphine, Heroin)
- Anxiolytics (Benzodiazepines, Barbiturates)
Name 4 examples of CNS Stimulants.
- Amphetamine (Meth, Speed)
- Cocaine
- Caffeine
- Nicotine
Name 3 Examples of Hallucinogens.
- Marijuana
- LSD
- MDMA (ecstasy)
What age group has the highest percent of alcohol drinkers?
Young adults (18-24) followed closely by adults (25+)
What age group has the highest percent of cannabis users?
Youth (15-24) followed by adults (25-44)
Is opioid use in Canada going up or down?
Down thanks to getting it prescribed less.
Define ‘problematic substance use’
When someone uses drugs or alcohol in a harmful way that has negative effects on their health and life.
Define Substance Use Disorder.
Uncontrolled use of a substance despite harmful consequences
Define Addiction
State of uncontrolled drug use that persists in spite of negative consequences
What are the 4 diagnosing categories of DSM-5 for Substance Use Disorders?
- Impaired Control
- Social Impairment
- Risky Use of Substance
- Pharmacological Criteria
Describe the ‘Impaired Control’ Category of Diagnosing Substance Use Disorders in 4 points.
- Substance taken in larger amounts or over a larger period of time than intended
- Persistent desire or unsuccessful efforts to cut down or control substance use
- Spends a great deal of time in activities necessary to obtain/use or recover from substance
- Craving or strong desire/urge to use substance
Describe the ‘Social Impairment’ Category of Diagnosing Substance Use Disorders in 3 points.
- Recurrent substance use resulting in failure to fulfill major role obligations at work/school/etc
- Continued substance use despite having persistent or recurrent social or interpersonal problems
- Important social, occupational, or recreational activities given up/reduced because of substance use
Describe the ‘Risky Use of Substance’ Category of Diagnosing Substance Use Disorders in 2 points.
- Recurrent substance use in situations which it is physically hazardous
- Substance use continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by substance use
Describe the ‘Pharmacological Criteria’ Category of Diagnosing Substance Use Disorders in 2 points.
- Tolerance, as defined by either:
a. a need for markedly increased amounts of substance to achieve intoxication OR
b. markedly diminished effects with continued use of the same amount of substance - Withdrawal as manifested by: characteristic withdrawal syndrome OR substance is taken to avoid withdrawal symptoms
How many critieria points do you need to be diagnosed with SUD (at each of the 3 levels) and for what timeframe
Mild: 2 to 3 Criteria
Moderate: 4 to 5 Criteria
Severe: 6 or more Criteria
within the last 12 months
Define Withdrawal
Physical and psychological behaviours that are displayed by an individual with a SUD when the drug use ends (several hours after to possibly several days)
Name 11 common symptoms of withdrawal.
Define Reward
Stimuli that are in some way desirable or positive and can ultimately affect behaviour
What is the main job of the reward pathway?
Make us perform actions that help us survive and to make it easier to do them again.
How can certain reward pathways (for example the reward of a delicious meal) be strengthened?
Repeated activation
What (fundamentally) happens in the brain in the reward pathway?
- Stimuli occurs
- Neurons in the reward pathway will release the NT dopamine
- Signals to motor center to make it easier to do this behaviour over and over
How was the reward pathway discovered?
Olds and Milner in 1954 took a rat. They put electrode in different areas of the brain and allowed the rat to activate that area themself. (intracranial self-stimulation ICCS). The rat ignored other stimuli and stimulated itself to exhaustion.
What is the official name of the reward pathway/circuit?
Mesocorticolimbic system
Where does the reward pathway start?
Ventral tegmental area (VTA)
What parts are involved in the Mesocorticolimbic Dopamine System?
- Ventral tegmental area (VTA)
- Hippocampus (Hipp)
- Nucleus Accumbens (NAc)
- Prefrontal Cortex (PFC)
What happens when dopamine is released to the NAc?
The feeling of subjective pleasure
What happens when dopamine is released to the Hippocampus?
Learned association between the rewarding feeling and the specific stimulus.
What happens when dopamine is released to the PFC?
Cognitive control necessary to seek/avoid the rewarding stimuli
Does every addictive drug affect the reward pathway?
Yes!
Do addictive drugs release more, less or around the same amount of dopamine as “natural” rewards?
Way more.
Why does the brain prioritize drugs over other pleasurable stimuli?
Because drugs give so much more dopamine the brain prioritizes it over the “lesser” rewards.
What makes cocaine very addictive?
Users are lured by the “rush” but since its effects are so short-lived, they tend to use the drug over and over again.
How long does it take for the cocaine rush when IV injected, Smoked, and Snorted?
Injected: 30s
Smoked: 30s
Snorted: 10-15 minutes
How long does it take for cocaine to leave the system?
2 hours.
How does cocaine affect the synapse?
Cocaine enters the brain and blocks the dopamine reuptake transporter resulting in dopamine accumulating in the synapse over-stimulating the mesocorticolimbic dopamine system
What two ways does tolerance to cocaine work in the synapse?
- Dopamine receptors are removed from the post-synaptic membrane
- Dopamine release from pre-synaptic terminal is reduced
Why can cocaine block dopamine reuptake transporter if they are supposed to be unique to their NT?
Cocaine is chemically similar to the dopamine molecule which allows it to ‘fit’ into the transporter just enough to get stuck.
