Lecture 2: Intro To Psychopharmacology Flashcards
What is psychopharmacology?
- the study of drugs effect on mood, perception, cognition, & behaviour
- pharmacology and psychology
- focuses on psychoactive drugs
What are psychoactive drugs?
- Drugs that effect the CNS (brain and spinal cord)
- changes in the function and sometimes the structure of our brain
- PET scan: functional, show where molecules bind (give mildly radioactive substance, will bind in some places [radioactive cocaine, binds more weakly in long-term substance users.. isn’t directly binding to some areas
Psychopharmacology
How drugs affect our mood/perception/behaviour/cognition; how they affect our CNS
Behavioural pharmacology
From behaviourism
Starts out of how drugs affect behaviour
Often some aspect of operant/classical conditioning (Pavlov, animal models)
Neuropsychopharmacology
The study of how drugs affect the nervous system and how these nervous system changes alter behaviour
Why is psychopharmacology important?
- drug use is ubiquitous
- billion of ppl use psychoactive drugs daily; anti-depressants; coffee; alcohol
- field provides insight into human behaviour
- push the system in one way or another; make an inference on how healthy human/animal brain functions
- addiction is prevalent
- our solutions are currently unsatisfactory
- need better solutions to keep ppl safe
What is a drug?
“An administered substance that affects physiological functioning.”
Problem with drug definition
1) administered
2) affects physiological functioning
“Administered”
Administered: some substance, if they are not administered, they are not a drug – testosterone in our bodies = not a drug, simply a hormone (pill/cream/injection = drug)
Many experiences are administered: walk in nature, will affect our physiological functioning
Dopamine: inside your body, is simply a neurotransmitter – outside your body, considered a drug
“Affects physiological functioning”
Affects physiological functioning: does water do this? Yes
(food, vitamins, nutritional supplements – not considered drugs, yet they all affect physiological functioning)
Exogenous
From outside the body
Endogenous
From within the body
Why are drugs used?
Instrumentally and recreationally
Instrumentally
o Using the drug to accomplish some sort of specific purpose
In the morning, drink coffee to wake us up
Drinking alcohol to relieving stress
Taking drug to avoid withdrawal – instrumental
Recreational drug use
o Using a drug for the sole purpose of experiencing the substances effects
Drinking alcohol in a recreational way to party and have fun
Xanax (prescription drug) used recreationally, to experience the effects
Historically have a problem with doing things fun; often a push to legalize cannabis – marketing shift towards medical marijuana – reframing for instrumental use, important part of legalization (advocating for instrumental drug use)
Trade name
Often a marketing skew, not based on anything
- viagra (sounds vital)
Generic names
Chemistry might be incorporated
- sildenafil
Chemical names
Gives complete detail of the chemical structure of a drug
- 5-{2-(ethyloxy)-5-[4-methylpiperazin-1-yl)sulfonyl]phenyl}-1-methyl-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one
Street name
Name used by those who take/sell the drug for the streets
- blue diamond
Dose
o Higher dose = more of the drug, but how much for what person?
o Amount of drug, per body weight
o Milligram per kilogram / microgram per kilogram
o Drug study with rats: rats must be weighed before the drug is administered
Dose-effect/dose-response curve
o Lower doses, we might not see the effect – want a higher effect
o Scatter plot; draw line of best fit through
o X axis
Increasing dose
o Y axis
Number of individuals responding to the drug
How strong the effect is felt
o Have to give the drug in different doses; multiple times over different sessions (commonly 3 different doses)
o Have to be based on experimental data; real world phenomenon
ED 50
o Median effective dose
o The dose where 50% of the effect was observed or when the effect was observed in 50% of participants
o To find: need to draw it in, from the right
o Only experimentally derive; collecting data in the world
o Effect? Effect is arbitrary
Supposed to change our mood? How did the mood change? Can vary Sometimes there may be many effects; may separate these
Potency
o Some drugs are more potent than others
o Potent = stronger
o If one drug is more potent than another, the more potent drug’s graph will be shifter to the left (take less dose); if a drug is less potent, the graph will be shifted to the right
TD50
o Median toxic dose; typically far to the right
o Dose at which 50% of the subjects experience a toxic effects or when the toxic effects are experienced 50% of the time
o Studies done on animals
Therapeutic index
TD50/ED50
o Mathematical equation
o Doesn’t tell you a lot; if you have 3 different drugs – can compare
o Greater = margin of safety is larger
o Is not conservative
Certain safety index
o Mathematical calculation
o We want to know when anyone has a toxic effect – care about TD1 more, do not want anyone to feel the adverse effects if possible
Where 1% experience toxic effects
o Want everyone to have the benefits of the drugs, where 99% of the effect is there or 99% experience the effects
o More conservative – certain safety index
o Certain safety index larger (1 vs 7) = 7 is safer, ED is farther from TD
LD50
o Median lethal dose; where 50% of individual die at that dose
o To make sure the public is safe
Pharmacodynamics
o The physiological actions of the drugs; the actual mechanism
o Bind to glutamate receptor? What change does it cause?
Pharmacokinetics
o How drugs are passing through our body
o Administered; stored; do they break down? Pass to the brain undisturbed? Metabolized the in the liver?
o How are they eliminated from the body? Exhaled? Through the urine?
Pharmacogenetics
o How differences in our genes, lead to differences in our biological makeup/pharmacodynamics and pharmacogenetics
o Some can tolerate drugs better, more/fewer of an enzyme
Psychoactive drug effects
- objective
- subjective
Objective effects
o Drug effects that we are capable of directly measuring
o How does it change heart rate, salivary production, pupil dilation?
Subjective effects
o Drug effects that can’t be directly observed
o Affects our memory – have to study indirectly, memory test
How do we acquire info about the world
- authority
- intuition
- observation
- test
