🤯Psychiatry🤯 - Substance Use & Addiction Flashcards
Give examples of drugs that may be abused
Alcohol - most commonly abused psychoactive drug
Nicotine
Cannabis
Stimulants e.g. amphetamines, cocaine, ecstasy
Opioids (can be prescribed, OTC) - heroin, fentanyl, morphine, DF118
Ketamine
Psychedelics e.g. LSD, magic mushrooms
What are the reasons that people use drugs for recreational use?
Positive reinforcement - gaining a positive state
-Escapism
-Get high
-Stay awake
-Like it
Negative reinforcement - avoiding a bad/adverse effect/state
-Boredom
-Reduce anxiety
-To help sleep
-Feel better
Other reasons
-Why not?
-Fit in
-Curious
What is the “like, want, need” model for drug misuse and addiction?
Note arrow goes both directions on first 2 stages
What diagnostic criteria is used for dependence syndrome?
ICD-10 diagnostic criteria
What is the ICD-10 criteria for dependence syndrome?
Strong desire or sense of compulsion
Difficulties in controlling substance taking behaviour in terms of its onset, termination, or levels of use
Physiological withdrawal state when substance use has stopped or been reduced
Evidence of tolerance: need to take more to get same effect
Progressive neglect of alternative interests
Persisting with substance use despite clear evidence of overtly harmful consequences
What is addiction vs dependence?
Addiction - compulsive drug use despite harmful consequences, characterized by an inability to stop using a drug; failure to meet work, social, or family obligations; and, (depending on the drug) tolerance and withdrawal
Dependence - refers to a physical adaptation to a substance
Tolerance/withdrawal
Eg opioid, benzodiazepine, alcohol
So can be dependent and not addicted
What characteristics of a drug affects its onset?
Speed of reaching the brain (method of intake) and time to cross blood-brain barrier (lipophylic)
What is the biochemical effect of alcohol in the brain?
Alcohol alters the balance between the brain’s inhibitory and excitatory system
How does excessive alcohol intake lead to a withdrawal state?
Chronic alcohol exposure results in neuroadaptations so that GABA & glutamate remain in balance in presence of alcohol
How does excessive alcohol lead to dependency?
What chemical is responsible for “reward”, and where is it found?
Dopamine
Found in the ventral striatum
Addiction - conceptualised as a “reward deficient” state
How do different substances of abuse interact with the dopamine signalling pathway?
How are “blunted responses” to anticipation of a reward and relapse related?
Abstinent addicts show blunted activation of reward system in anticipation of a drug “reward”
Correlation between reward pathway activity and likelihood to relapse
Describe the change from positive to negative reinforcement as addiction/dependence develops
