PSYC330

Māori Use of Psychoactive Substances

Before European arrival, Māori used psychoactive substances like Kawakawa and Pukatea primarily for medicinal purposes, not recreation.

Kawakawa, Pukatea, & Radula Marginata

The psychoactive substances that Māori used as medicines before the arrival of Europeans

date of introduction of Alcohol and Tobacco in Aotearoa

Europeans introduced alcohol and tobacco to New Zealand in the late 1700s

Maori Women’s tabacco use

while frowned upon by European women, Maori women began to use tobacco extensively in early 1800’s

The Maori Councils act 1900

let Maori councils prohibit the use of tobacco by children and to fine suppliers as they could see the harm it brought to their communities

smoking habits of Maori in the 1900s

Although the harms were recognized, the drug was already well established in the Māori communities

Smoking Rates 1962 in Maori

smoking rates were significantly higher among Māori (58% men, 70% women)

smoking rates 1963 in general NZ population

compared to the general population (38% men, 31% women).

Alcohol's Integration

Alcohol, initially not preferred by Māori, became integrated into their culture by the 1850s, leading to significant social problems recognized by early Māori doctors.

Waipiro

stinking water (alcohol described by early Maori)

dry areas

established areas where alcohol could not be consumed

Maori and non-Maori drinking patterns

maori consumed twice as much but drunk less frequently

Maori mortality and alcohol consumption

Maori are 2x as likley to suffer sever alcohol related problems and 4x as likeley to die of a condition caused or made worse by alcohol

opium smoking in 1860’s NZ

brought to NZ by Chinese miners

what were cannabis cigarettes advertised as in the 19th century?

a cure to asthma and insomnia

what drug control measures were taken in NZ?

New Zealand implemented various drug control measures from 1866 to 1965:

• Sales of Poison Act 1866 (label opium as poison)

• 1871 registration of opium (required registration of vendors)

• Opium Prohibition Act of 1901 (prohibited smoking and importation)

• Quackery Prevention Act 1908 (restrict patent medicines)

• Dangerous Drugs Act of 1927 (imported but had to be licensed)

• Misuse of Drugs Act 1975

what was heroin usage in NZ like (1940s)?

NZ had some of the worlds highest heroin use rates due to use of prescriptions.

Cannabis use in NZ

The 1960s saw a rise in cannabis use in New Zealand, influenced by cultural movements, with the country having one of the highest rates of cannabis use globally.

Misuse of Drugs Act 1975

This act aimed to align New Zealand's drug policies with international standards, establishing schedules for drugs based on their potential harm.

Classifications of Drugs

Drugs are classified into three classes (A, B, C) based on their risk of harm, with Class A being the most dangerous and illegal.

Class A drugs

• LSD

• heroin

• cocaine

• methamphetamine

• Psilocin & psilocybin

Class B drugs

• cannabis (oil)

• morphine

• amphetamine

• MDMA

Class C drugs

• Cannabis (plant/leaf/fruit/seed)

• barbiturates

• benzodiazepines

issues with the legislations for these drugs in each class?

alcohol is considered a class A drug but is not shown in this act, and the information is not evidence based for example LSD and Psilocin are some of the least harmful drugs known to man but they are considered class A drugs.

substance use burden in NZ

Substance use is a leading cause of disease burden in New Zealand, with significant economic costs associated with drug-related issues.

what is a drug?

a medicine or other substance which has a physiological effect when ingested or otherwise introduced to the body

DALY

a measure of overall disease burden, expressed as the cumulative number of years lost due to ill health, disability, or early death

amount spent on drug related costs per year

1.8 billion, 350 million on drug laws. mostly goes to criminal costs rather than rehabilitation.

does alcohol do more harm to self or to others?

others, but still a lot of harmful effects to the individual

do synthetic cannabinoids do more harm to self or others?

self because they are lab constructed rather than naturally occurring

what are different ways of naming a drug?

• chemical name - chemical composition

• generic name - lets you know what type of drug it is

• trade name - drug company develops it and can rename it

• street name- varies considerably

what is a drug dose and how is it decided upon?

The impact of a drug is related to its concentration in the body, with the dose often measured in mg/kg based on body weight.

what is a drug response curve?

a visual way to establish a picture of the effects of a drug.

what is ED50?

median effective dose- the dose that is effective in 50% of the subjects tested

what is LD50?

median lethal dose - the dose the is lethal in 50% of subjects tested

what is know regarding drug safety?

the further the distance between ED50 and LD50 the better. therapeutic index.

therapeutic index

an objective way to describe the safety of the drug. TI = LD50/ED50. the higher the TI the safer the drug.

two ways to describe the extent of a drugs effects

potency & effectiveness

what is drug potency?

differences in ED50 of the two drugs that have the same effect. e.g., a lower dose of A is more effective than a higher dose of B even though they have the same effect, think less is more.

what is drug effectiveness?

differences in the maximum effect that drugs will produce at any dose

primary vs side effects

primary effects are the intended result in treatment whereas side effects are the unintended effects.

