PSY1003 WEEK 9 Flashcards
Drug
state the 3 stages for addiction development
- initial use due to price, availabiliy, peer pressure
- habitual use: increased positive-incentive with repeated use in addiction prone resulting in changes in circuitry in brain
- drug craving, relapse
define addiction (by WHO)
state, psychic or sometime physical, resulting from interaction between living organism and drug, characterised by behavioural and other responses that always include compulsion to use on periodic basis in order to experience psychic effect
what is variable ratio reinforcement?
variation in number of needed responses for reward - influences gambling
define tolerance
amount of drug needed to elicit effect, increasing with use
define withdrawal
physiological reaction experienced when not using drug associated with drug dependencee
define sensitisation
prolonged exposure to drug decreases amount needed to elicit response - eg nicotine
explain what withdrawal feels like, including a neural explanation
opposes initial drug effect suggesting is result of same neural change, causing a nervous compensatory change
define conditioned drug tolerance, including heroin users and rats
max tolerance effect seen in environment were drug usually taken - heroin users more likely to overdose in new location (reduce tolerance). rats show place preference and change of tolerance in differing locations
define contingent drug tolerance including rat study with electrical stimulations
tolerance over developed to effect already experienced, studied using rats with electrical stimulation - alcohol inhibits seizure, however only if rat given alcohol before seizure as develop tolerance to alcohol/seizure combination, not seizure/no alcohol
explain the human example for contingent drug tolerance
drinking alcohol then walking, soon become tolerant to activity however if sit down, will suddenly lose tolerance to effect
define cross-tolerance
one drug producing tolerance to other drugs acting by same mechanism
define metabolic tolerance
reduces amount of drug getting to site of action
define functional tolerance
reduces reactivity of sites of action
name 2 method to study bases of drug use
self-report = change over time resulting from social policy such as ban
animal models = behavioural preference test, intra-cranial stimulation
explain oral ingestion
easy + relatively safe, absorption via digestive tract = unpredictable
explain injection administrations
harder to stop overdose, develops collapsed veins and scar tissue
explain the basic basis for how all of drugs worl
synaptic transmission, basis of major cholinergic projections in brain projecting from nucleus basalis to neocortex and thalamus
how do cocaine and amphetamines work
stimulant, increase dopamine = alter dopamine transporter so less removed from synapse
explain how MDMA works
increase serotonin, block reuptake
explain how LSD works
bind to serotonin receptor, interfere with sleep wake cycles
how does caffeine work (including dopamine)
affect adenosine receptors (postsynaptic to dopamine)
explain how cannabis works (including dopamine)
binds to cannabinoid receptor (postsynaptic to dopaine)
explain how alcohol works (including dopamine)
potentiate GABA action (circuits act to increase dopamine)
how do optiates work (including dopamine)
activate pain blocking neuron in spinal - local circuit neuron (potentiates GABA action which increases dopamine)
explain drugs metabolism
enzymes made in liver stimulate active to nonactive conversion eliminating drug ability to pass through lipid cell membra - can’t penetrate BBB
explain physical-dependence perspective
users with sufficient intake levels to induce physical dependence driven by withdrawal symptom to use
explain the impact of the physical-dependence persepctive on early drug addiction programme
break cycles through gradually withdrawaing
