PSY1003 WEEK 9

Question 1

state the 3 stages for addiction development

Answer 1

1. initial use due to price, availabiliy, peer pressure
2. habitual use: increased positive-incentive with repeated use in addiction prone resulting in changes in circuitry in brain
3. drug craving, relapse

Question 2

define addiction (by WHO)

Answer 2

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

Question 3

what is variable ratio reinforcement?

Answer 3

variation in number of needed responses for reward - influences gambling

Question 4

define tolerance

Answer 4

amount of drug needed to elicit effect, increasing with use

Question 5

define withdrawal

Answer 5

physiological reaction experienced when not using drug associated with drug dependencee

Question 6

define sensitisation

Answer 6

prolonged exposure to drug decreases amount needed to elicit response - eg nicotine

Question 7

explain what withdrawal feels like, including a neural explanation

Answer 7

opposes initial drug effect suggesting is result of same neural change, causing a nervous compensatory change

Question 8

define conditioned drug tolerance, including heroin users and rats

Answer 8

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

Question 9

define contingent drug tolerance including rat study with electrical stimulations

Answer 9

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

Question 10

explain the human example for contingent drug tolerance

Answer 10

drinking alcohol then walking, soon become tolerant to activity however if sit down, will suddenly lose tolerance to effect

Question 11

define cross-tolerance

Answer 11

one drug producing tolerance to other drugs acting by same mechanism

Question 12

define metabolic tolerance

Answer 12

reduces amount of drug getting to site of action

Question 13

define functional tolerance

Answer 13

reduces reactivity of sites of action

Question 14

name 2 method to study bases of drug use

Answer 14

self-report = change over time resulting from social policy such as ban
animal models = behavioural preference test, intra-cranial stimulation

Question 15

explain oral ingestion

Answer 15

easy + relatively safe, absorption via digestive tract = unpredictable

Question 16

explain injection administrations

Answer 16

harder to stop overdose, develops collapsed veins and scar tissue

Question 17

explain the basic basis for how all of drugs worl

Answer 17

synaptic transmission, basis of major cholinergic projections in brain projecting from nucleus basalis to neocortex and thalamus

Question 18

how do cocaine and amphetamines work

Answer 18

stimulant, increase dopamine = alter dopamine transporter so less removed from synapse

Question 19

explain how MDMA works

Answer 19

increase serotonin, block reuptake

Question 20

explain how LSD works

Answer 20

bind to serotonin receptor, interfere with sleep wake cycles

Question 21

how does caffeine work (including dopamine)

Answer 21

affect adenosine receptors (postsynaptic to dopamine)

Question 22

explain how cannabis works (including dopamine)

Answer 22

binds to cannabinoid receptor (postsynaptic to dopaine)

Question 23

explain how alcohol works (including dopamine)

Answer 23

potentiate GABA action (circuits act to increase dopamine)

Question 24

how do optiates work (including dopamine)

Answer 24

activate pain blocking neuron in spinal - local circuit neuron (potentiates GABA action which increases dopamine)

Question 25

explain drugs metabolism

Answer 25

enzymes made in liver stimulate active to nonactive conversion eliminating drug ability to pass through lipid cell membra - can’t penetrate BBB

Question 26

explain physical-dependence perspective

Answer 26

users with sufficient intake levels to induce physical dependence driven by withdrawal symptom to use

Question 27

explain the impact of the physical-dependence persepctive on early drug addiction programme

Answer 27

break cycles through gradually withdrawaing