Drug Interactions

Combinations of drugs can lead to additive effects, antagonism, or super additive effects, influencing their overall impact on the body.

in a drug interactions graph, a drug that is higher in potency will shift the dose-response curve towards the left or right?

left

additive effect

adding an addition drug and the effect it has on the original drug. The combination effect of two or more chemicals equal to the sum of the effect of each agent acting independently(additive). Shifts dose response curve to the left.

drug antagonism

one drug diminished the effect of the other, can decrease the potency and effectiveness. If you are taking a drug for a particular reason, anything else that occurs that is not the primary reason is considered a side effect, unintended.

super additive effect/potentiation

combining drugs increases the effect, need more of the first drug when another is added in order to achieve the effect of the original drug on its own. Drug that is being added is antagonising the effect of the 1^st drug.

what is pharmacokinetics and the three processes?

The study of how drugs are absorbed, distributed, and eliminated in the body, crucial for understanding their effects. includes absorption, distribution and elimination.

4 routes of administration

oral, inhalation, and intravenous, each affecting absorption and onset of action.

parental

injection under the skin

transdermal

absorbed through the skin, good if you want the drug to be absorbed slowly

vehicle

before a drug can be injected it must be a liquid

other routes of adminstration.

• Vehicle (before a drug can be injected it must be a liquid 

• Subcutaneous (needle inserted under the skin or cutaneous tissue

• Intramuscular (needle inserted into the muscle)

• Intraperitoneal (needle inserted into the peritoneal cavity) 

• Intravenous (needle inserted into the vein)

non-human/invasive routes of adminstration

• Intrathecal (inserted between the base of the skull and the first vertebra) Drug gets left in the CFS

• Intracerebroventricular (inserted directly in the brain’s ventricles)

• Intracerebral (inserted directly into brain tissue) often through cannula

Blood-Brain Barrier

A protective barrier that regulates which substances can enter the brain, influencing drug effects on the central nervous system. substances can not pass BBB if too highly charger, too large or not lipid soluble.

veins

carry blood to the heart

arteries

carry blood away from the heart and to the rest of the body

capillaries

permeate most body tissues, drugs move through capillaries into blood through diffusion.

lipid solubility and absorption

• all tissue in the body is composed of cells that form membranes

• in order to get inside the cell, drugs have to cross phospholipid bilayers

• drugs that can dissolve in fat (lipid soluble) are more readily absorbed

passive transport/diffusion

most basic and least efficient way “moving from areas of higher concentration to low concentration”. Does NOT require energy. Moves with diffusion gradient. Takes a long time.

Active transport

works against diffusion gradient, DOES require energy. Costly process.

placental barrier

similar to blood-brain-barrier. Drug concentration in the blood of the fetus reaches 75-100% of that in the mother in roughly 5 minutes. Drugs cross the barrier quite easily, very little protection for the fetes from drugs administered to the mother

Metabolism and Excretion

Drugs are metabolized primarily in the liver and excreted through the kidneys, with the rate of elimination often described by half-life. requires enzymes and uses catalysts that control chemical reactions.

what is half-life

the time it takes for the amount of a drugs active substance in your body is reduced by half. exception to this rule is alcohol (as alcohol is consumed in large quantities and saturates enzymes quickly).

First-pass metabolism

drugs are absorbed through the digestive system, passing through the liver first

what are some factors that alter drug metabolism?

• stimulation of enzyme systems & depression of enzyme systems. e.g., excess alcohol dehydrogenase in liver of heavy drinkers or disulfiram blocks aldehyde dehydrogenase (makes you sick if you drink it).

• age- enzyme production and function changes with age

• species - levels of certain enzymes differ between species

what is therapeutic window for drugs?

to be effective the right level of drug must be maintained in the blood for an extended period of time. Too much will produce side effects, too little will not produce the wanted therapeutic effect.

Tolerance and Sensitization

Tolerance refers to decreased drug effectiveness with repeated use, while sensitization is an increased response to a drug after repeated exposure.

Classical Conditioning

Drug effects can be conditioned, where environmental cues associated with drug use elicit responses similar to the drug's effects.

Operant Conditioning

The relationship between behavior and its consequences, where reinforcement influences the likelihood of a behavior being repeated.

Neurotransmitters

Chemicals that transmit signals in the nervous system, with various drugs affecting their release, reuptake, and receptor binding.

what did Jacques-Joseph Moreau do?

became interested in doing systematic analysis of the effects of weed on CNS. used himself and others as test subjects documenting results.

what took place as part of evolution science in the development and use of drugs?

• modern chemical techniques for synthesizing active chemical in drugs

• modern refinements in the study of behaviour

how can introspection be defined?

to observation of ones own mental and emotional processes.

who is John B Watson and what did he do?

felt that science, and psychology should study only observable behaviour rather than subjective behaviour. (behaviourist movement)

what did early studies of drugs on behaviour look like?

carried out by pharmacologists involved unstructured observations of lab animals after given drugs, monitored running, sleep, convulsions.

