Substance Use Disorder Flashcards
What is substance misuse disorder?
Maladaptive pattern of substance use
What is dependence?
Inability to feel ‘normal’ without using substance
What is addiction?
Compulsive substance use to achieve reward stimuli, despite negative effects
What are the most commonly used substances?
- Cannabis
- Cocaine
- Ecstasy
- Alcohol
What substances are part of substance misuse disorder?
Alcohol
CNS depressants
CNS stimulants
Hallucinogens
What are the subtypes of substance misuse disorder?
low-risk use, hazardous substance use, harmful substance use, and substance dependence
What does substance dependence require?
AT LEAST 2 of:
- Impaired control over substance use
- Increasing priority over other aspects of life or responsibility
- Psychological features suggestive of tolerance and withdrawal
What areas of the brain does substance misuse affect?
specifically the basal ganglia, amygdala, and prefrontal cortex
What neurotransmitters does substance misuse affect?
Balance between glutamate, GABA and dopamine.
What happens when an individual consumes a substance (pathophysiology)?
- Affects the mesolimbic dopamine system in the nucleus accumbent and dorsal striatum in the basal ganglia.
- The release of dopamine gives off pleasurable feelings which trigger the reward system and positively reinforce the behaviour of substance consumption.
- This process is known as operant conditioning and is the basis of addiction and cravings.
- Some substances (eg. alcohol, opioids) interact with the inhibitory neurotransmitter GABA, which disrupts the equilibrium between GABA and glutamate.
- When an individual consumes substances, this disrupts the equilibrium as there are more sedative hormones (GABA).
- When exposed chronically, this results in neuroadaptation.
- The brain will upregulate the natural stimulants to achieve equilibrium.
- Withdrawal symptoms occur when there is a sudden drop in GABA, resulting in disrupted homeostasis and too much glutamate.
- The excess natural stimulants lead to withdrawal symptoms such as anxiety, sweating, and shaking.
What does continued consumption of substance cause?
Tolerance
- Receptors become less sensitive or neurons have fewer receptors (down regulation)
- Must consume more of substance to feel same effect
What does stopping substance use cause?
Withdrawal
- Body protectively counters consumption sx (so if there is no consumption, there is nothing to counter)
- So pts have to consume to voice discomfort (negative reinforcement)
May have fatal complications (eg. cancer, heart attack, OD)
What are signs and sx of substance use disorder?
- Tolerance
Withdrawal
- Anxiety, depression, irritability
- Fatigue
- Palpitations
- Clammy skin, sweating
- Dilated pupils
- Difficulty sleeping
- Vomiting,
- Seizures
- Change in vital signs
How Is substance use disorder diagnosed?
TWO or more of:
- Consuming more of a substance than intended
- Inability to cut down
- Use takes up a lot of time
- Cravings
- Use affects responsibilities
- Using in spite of social problems caused
- Use replaces important activities
- Using in physically dangerous situations
- Using even if its worsens problem
- Tolerance
- Feeling withdrawal sx
Mild = 2-3 sx
Moderate = 4-5 sx
Severe = 6 or more sx
How is substance use disorder managed?
Medications
- To reduce cravings, mimic substance, or change its effects
Psychotherapy
- Eg. motivational interviewing, CBT, peer-support programs
What is the max alcohol consumption recommended?
14 units / week spread evenly across 3 days or more
What is hazardous drinking?
individual consumes more than 14 units of alcohol / week
What is harmful drinking?
when the pattern of alcohol consumption directly causes physiological complications and illnesses
What is alcohol dependence?
craving and tolerance of alcohol consumption despite the negative complications experienced.
What is alcohol use disorder?
Maladaptive pattern of alcohol consumption
How does alcohol tolerance develop?
GABA, glutamate, dopamine, serotonin receptors become less sensitive/neurons have fewer receptors (downregulation)
Must drink more to feel euphoric (positive reinforcement)
Is alcohol a stimulant or depressant?
Depressant