Drugs of Dependence and Antidepressants Flashcards
What is drug dependence?
Drug taking becomes compulsive
Takes precedence over other needs
What is drug abuse?
Use of illicit substances or illicit use of legal substances
Recurrent and clinically significant adverse consequences
What contributes to psychological dependence?
Rewarding effect of psychoactive drug
What is the rewarding effect of the psychoactive drug?
Positive reinforcement > desire to continue experience
Does the rewarding effect only happen with drugs?
No, it can happen with any activity
What contributes to physical dependence?
Habituation/adaptation
What is habituation/adaptation?
Feeling normal/aversion of negative symptoms
Don’t take drug to feel good but not to feel bad
What are the reward and salience circuits involved in drug abuse and addiction?
Nucleus accumbens
Ventral pallidum
What are the memory and learning circuits involved in drug abuse and addiction?
Hippocampusw
Amygdala
What are the motivational drive circuits involved in drug abuse and addiction?
Orbitofrontal cortex
Subcallosal cortex
What are the inhibitory control circuits involved in drug abuse and addiction?
Prefrontal cortex
Anterior cingulate gyrus
What happens to the inhibitory control circuits in drug abuse and addiction?
Removed to elicit excitation
Which circuits have interplay between them in drug abuse and addiction?
Those for reward and salience, and memory and learning
Which neurotransmitter is implicated in reward pathways, and how?
Increased dopamine in nucleus accumbens
What are the key transmitters modulating dopaminergic transmission?
Atch Serotonin NA GABA Glutamate Opioids
Which neurotransmitters are targeted by most of the drugs that are used and abused?
Those that modulate dopaminergic transmission
Describe the dose-response curve in the CNS
Bell-shaped rather than sigmoid
What effects did cocaine have on people with high dopamine receptor levels?
Aversive effects
What effects did cocaine have on people with low dopamine receptor levels?
Pleasant effects
Do receptor levels change, and if so, what do they change in response to?
Yes, change in response to
- Time
- Disease
- Drug taking
How do some tolerance mechanisms work when receptors are involved?
Receptor levels are too high, so with extended drug use, they’ve been downregulated
What are two examples of opioids?
Morphine
Heroin
What are the CNS effects of opioids?
Euphoria
What are two examples of CNS depressants?
Alcohol
Diazepam
What are the CNS effects of CNS depressants?
Reduced anxiety
What are three examples of CNS stimulants?
Cocaine
Amphetamine
MDMA
What are the CNS effects of CNS stimulants?
Excitement
Euphoria
Reduce fatigue
What is an example of an hallucinogen?
LSD
What are the CNS effects of hallucinogens?
Altered perception
What is an example of a cannabinoid?
D-9-THC
What are the CNS effects of cannabinoids?
Altered perception
What is non-therapeutic drug use?
Consumption by choice not medical advice
What are the specific effects of CNS stimulants on CNS transmission>
NA, dopamine, and serotonin to various degrees
What does cocaine do at the synapse?
Block neuronal uptake of NA
What does amphetamine do at the synapse?
Utilises uptake carrier for NA to enter pre-synaptic terminal
Displaces NA from synaptic terminal
What effect do cocaine and amphetamine have on NA at the synapse?
Increase NA levels in synaptic cleft
Which neurotransmitters are predominantly affected in the CNS by cocaine and amphetamine?
Dopamine
Serotonin
Which neurotransmitters does amphetamine release in the CNS?
Predominantly NA and dopamine
Also serotonin