• if the drug increased locomotor activity, it was taken to indicate it as CNS stimulant.

• if drug decreased locomotor activity, it was taken as a CNS depressant

  however the same dose of the same drug can impact behaviour significantly depending on what occurs before the drug. (Dew pigeon study).

behavioural pharmacology

interactions between drugs, organisms and the environment

what is chlorpromazine and its purpose?

in 1951 it was synthesised, was considered useful for general anesthesia as it produced a cooling of the body temperature and disinterest without loss of consciousness. drug was taken by psychiatric patients had the ability to live a normal life.

what was chlorpromazine labelled as?

in 1952 it was marketed as an antipsychotic labelled Thorazine

Who was Peter Dew and what was his role in behavioral pharmacology?

studied effects of drugs on pigeons had then pecking for grain reinforcement in a operant chamber. after giving pigeons pentobarbital Dew measured change in responding that occur after the drug. trained the pigeons on different schedules (FR 50 and FI 15)

what were the results from Dew pigeon study?

comparatively FI-15 to FR-50 schedule produced a lower rate of responding

Who is Joseph V. Brady and what was his role in behavioral pharmacology?

Believed neuroscience could be useful in understanding the effect of drugs on behaviour. Also drugs and behavioural pharmacology research could tell us a lot about the function of the brain. Conducted important research on relationship between stress and ulcers, stress was a physical illness, producing physiological problems.

 

Fillmore and Vogel-Sprott (1992)

studied the placebo effect using coffee and performance task. no one got any caffeine, but expectations had an impact on behaviour.

what does a balanced placebo design consist of?

4 groups:

1. expect a drug, get a drug

2. Expect a drug, get a placebo

3. Don’t expect to get a drug, get a drug

4. Don’t expect to get a drug, get a placebo

three group designs used when a drug is undergoing a clinical trial

1. experimental drug

2. placebo

   1. established treatment (test new drug for its affects against an already established treatment)

what are the ratio schedules?

• Fixed ration (FR) = reinforcement delivered after fixed number of responses

• Variable ratio (VR) = reinforcement delivered after a specified average (slot machines)

what are interval schedules?

• Fixed interval (FI) = reinforcement delivered for the first response after a fixed amount of time has elapsed.

• Variable interval (VI) = reinforcement is delivered for the first response after an amount of time that varies around a specified average.

what is the avoidance escape task?

Animal can be taught to avoid/escape aversive stimuli.

Threat conditioning- chamber with two rooms/compartments in one you can deliver a CS (tone) teach animal to know that the sound may result in a shock. When the subject is given a shock, they then run out of compartment where they are safe Escape.

Pair CS with shock Leaving chamber when shock is on, they are escaping, leaving chamber when CS is on, they are avoiding.

Important distinction as it has to do with a lot of aspects of anxiety disorders. Sensitive screen for antipsychotic drugs working in people. blocks the ability to avoid shock but not the ability to escape.

discrimative stimulus

a stimulus in the presence of which a specific response will be reinforced. For example, stop sign is a stimulus to tell you that in the presence of the stops sign, if you don’t stop you might get a ticket. Stop sign is a discriminative stimulus in the presence of which stopping is rewarded.

drug discrimination procedure

train the rats to press on specific lever depending on what drug is on board, give the rats an injection of drug. rat is learning to base responding on what the drug makes it feel

what is drug response rate?

the greater the reinforcer the faster the animal will respond. some drugs at certain doses may interfere with the ability to respond.

what is a progressive ratio schedule for drugs?

requires the subject to perform increasing numbers of level presses for the presentation of a reinforcer.

what is a breakpoint?

the highest number of levers pressed in a session, the point where the animal no longer finds its rewarding.

what is choice procedure?

models the tendency to repeatedly take a drug by arranging a series of choices between and active drug & a placebo or alternative. trains the animal to understand the pressing different levers = infusion of different drugs.

what is conditioned place preference?

tests the extent to which the reinforcing effects of a drug will condition preference for the location in which those effects were experienced. certain location has been paired with previously rewarding events.

ways to tell drug effects on human behaviour?

• subjective effects; personal accounts

• rating scales (VAS, POMS, ARCI)

• drug state discrimination; exposure to drug or placebo asked to identify the condition they are in.

what effects do drugs have on sensation & perception?

• thresholds

• motor performance

• attention and vigilance

• memory

• response inhibition

absolute threshold

lowest value of a stimulus that can be detected by sensory organs. anything below is not detected.

difference threshold

minimum level of stimuli that a person can detect. e.g., using two point sensitivity test on various parts of the body seeing how close the callipers have to be where a subject stops feeling two points.

what is critical frequency at fusion

when flashing lights will begin to look like a solid light as the frequency increases. drugs will have an effect on when the light appears stable & flashing.

examples of motor performance

• simple reaction time - person must make a response once a signal is given

• complex reaction time - several responses and several signals